#!/usr/bin/env python
"""
asciidoc - converts an AsciiDoc text file to DocBook, HTML or LinuxDoc

Copyright (C) 2002-2009 Stuart Rackham. Free use of this software is granted
under the terms of the GNU General Public License (GPL).
"""

import sys, os, re, time, traceback, tempfile, subprocess, codecs, locale

### Used by asciidocapi.py ###
VERSION = '8.4.5'   # See CHANGLOG file for version history.

MIN_PYTHON_VERSION = 2.4   # Require this version of Python or better.

#---------------------------------------------------------------------------
# Program constants.
#---------------------------------------------------------------------------
DEFAULT_BACKEND = 'xhtml11'
DEFAULT_DOCTYPE = 'article'
# Allowed substitution options for List, Paragraph and DelimitedBlock
# definition subs entry.
SUBS_OPTIONS = ('specialcharacters','quotes','specialwords',
    'replacements', 'attributes','macros','callouts','normal','verbatim',
    'none','replacements2')
# Default value for unspecified subs and presubs configuration file entries.
SUBS_NORMAL = ('specialcharacters','quotes','attributes',
    'specialwords','replacements','macros','replacements2')
SUBS_VERBATIM = ('specialcharacters','callouts')

NAME_RE = r'(?u)[^\W\d][-\w]*'  # Valid section or attrbibute name.


#---------------------------------------------------------------------------
# Utility functions and classes.
#---------------------------------------------------------------------------

class EAsciiDoc(Exception): pass

class OrderedDict(dict):
    """
    Dictionary ordered by insertion order.
    Python Cookbook: Ordered Dictionary, Submitter: David Benjamin.
    http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/107747
    """
    def __init__(self, d=None, **kwargs):
        self._keys = []
        if d is None: d = kwargs
        dict.__init__(self, d)
    def __delitem__(self, key):
        dict.__delitem__(self, key)
        self._keys.remove(key)
    def __setitem__(self, key, item):
        dict.__setitem__(self, key, item)
        if key not in self._keys: self._keys.append(key)
    def clear(self):
        dict.clear(self)
        self._keys = []
    def copy(self):
        d = dict.copy(self)
        d._keys = self._keys[:]
        return d
    def items(self):
        return zip(self._keys, self.values())
    def keys(self):
        return self._keys
    def popitem(self):
        try:
            key = self._keys[-1]
        except IndexError:
            raise KeyError('dictionary is empty')
        val = self[key]
        del self[key]
        return (key, val)
    def setdefault(self, key, failobj = None):
        dict.setdefault(self, key, failobj)
        if key not in self._keys: self._keys.append(key)
    def update(self, d=None, **kwargs):
        if d is None:
            d = kwargs
        dict.update(self, d)
        for key in d.keys():
            if key not in self._keys: self._keys.append(key)
    def values(self):
        return map(self.get, self._keys)

class AttrDict(dict):
    """
    Like a dictionary except values can be accessed as attributes i.e. obj.foo
    can be used in addition to obj['foo'].
    If an item is not present None is returned.
    """
    def __getattr__(self, key):
        try: return self[key]
        except KeyError, k: return None
    def __setattr__(self, key, value):
        self[key] = value
    def __delattr__(self, key):
        try: del self[key]
        except KeyError, k: raise AttributeError, k
    def __repr__(self):
        return '<AttrDict ' + dict.__repr__(self) + '>'
    def __getstate__(self):
        return dict(self)
    def __setstate__(self,value):
        for k,v in value.items(): self[k]=v

class Trace(object):
    """
    Used in conjunction with the 'trace' attribute to generate diagnostic
    output. There is a single global instance of this class named trace.
    """
    SUBS_NAMES = ('specialcharacters','quotes','specialwords',
                  'replacements', 'attributes','macros','callouts',
                  'replacements2')
    def __init__(self):
        self.name_re = ''        # Regexp pattern to match trace names.
        self.linenos = True
        self.offset = 0
    def __call__(self, name, before, after=None):
        """
        Print trace message if tracing is on and the trace 'name' matches the
        document 'trace' attribute (treated as a regexp).
        The 'before' and 'after' messages are only printed if they differ.
        """
        name_re = document.attributes.get('trace')
        if name_re == 'subs':    # Alias for all the inline substitutions.
            name_re = '|'.join(self.SUBS_NAMES)
        self.name_re = name_re
        if self.name_re is not None:
            msg = message.format(name, 'TRACE: ', self.linenos, offset=self.offset)
            if before != after and re.match(self.name_re,name):
                if is_array(before):
                    before = '\n'.join(before)
                if after is None:
                    msg += '\n%s\n' % before
                else:
                    if is_array(after):
                        after = '\n'.join(after)
                    msg += '\n<<<\n%s\n>>>\n%s\n' % (before,after)
                message.stderr(msg)

class Message:
    """
    Message functions.
    """
    def __init__(self):
        self.linenos = None     # Used to globally override line numbers.
        self.messages = []

    def stderr(self,line=''):
        self.messages.append(line)
        if __name__ == '__main__':
            sys.stderr.write(line+os.linesep)

    def verbose(self, msg,linenos=True):
        if config.verbose:
            msg = self.format(msg,linenos=linenos)
            self.stderr(msg)

    def warning(self, msg,linenos=True,offset=0):
        msg = self.format(msg,'WARNING: ',linenos,offset=offset)
        document.has_warnings = True
        self.stderr(msg)

    def deprecated(self, msg, linenos=True):
        msg = self.format(msg, 'DEPRECATED: ', linenos)
        self.stderr(msg)

    def format(self, msg, prefix='', linenos=True, cursor=None, offset=0):
        """Return formatted message string."""
        if self.linenos is not False and ((linenos or self.linenos) and reader.cursor):
            if cursor is None:
                cursor = reader.cursor
            prefix += '%s: line %d: ' % (os.path.basename(cursor[0]),cursor[1]+offset)
        return prefix + msg

    def error(self, msg, cursor=None, halt=False):
        """
        Report fatal error.
        If halt=True raise EAsciiDoc exception.
        If halt=False don't exit application, continue in the hope of reporting
        all fatal errors finishing with a non-zero exit code.
        """
        if halt:
            raise EAsciiDoc, self.format(msg,linenos=False,cursor=cursor)
        else:
            msg = self.format(msg,'ERROR: ',cursor=cursor)
            self.stderr(msg)
            document.has_errors = True

    def unsafe(self, msg):
        self.error('unsafe: '+msg)


def file_in(fname, directory):
    """Return True if file fname resides inside directory."""
    assert os.path.isfile(fname)
    # Empty directory (not to be confused with None) is the current directory.
    if directory == '':
        directory = os.getcwd()
    else:
        assert os.path.isdir(directory)
        directory = os.path.realpath(directory)
    fname = os.path.realpath(fname)
    return os.path.commonprefix((directory, fname)) == directory

def safe():
    return document.safe

def is_safe_file(fname, directory=None):
    # A safe file must reside in directory directory (defaults to the source
    # file directory).
    if directory is None:
        if document.infile == '<stdin>':
           return not safe()
        directory = os.path.dirname(document.infile)
    elif directory == '':
        directory = '.'
    return not safe() or file_in(fname, directory)

def safe_filename(fname, parentdir):
    """
    Return file name which must reside in the parent file directory.
    Return None if file is not found or not safe.
    """
    if not os.path.isabs(fname):
        # Include files are relative to parent document
        # directory.
        fname = os.path.join(parentdir,fname)
    if not os.path.isfile(fname):
        message.warning('include file not found: %s' % fname)
        return None
    if not is_safe_file(fname, parentdir):
        message.unsafe('include file: %s' % fname)
        return None
    return fname

def assign(dst,src):
    """Assign all attributes from 'src' object to 'dst' object."""
    for a,v in src.__dict__.items():
        setattr(dst,a,v)

def strip_quotes(s):
    """Trim white space and, if necessary, quote characters from s."""
    s = s.strip()
    # Strip quotation mark characters from quoted strings.
    if len(s) >= 3 and s[0] == '"' and s[-1] == '"':
        s = s[1:-1]
    return s

def is_re(s):
    """Return True if s is a valid regular expression else return False."""
    try: re.compile(s)
    except: return False
    else: return True

def re_join(relist):
    """Join list of regular expressions re1,re2,... to single regular
    expression (re1)|(re2)|..."""
    if len(relist) == 0:
        return None
    result = []
    # Delete named groups to avoid ambiguity.
    for s in relist:
        result.append(re.sub(r'\?P<\S+?>','',s))
    result = ')|('.join(result)
    result = '('+result+')'
    return result

def validate(value,rule,errmsg):
    """Validate value against rule expression. Throw EAsciiDoc exception with
    errmsg if validation fails."""
    try:
        if not eval(rule.replace('$',str(value))):
            raise EAsciiDoc,errmsg
    except Exception:
        raise EAsciiDoc,errmsg
    return value

def lstrip_list(s):
    """
    Return list with empty items from start of list removed.
    """
    for i in range(len(s)):
        if s[i]: break
    else:
        return []
    return s[i:]

def rstrip_list(s):
    """
    Return list with empty items from end of list removed.
    """
    for i in range(len(s)-1,-1,-1):
        if s[i]: break
    else:
        return []
    return s[:i+1]

def strip_list(s):
    """
    Return list with empty items from start and end of list removed.
    """
    s = lstrip_list(s)
    s = rstrip_list(s)
    return s

def is_array(obj):
    """
    Return True if object is list or tuple type.
    """
    return isinstance(obj,list) or isinstance(obj,tuple)

def dovetail(lines1, lines2):
    """
    Append list or tuple of strings 'lines2' to list 'lines1'.  Join the last
    non-blank item in 'lines1' with the first non-blank item in 'lines2' into a
    single string.
    """
    assert is_array(lines1)
    assert is_array(lines2)
    lines1 = strip_list(lines1)
    lines2 = strip_list(lines2)
    if not lines1 or not lines2:
        return list(lines1) + list(lines2)
    result = list(lines1[:-1])
    result.append(lines1[-1] + lines2[0])
    result += list(lines2[1:])
    return result

def dovetail_tags(stag,content,etag):
    """Merge the end tag with the first content line and the last
    content line with the end tag. This ensures verbatim elements don't
    include extraneous opening and closing line breaks."""
    return dovetail(dovetail(stag,content), etag)

def parse_attributes(attrs,dict):
    """Update a dictionary with name/value attributes from the attrs string.
    The attrs string is a comma separated list of values and keyword name=value
    pairs. Values must preceed keywords and are named '1','2'... The entire
    attributes list is named '0'. If keywords are specified string values must
    be quoted. Examples:

    attrs: ''
    dict: {}

    attrs: 'hello,world'
    dict: {'2': 'world', '0': 'hello,world', '1': 'hello'}

    attrs: '"hello", planet="earth"'
    dict: {'planet': 'earth', '0': '"hello",planet="earth"', '1': 'hello'}
    """
    def f(*args,**keywords):
        # Name and add aguments '1','2'... to keywords.
        for i in range(len(args)):
            if not str(i+1) in keywords:
                keywords[str(i+1)] = args[i]
        return keywords

    if not attrs:
        return
    dict['0'] = attrs
    # Replace line separators with spaces so line spanning works.
    s = re.sub(r'\s', ' ', attrs)
    try:
        d = eval('f('+s+')')
        # Attributes must evaluate to strings, numbers or None.
        for v in d.values():
            if not (isinstance(v,str) or isinstance(v,int) or isinstance(v,float) or v is None):
                raise
    except Exception:
        s = s.replace('"','\\"')
        s = s.split(',')
        s = map(lambda x: '"' + x.strip() + '"', s)
        s = ','.join(s)
        try:
            d = eval('f('+s+')')
        except Exception:
            return  # If there's a syntax error leave with {0}=attrs.
        for k in d.keys():  # Drop any empty positional arguments.
            if d[k] == '': del d[k]
    dict.update(d)
    assert len(d) > 0

def parse_named_attributes(s,attrs):
    """Update a attrs dictionary with name="value" attributes from the s string.
    Returns False if invalid syntax.
    Example:
    attrs: 'star="sun",planet="earth"'
    dict: {'planet':'earth', 'star':'sun'}
    """
    def f(**keywords): return keywords

    try:
        d = eval('f('+s+')')
        attrs.update(d)
        return True
    except Exception:
        return False

def parse_list(s):
    """Parse comma separated string of Python literals. Return a tuple of of
    parsed values."""
    try:
        result = eval('tuple(['+s+'])')
    except Exception:
        raise EAsciiDoc,'malformed list: '+s
    return result

def parse_options(options,allowed,errmsg):
    """Parse comma separated string of unquoted option names and return as a
    tuple of valid options. 'allowed' is a list of allowed option values.
    If allowed=() then all legitimate names are allowed.
    'errmsg' is an error message prefix if an illegal option error is thrown."""
    result = []
    if options:
        for s in re.split(r'\s*,\s*',options):
            if (allowed and s not in allowed) or not is_name(s):
                raise EAsciiDoc,'%s: %s' % (errmsg,s)
            result.append(s)
    return tuple(result)

def symbolize(s):
    """Drop non-symbol characters and convert to lowercase."""
    return re.sub(r'(?u)[^\w\-_]', '', s).lower()

def is_name(s):
    """Return True if s is valid attribute, macro or tag name
    (starts with alpha containing alphanumeric and dashes only)."""
    return re.match(r'^'+NAME_RE+r'$',s) is not None

def subs_quotes(text):
    """Quoted text is marked up and the resulting text is
    returned."""
    keys = config.quotes.keys()
    for q in keys:
        i = q.find('|')
        if i != -1 and q != '|' and q != '||':
            lq = q[:i]      # Left quote.
            rq = q[i+1:]    # Right quote.
        else:
            lq = rq = q
        tag = config.quotes[q]
        # Unconstrained quotes prefix the tag name with a hash.
        if tag[0] == '#':
            tag = tag[1:]
            # Unconstrained quotes can appear anywhere.
            reo = re.compile(r'(?msu)(^|.)(\[(?P<attrlist>[^[\]]+?)\])?' \
                    + r'(?:' + re.escape(lq) + r')' \
                    + r'(?P<content>.+?)(?:'+re.escape(rq)+r')')
        else:
            # The text within constrained quotes must be bounded by white space.
            # Non-word (\W) characters are allowed at boundaries to accomodate
            # enveloping quotes.
            reo = re.compile(r'(?msu)(^|\W)(\[(?P<attrlist>[^[\]]+?)\])?' \
                + r'(?:' + re.escape(lq) + r')' \
                + r'(?P<content>\S|\S.*?\S)(?:'+re.escape(rq)+r')(?=\W|$)')
        pos = 0
        while True:
            mo = reo.search(text,pos)
            if not mo: break
            if text[mo.start()] == '\\':
                # Delete leading backslash.
                text = text[:mo.start()] + text[mo.start()+1:]
                # Skip past start of match.
                pos = mo.start() + 1
            else:
                attrlist = {}
                parse_attributes(mo.group('attrlist'), attrlist)
                stag,etag = config.tag(tag, attrlist)
                s = mo.group(1) + stag + mo.group('content') + etag
                text = text[:mo.start()] + s + text[mo.end():]
                pos = mo.start() + len(s)
    return text

def subs_tag(tag,dict={}):
    """Perform attribute substitution and split tag string returning start, end
    tag tuple (c.f. Config.tag())."""
    if not tag:
        return [None,None]
    s = subs_attrs(tag,dict)
    if not s:
        message.warning('tag \'%s\' dropped: contains undefined attribute' % tag)
        return [None,None]
    result = s.split('|')
    if len(result) == 1:
        return result+[None]
    elif len(result) == 2:
        return result
    else:
        raise EAsciiDoc,'malformed tag: %s' % tag

def parse_entry(entry, dict=None, unquote=False, unique_values=False,
        allow_name_only=False, escape_delimiter=True):
    """Parse name=value entry to dictionary 'dict'. Return tuple (name,value)
    or None if illegal entry.
    If name= then value is set to ''.
    If name and allow_name_only=True then value is set to ''.
    If name! and allow_name_only=True then value is set to None.
    Leading and trailing white space is striped from 'name' and 'value'.
    'name' can contain any printable characters.
    If the '=' delimiter character is allowed in  the 'name' then
    it must be escaped with a backslash and escape_delimiter must be True.
    If 'unquote' is True leading and trailing double-quotes are stripped from
    'name' and 'value'.
    If unique_values' is True then dictionary entries with the same value are
    removed before the parsed entry is added."""
    if escape_delimiter:
        mo = re.search(r'(?:[^\\](=))',entry)
    else:
        mo = re.search(r'(=)',entry)
    if mo:  # name=value entry.
        if mo.group(1):
            name = entry[:mo.start(1)]
            if escape_delimiter:
                name = name.replace(r'\=','=')  # Unescape \= in name.
            value = entry[mo.end(1):]
    elif allow_name_only and entry:         # name or name! entry.
        name = entry
        if name[-1] == '!':
            name = name[:-1]
            value = None
        else:
            value = ''
    else:
        return None
    if unquote:
        name = strip_quotes(name)
        if value is not None:
            value = strip_quotes(value)
    else:
        name = name.strip()
        if value is not None:
            value = value.strip()
    if not name:
        return None
    if dict is not None:
        if unique_values:
            for k,v in dict.items():
                if v == value: del dict[k]
        dict[name] = value
    return name,value

def parse_entries(entries, dict, unquote=False, unique_values=False,
        allow_name_only=False,escape_delimiter=True):
    """Parse name=value entries from  from lines of text in 'entries' into
    dictionary 'dict'. Blank lines are skipped."""
    entries = config.expand_templates(entries)
    for entry in entries:
        if entry and not parse_entry(entry, dict, unquote, unique_values,
                allow_name_only, escape_delimiter):
            raise EAsciiDoc,'malformed section entry: %s' % entry

def load_conf_file(sections, fname, dir, namepat=NAME_RE):
    """Loads sections dictionary with sections from file fname.
    Existing sections are overlaid. Silently skips missing configuration
    files."""
    if dir:
        fname = os.path.join(dir, fname)
    # Sliently skip missing configuration file.
    if not os.path.isfile(fname):
        return
    reo = re.compile(r'^\[(?P<section>'+namepat+')\]\s*$')
    section,contents = '',[]
    for line in open(fname):
        if line and line[0] == '#': # Skip comment lines.
            continue
        line = line.rstrip()
        found = reo.findall(line)
        if found:
            if section:             # Store previous section.
                sections[section] = contents
            section = found[0].lower()
            contents = []
        else:
            contents.append(line)
    if section and contents:        # Store last section.
        sections[section] = contents

def dump_section(name,dict,f=sys.stdout):
    """Write parameters in 'dict' as in configuration file section format with
    section 'name'."""
    f.write('[%s]%s' % (name,writer.newline))
    for k,v in dict.items():
        k = str(k)
        k = k.replace('=',r'\=')    # Escape = in name.
        # Quote if necessary.
        if len(k) != len(k.strip()):
            k = '"'+k+'"'
        if v and len(v) != len(v.strip()):
            v = '"'+v+'"'
        if v is None:
            # Don't dump undefined attributes.
            continue
        else:
            s = k+'='+v
        if s[0] == '#':
            s = '\\' + s    # Escape so not treated as comment lines.
        f.write('%s%s' % (s,writer.newline))
    f.write(writer.newline)

def update_attrs(attrs,dict):
    """Update 'attrs' dictionary with parsed attributes in dictionary 'dict'."""
    for k,v in dict.items():
        if not is_name(k):
            raise EAsciiDoc,'illegal attribute name: %s' % k
        attrs[k] = v

def filter_lines(filter_cmd, lines, attrs={}):
    """
    Run 'lines' through the 'filter_cmd' shell command and return the result.
    The 'attrs' dictionary contains additional filter attributes.
    """
    def findfilter(name,dir,filter):
        """Find filter file 'fname' with style name 'name' in directory
        'dir'. Return found file path or None if not found."""
        if name:
            result = os.path.join(dir,'filters',name,filter)
            if os.path.isfile(result):
                return result
        result = os.path.join(dir,'filters',filter)
        if os.path.isfile(result):
            return result
        return None

    # Return input lines if there's not filter.
    if not filter_cmd or not filter_cmd.strip():
        return lines
    # Perform attributes substitution on the filter command.
    s = subs_attrs(filter_cmd, attrs)
    if not s:
        raise EAsciiDoc,'undefined filter attribute in command: %s' % filter_cmd
    filter_cmd = s.strip()
    # Parse for quoted and unquoted command and command tail.
    # Double quoted.
    mo = re.match(r'^"(?P<cmd>[^"]+)"(?P<tail>.*)$', filter_cmd)
    if not mo:
        # Single quoted.
        mo = re.match(r"^'(?P<cmd>[^']+)'(?P<tail>.*)$", filter_cmd)
        if not mo:
            # Unquoted catch all.
            mo = re.match(r'^(?P<cmd>\S+)(?P<tail>.*)$', filter_cmd)
    cmd = mo.group('cmd').strip()
    found = None
    if not os.path.dirname(cmd):
        # Filter command has no directory path so search filter directories.
        filtername = attrs.get('style')
        if USER_DIR:
            found = findfilter(filtername, USER_DIR, cmd)
        if not found:
            found = findfilter(filtername, CONF_DIR, cmd)
        if not found:
            found = findfilter(filtername, APP_DIR, cmd)
    else:
        if os.path.isfile(cmd):
            found = cmd
        else:
            message.warning('filter not found: %s' % cmd)
    if found:
        filter_cmd = '"' + found + '"' + mo.group('tail')
    if sys.platform == 'win32':
        # Windows doesn't like running scripts directly so explicitly
        # specify interpreter.
        if found:
            if cmd.endswith('.py'):
                filter_cmd = 'python ' + filter_cmd
            elif cmd.endswith('.rb'):
                filter_cmd = 'ruby ' + filter_cmd
    message.verbose('filtering: ' + filter_cmd)
    try:
        p = subprocess.Popen(filter_cmd, shell=True,
                stdin=subprocess.PIPE, stdout=subprocess.PIPE)
        output = p.communicate(os.linesep.join(lines))[0]
    except Exception:
        raise EAsciiDoc,'filter error: %s: %s' % (filter_cmd, sys.exc_info()[1])
    if output:
        result = [s.rstrip() for s in output.split(os.linesep)]
    else:
        result = []
    filter_status = p.wait()
    if filter_status:
        message.warning('filter non-zero exit code: %s: returned %d' %
               (filter_cmd, filter_status))
    if lines and not result:
        message.warning('no output from filter: %s' % filter_cmd)
    return result

def system(name, args, is_macro=False):
    """
    Evaluate a system attribute ({name:args}) or system block macro
    (name::[args]). If is_macro is True then we are processing a system
    block macro otherwise it's a system attribute.
    NOTE: The include1 attribute is used internally by the include1::[] macro
    and is not for public use.
    """
    if is_macro:
        syntax = '%s::[%s]'
        separator = '\n'
    else:
        syntax = '{%s:%s}'
        separator = writer.newline
    if name not in ('eval','sys','sys2','include','include1'):
        if is_macro:
            msg = 'illegal system macro name: %s' % name
        else:
            msg = 'illegal system attribute name: %s' % name
        message.warning(msg)
        return None
    if is_macro:
        s = subs_attrs(args)
        if s is None:
            message.warning('skipped %s: undefined attribute in: %s' % (name,args))
            return None
        args = s
    if name != 'include1':
        message.verbose(('evaluating: '+syntax) % (name,args))
    if safe() and name not in ('include','include1'):
        message.unsafe(syntax % (name,args))
        return None
    result = None
    if name == 'eval':
        try:
            result = eval(args)
            if result is True:
                result = ''
            elif result is False:
                result = None
            elif result is not None:
                result = str(result)
        except Exception:
            message.warning((syntax+': expression evaluation error') % (name,args))
    elif name in ('sys','sys2'):
        result = ''
        fd,tmp = tempfile.mkstemp()
        os.close(fd)
        try:
            cmd = args
            cmd = cmd + (' > %s' % tmp)
            if name == 'sys2':
                cmd = cmd + ' 2>&1'
            if os.system(cmd):
                message.warning((syntax+': non-zero exit status') % (name,args))
            try:
                if os.path.isfile(tmp):
                    lines = [s.rstrip() for s in open(tmp)]
                else:
                    lines = []
            except Exception:
                raise EAsciiDoc,(syntax+': temp file read error') % (name,args)
            result = separator.join(lines)
        finally:
            if os.path.isfile(tmp):
                os.remove(tmp)
    elif name == 'include':
        if not os.path.exists(args):
            message.warning((syntax+': file does not exist') % (name,args))
        elif not is_safe_file(args):
            message.unsafe(syntax % (name,args))
        else:
            result = [s.rstrip() for s in open(args)]
            if result:
                result = subs_attrs(result)
                result = separator.join(result)
                result = result.expandtabs(reader.tabsize)
            else:
                result = ''
    elif name == 'include1':
        result = separator.join(config.include1[args])
    else:
        assert False
    return result

def subs_attrs(lines, dictionary=None):
    """Substitute 'lines' of text with attributes from the global
    document.attributes dictionary and from 'dictionary' ('dictionary'
    entries take precedence). Return a tuple of the substituted lines.  'lines'
    containing undefined attributes are deleted. If 'lines' is a string then
    return a string.

    - Attribute references are substituted in the following order: simple,
      conditional, system.
    - Attribute references inside 'dictionary' entry values are substituted.
    """

    def end_brace(text,start):
        """Return index following end brace that matches brace at start in
        text."""
        assert text[start] == '{'
        n = 0
        result = start
        for c in text[start:]:
            # Skip braces that are followed by a backslash.
            if result == len(text)-1 or text[result+1] != '\\':
                if c == '{': n = n + 1
                elif c == '}': n = n - 1
            result = result + 1
            if n == 0: break
        return result

    if type(lines) == str:
        string_result = True
        lines = [lines]
    else:
        string_result = False
        lines = list(lines)
    if dictionary is None:
        attrs = document.attributes
    else:
        # Remove numbered document attributes so they don't clash with
        # attribute list positional attributes.
        attrs = {}
        for k,v in document.attributes.items():
            if not re.match(r'^\d+$', k):
                attrs[k] = v
        # Substitute attribute references inside dictionary values.
        dictionary = dictionary.copy()
        for k,v in dictionary.items():
            if v is None:
                del dictionary[k]
            else:
                v = subs_attrs(str(v))
                if v is None:
                    del dictionary[k]
                else:
                    dictionary[k] = v
        attrs.update(dictionary)
    # Substitute all attributes in all lines.
    for i in range(len(lines)-1,-1,-1): # Reverse iterate lines.
        text = lines[i]
        # Make it easier for regular expressions.
        text = text.replace('\\{','{\\')
        text = text.replace('\\}','}\\')
        # Expand simple attributes ({name}).
        # Nested attributes not allowed.
        reo = re.compile(r'(?su)\{(?P<name>[^\\\W][-\w]*?)\}(?!\\)')
        pos = 0
        while True:
            mo = reo.search(text,pos)
            if not mo: break
            s =  attrs.get(mo.group('name'))
            if s is None:
                pos = mo.end()
            else:
                s = str(s)
                text = text[:mo.start()] + s + text[mo.end():]
                pos = mo.start() + len(s)
        # Expand conditional attributes.
        reo = re.compile(r'(?su)\{(?P<name>[^\\\W][-\w]*?)' \
                         r'(?P<op>\=|\?|!|#|%|@|\$)'        \
                         r'(?P<value>.*?)\}(?!\\)')
        pos = 0
        while True:
            mo = reo.search(text,pos)
            if not mo: break
            attr = mo.group()
            name =  mo.group('name')
            lval =  attrs.get(name)
            op = mo.group('op')
            # mo.end() is not good enough because '{x={y}}' matches '{x={y}'.
            end = end_brace(text,mo.start())
            rval = text[mo.start('value'):end-1]
            if lval is None:
                if op == '=': s = rval
                elif op == '?': s = ''
                elif op == '!': s = rval
                elif op == '#': s = '{'+name+'}'    # So the line is dropped.
                elif op == '%': s = rval
                elif op in ('@','$'):
                    s = '{'+name+'}'                # So the line is dropped.
                else:
                    assert False, 'illegal attribute: %s' % attr
            else:
                if op == '=': s = lval
                elif op == '?': s = rval
                elif op == '!': s = ''
                elif op == '#': s = rval
                elif op == '%': s = '{zzzzz}'       # So the line is dropped.
                elif op in ('@','$'):
                    v = re.split(r'(?<!\\):',rval)
                    if len(v) not in (2,3):
                        message.error('illegal attribute syntax: %s' % attr)
                        s = ''
                    elif not is_re('^'+v[0]+'$'):
                        message.error('illegal attribute regexp: %s' % attr)
                        s = ''
                    else:
                        v = [s.replace('\\:',':') for s in v]
                        re_mo = re.match('^'+v[0]+'$',lval)
                        if op == '@':
                            if re_mo:
                                s = v[1]            # {<name>@<re>:<v1>[:<v2>]}
                            else:
                                if len(v) == 3:     # {<name>@<re>:<v1>:<v2>}
                                    s = v[2]
                                else:               # {<name>@<re>:<v1>}
                                    s = ''
                        else:
                            if re_mo:
                                if len(v) == 2:     # {<name>$<re>:<v1>}
                                    s = v[1]
                                elif v[1] == '':    # {<name>$<re>::<v2>}
                                    s = '{zzzzz}'   # So the line is dropped.
                                else:               # {<name>$<re>:<v1>:<v2>}
                                    s = v[1]
                            else:
                                if len(v) == 2:     # {<name>$<re>:<v1>}
                                    s = '{zzzzz}'   # So the line is dropped.
                                else:               # {<name>$<re>:<v1>:<v2>}
                                    s = v[2]
                else:
                    assert False, 'illegal attribute: %s' % attr
            s = str(s)
            text = text[:mo.start()] + s + text[end:]
            pos = mo.start() + len(s)
        # Drop line if it contains  unsubstituted {name} references.
        skipped = re.search(r'(?su)\{[^\\\W][-\w]*?\}(?!\\)', text)
        if skipped:
            del lines[i]
            continue;
        # Expand system attributes.
        reo = re.compile(r'(?su)\{(?P<action>[^\\\W][-\w]*?):(?P<expr>.*?)\}(?!\\)')
        skipped = False
        pos = 0
        while True:
            mo = reo.search(text,pos)
            if not mo: break
            expr = mo.group('expr')
            expr = expr.replace('{\\','{')
            expr = expr.replace('}\\','}')
            s = system(mo.group('action'),expr)
            if s is None:
                skipped = True
                break
            text = text[:mo.start()] + s + text[mo.end():]
            pos = mo.start() + len(s)
        # Drop line if the action returns None.
        if skipped:
            del lines[i]
            continue;
        # Remove backslash from escaped entries.
        text = text.replace('{\\','{')
        text = text.replace('}\\','}')
        lines[i] = text
    if string_result:
        if lines:
            return '\n'.join(lines)
        else:
            return None
    else:
        return tuple(lines)

def char_encoding():
    encoding = document.attributes.get('encoding')
    if encoding:
        try:
            codecs.lookup(encoding)
        except LookupError,e:
            raise EAsciiDoc,str(e)
    return encoding

def char_len(s):
    return len(char_decode(s))

def char_decode(s):
    if char_encoding():
        try:
            return s.decode(char_encoding())
        except Exception:
            raise EAsciiDoc, \
                "'%s' codec can't decode \"%s\"" % (char_encoding(), s)
    else:
        return s

def char_encode(s):
    if char_encoding():
        return s.encode(char_encoding())
    else:
        return s

def time_str(t):
    """Convert seconds since the Epoch to formatted local time string."""
    t = time.localtime(t)
    s = time.strftime('%H:%M:%S',t)
    if time.daylight:
        result = s + ' ' + time.tzname[1]
    else:
        result = s + ' ' + time.tzname[0]
    # Attempt to convert the localtime to the output encoding.
    try:
        result = char_encode(result.decode(locale.getdefaultlocale()[1]))
    except Exception:
        pass
    return result

def date_str(t):
    """Convert seconds since the Epoch to formatted local date string."""
    t = time.localtime(t)
    return time.strftime('%Y-%m-%d',t)


class Lex:
    """Lexical analysis routines. Static methods and attributes only."""
    prev_element = None
    prev_cursor = None
    def __init__(self):
        raise AssertionError,'no class instances allowed'
    @staticmethod
    def next():
        """Returns class of next element on the input (None if EOF).  The
        reader is assumed to be at the first line following a previous element,
        end of file or line one.  Exits with the reader pointing to the first
        line of the next element or EOF (leading blank lines are skipped)."""
        reader.skip_blank_lines()
        if reader.eof(): return None
        # Optimization: If we've already checked for an element at this
        # position return the element.
        if Lex.prev_element and Lex.prev_cursor == reader.cursor:
            return Lex.prev_element
        if AttributeEntry.isnext():
            result = AttributeEntry
        elif AttributeList.isnext():
            result = AttributeList
        elif Title.isnext():
            result = Title
        elif macros.isnext():
            result = macros.current
        elif lists.isnext():
            result = lists.current
        elif blocks.isnext():
            result = blocks.current
        elif tables_OLD.isnext():
            result = tables_OLD.current
        elif tables.isnext():
            result = tables.current
        elif BlockTitle.isnext():
            result = BlockTitle
        else:
            if not paragraphs.isnext():
                raise EAsciiDoc,'paragraph expected'
            result = paragraphs.current
        # Optimization: Cache answer.
        Lex.prev_cursor = reader.cursor
        Lex.prev_element = result
        return result

    @staticmethod
    def canonical_subs(options):
        """Translate composite subs values."""
        if len(options) == 1:
            if options[0] == 'none':
                options = ()
            elif options[0] == 'normal':
                options = config.subsnormal
            elif options[0] == 'verbatim':
                options = config.subsverbatim
        return options

    @staticmethod
    def subs_1(s,options):
        """Perform substitution specified in 'options' (in 'options' order) on
        Does not process 'attributes' substitutions."""
        if not s:
            return s
        result = s
        options = Lex.canonical_subs(options)
        for o in options:
            if o == 'specialcharacters':
                result = config.subs_specialchars(result)
            elif o == 'attributes':
                result = subs_attrs(result)
            elif o == 'quotes':
                result = subs_quotes(result)
            elif o == 'specialwords':
                result = config.subs_specialwords(result)
            elif o in ('replacements','replacements2'):
                result = config.subs_replacements(result,o)
            elif o == 'macros':
                result = macros.subs(result)
            elif o == 'callouts':
                result = macros.subs(result,callouts=True)
            else:
                raise EAsciiDoc,'illegal substitution option: %s' % o
            trace(o, s, result)
            if not result:
                break
        return result

    @staticmethod
    def subs(lines,options):
        """Perform inline processing specified by 'options' (in 'options'
        order) on sequence of 'lines'."""
        if not lines or not options:
            return lines
        options = Lex.canonical_subs(options)
        # Join lines so quoting can span multiple lines.
        para = '\n'.join(lines)
        if 'macros' in options:
            para = macros.extract_passthroughs(para)
        for o in options:
            if o == 'attributes':
                # If we don't substitute attributes line-by-line then a single
                # undefined attribute will drop the entire paragraph.
                lines = subs_attrs(para.split('\n'))
                para = '\n'.join(lines)
            else:
                para = Lex.subs_1(para,(o,))
        if 'macros' in options:
            para = macros.restore_passthroughs(para)
        return para.splitlines()

    @staticmethod
    def set_margin(lines, margin=0):
        """Utility routine that sets the left margin to 'margin' space in a
        block of non-blank lines."""
        # Calculate width of block margin.
        lines = list(lines)
        width = len(lines[0])
        for s in lines:
            i = re.search(r'\S',s).start()
            if i < width: width = i
        # Strip margin width from all lines.
        for i in range(len(lines)):
            lines[i] = ' '*margin + lines[i][width:]
        return lines

#---------------------------------------------------------------------------
# Document element classes parse AsciiDoc reader input and write DocBook writer
# output.
#---------------------------------------------------------------------------
class Document:
    def __init__(self):
        self.doctype = None     # 'article','manpage' or 'book'.
        self.backend = None     # -b option argument.
        self.infile = None      # Source file name.
        self.outfile = None     # Output file name.
        self.attributes = {}
        self.level = 0          # 0 => front matter. 1,2,3 => sect1,2,3.
        self.has_errors = False # Set true if processing errors were flagged.
        self.has_warnings = False # Set true if warnings were flagged.
        self.safe = True        # Default safe mode.
    def update_attributes(self):
        # Set implicit attributes.
        if self.infile and os.path.exists(self.infile):
            t = os.path.getmtime(self.infile)
        elif self.infile == '<stdin>':
            t = time.time()
        else:
            t = None
        if t:
            self.attributes['doctime'] = time_str(t)
            self.attributes['docdate'] = date_str(t)
        t = time.time()
        self.attributes['localtime'] = time_str(t)
        self.attributes['localdate'] = date_str(t)
        self.attributes['asciidoc-version'] = VERSION
        self.attributes['backend'] = document.backend
        self.attributes['doctype'] = document.doctype
        self.attributes['backend-'+document.backend] = ''
        self.attributes['doctype-'+document.doctype] = ''
        self.attributes[document.backend+'-'+document.doctype] = ''
        self.attributes['asciidoc-file'] = APP_FILE
        self.attributes['asciidoc-dir'] = APP_DIR
        self.attributes['user-dir'] = USER_DIR
        if self.infile != '<stdin>':
            self.attributes['infile'] = self.infile
            self.attributes['indir'] = os.path.dirname(self.infile)
            self.attributes['docfile'] = self.infile
            self.attributes['docdir'] = os.path.dirname(self.infile)
            self.attributes['docname'] = os.path.splitext(
                    os.path.basename(self.infile))[0]
        if config.verbose:
            self.attributes['verbose'] = ''
        # Update with configuration file attributes.
        self.attributes.update(config.conf_attrs)
        # Update with command-line attributes.
        self.attributes.update(config.cmd_attrs)
        # Extract miscellaneous configuration section entries from attributes.
        config.load_miscellaneous(config.conf_attrs)
        config.load_miscellaneous(config.cmd_attrs)
        self.attributes['newline'] = config.newline
        if self.outfile:
            if self.outfile != '<stdout>':
                self.attributes['outfile'] = self.outfile
                self.attributes['outdir'] = os.path.dirname(self.outfile)
                self.attributes['docname'] = os.path.splitext(
                        os.path.basename(self.outfile))[0]
                ext = os.path.splitext(self.outfile)[1][1:]
            elif config.outfilesuffix:
                ext = config.outfilesuffix[1:]
            else:
                ext = ''
            if ext:
                self.attributes['filetype'] = ext
                self.attributes['filetype-'+ext] = ''
    def load_lang(self,linenos=False):
        """
        Load language configuration file.
        """
        lang = self.attributes.get('lang')
        message.linenos = linenos
        if lang:
            if not config.load_lang(lang):
                message.error('missing language conf file: lang-%s.conf' % lang)
            self.attributes['lang'] = lang  # Reinstate new lang attribute.
        else:
            message.error('language attribute (lang) is not defined')
        message.linenos = None  # Restore default line number behavior.
    def set_deprecated_attribute(self,old,new):
        """
        Ensures the 'old' name of an attribute that was renamed to 'new' is
        still honored.
        """
        if self.attributes.get(new) is None:
            if self.attributes.get(old) is not None:
                self.attributes[new] = self.attributes[old]
        else:
            self.attributes[old] = self.attributes[new]
    def translate(self):
        assert self.doctype in ('article','manpage','book'), \
            'illegal document type'
        assert self.level == 0
        config.expand_all_templates()
        self.load_lang()
        # Skip leading comments and attribute entries.
        finished = False
        attr_count = 0
        while not finished:
            finished = True
            if blocks.isnext() and 'skip' in blocks.current.options:
                finished = False
                blocks.current.translate()
            if macros.isnext() and macros.current.name == 'comment':
                finished = False
                macros.current.translate()
            if AttributeEntry.isnext():
                finished = False
                AttributeEntry.translate()
                if AttributeEntry.name == 'lang':
                    self.load_lang(linenos=True)
                    if attr_count > 0:
                        message.error('lang attribute should be first entry')
                attr_count += 1
        message.verbose('writing: '+writer.fname,False)
        # Process document header.
        has_header =  Lex.next() is Title and Title.level == 0
        if self.doctype == 'manpage' and not has_header:
            message.error('manpage document title is mandatory')
        if has_header:
            Header.translate()
            # Command-line entries override header derived entries.
            self.attributes.update(config.cmd_attrs)
            # DEPRECATED: revision renamed to revnumber.
            self.set_deprecated_attribute('revision','revnumber')
            # DEPRECATED: date renamed to revdate.
            self.set_deprecated_attribute('date','revdate')
            if config.header_footer:
                hdr = config.subs_section('header',{})
                writer.write(hdr,trace='header')
            if self.doctype in ('article','book'):
                # Translate 'preamble' (untitled elements between header
                # and first section title).
                if Lex.next() is not Title:
                    stag,etag = config.section2tags('preamble')
                    writer.write(stag,trace='preamble open')
                    Section.translate_body()
                    writer.write(etag,trace='preamble close')
        else:
            document.process_author_names()
            if config.header_footer:
                hdr = config.subs_section('header',{})
                writer.write(hdr,trace='header')
            if Lex.next() is not Title:
                Section.translate_body()
        # Process remaining sections.
        while not reader.eof():
            if Lex.next() is not Title:
                raise EAsciiDoc,'section title expected'
            Section.translate()
        Section.setlevel(0) # Write remaining unwritten section close tags.
        # Substitute document parameters and write document footer.
        if config.header_footer:
            ftr = config.subs_section('footer',{})
            writer.write(ftr,trace='footer')
    def parse_author(self,s):
        """ Return False if the author is malformed."""
        attrs = self.attributes # Alias for readability.
        s = s.strip()
        mo = re.match(r'^(?P<name1>[^<>\s]+)'
                '(\s+(?P<name2>[^<>\s]+))?'
                '(\s+(?P<name3>[^<>\s]+))?'
                '(\s+<(?P<email>\S+)>)?$',s)
        if not mo:
            message.error('malformed author: %s' % s)
            return False
        firstname = mo.group('name1')
        if mo.group('name3'):
            middlename = mo.group('name2')
            lastname = mo.group('name3')
        else:
            middlename = None
            lastname = mo.group('name2')
        firstname = firstname.replace('_',' ')
        if middlename:
            middlename = middlename.replace('_',' ')
        if lastname:
            lastname = lastname.replace('_',' ')
        email = mo.group('email')
        if firstname:
            attrs['firstname'] = firstname
        if middlename:
            attrs['middlename'] = middlename
        if lastname:
            attrs['lastname'] = lastname
        if email:
            attrs['email'] = email
        return True
    def process_author_names(self):
        """ Calculate any missing author related attributes."""
        attrs = self.attributes # Alias for readability.
        firstname = attrs.get('firstname','')
        middlename = attrs.get('middlename','')
        lastname = attrs.get('lastname','')
        author = attrs.get('author')
        initials = attrs.get('authorinitials')
        if author and not (firstname or middlename or lastname):
            if not self.parse_author(author):
                return
            attrs['author'] = author.replace('_',' ')
            self.process_author_names()
            return
        if not author:
            author = '%s %s %s' % (firstname, middlename, lastname)
            author = author.strip()
            author = re.sub(r'\s+',' ', author)
        if not initials:
            initials = firstname[:1] + middlename[:1] + lastname[:1]
            initials = initials.upper()
        names = [firstname,middlename,lastname,author,initials]
        for i,v in enumerate(names):
            v = config.subs_specialchars(v)
            v = subs_attrs(v)
            names[i] = v
        firstname,middlename,lastname,author,initials = names
        if firstname:
            attrs['firstname'] = firstname
        if middlename:
            attrs['middlename'] = middlename
        if lastname:
            attrs['lastname'] = lastname
        if author:
            attrs['author'] = author
        if initials:
            attrs['authorinitials'] = initials
        if author:
            attrs['authored'] = ''


class Header:
    """Static methods and attributes only."""
    REV_LINE_RE = r'^(\D*(?P<revnumber>.*?),)?(?P<revdate>.*?)(:\s*(?P<revremark>.*))?$'
    RCS_ID_RE = r'^\$Id: \S+ (?P<revnumber>\S+) (?P<revdate>\S+) \S+ (?P<author>\S+) (\S+ )?\$$'
    def __init__(self):
        raise AssertionError,'no class instances allowed'
    @staticmethod
    def translate():
        assert Lex.next() is Title and Title.level == 0
        Title.translate()
        attrs = document.attributes # Alias for readability.
        attrs['doctitle'] = Title.attributes['title']
        if document.doctype == 'manpage':
            # manpage title formatted like mantitle(manvolnum).
            mo = re.match(r'^(?P<mantitle>.*)\((?P<manvolnum>.*)\)$',
                          attrs['doctitle'])
            if not mo:
                message.error('malformed manpage title')
            else:
                mantitle = mo.group('mantitle').strip()
                # mantitle is lowered only if in ALL CAPS
                if mantitle == mantitle.upper():
                    mantitle = mantitle.lower()
                attrs['mantitle'] = mantitle;
                attrs['manvolnum'] = mo.group('manvolnum').strip()
        AttributeEntry.translate_all()
        s = reader.read_next()
        mo = None
        if s:
            s = reader.read()
            mo = re.match(Header.RCS_ID_RE,s)
            if not mo:
                document.parse_author(s)
                AttributeEntry.translate_all()
                if reader.read_next():
                    # Parse revision line.
                    s = reader.read()
                    s = subs_attrs(s)
                    if s:
                        mo = re.match(Header.RCS_ID_RE,s)
                        if not mo:
                            mo = re.match(Header.REV_LINE_RE,s)
            AttributeEntry.translate_all()
        s = attrs.get('revnumber')
        if s:
            mo = re.match(Header.RCS_ID_RE,s)
        if mo:
            revnumber = mo.group('revnumber')
            if revnumber:
                attrs['revnumber'] = revnumber.strip()
            author = mo.groupdict().get('author')
            if author and 'firstname' not in attrs:
                document.parse_author(author)
            revremark = mo.groupdict().get('revremark')
            if revremark is not None:
                revremark = [revremark]
                # Revision remarks can continue on following lines.
                while reader.read_next() and not AttributeEntry.isnext():
                    revremark.append(reader.read())
                revremark = Lex.subs(revremark,['normal'])
                revremark = '\n'.join(revremark).strip()
                attrs['revremark'] = revremark
                AttributeEntry.translate_all()
            revdate = mo.group('revdate')
            if revdate:
                attrs['revdate'] = revdate.strip()
            elif revnumber or revremark:
                # Set revision date to ensure valid DocBook revision.
                attrs['revdate'] = attrs['docdate']
        if document.doctype == 'manpage':
            # Translate mandatory NAME section.
            if Lex.next() is not Title:
                message.error('name section expected')
            else:
                Title.translate()
                if Title.level != 1:
                    message.error('name section title must be at level 1')
                if not isinstance(Lex.next(),Paragraph):
                    message.error('malformed name section body')
                lines = reader.read_until(r'^$')
                s = ' '.join(lines)
                mo = re.match(r'^(?P<manname>.*?)\s+-\s+(?P<manpurpose>.*)$',s)
                if not mo:
                    message.error('malformed name section body')
                attrs['manname'] = mo.group('manname').strip()
                attrs['manpurpose'] = mo.group('manpurpose').strip()
                names = [s.strip() for s in attrs['manname'].split(',')]
                if len(names) > 9:
                    message.warning('to many manpage names')
                for i,name in enumerate(names):
                    attrs['manname%d' % (i+1)] = name
        document.process_author_names()

class AttributeEntry:
    """Static methods and attributes only."""
    pattern = None
    subs = None
    name = None
    name2 = None
    value = None
    def __init__(self):
        raise AssertionError,'no class instances allowed'
    @staticmethod
    def isnext():
        result = False  # Assume not next.
        if not AttributeEntry.pattern:
            pat = document.attributes.get('attributeentry-pattern')
            if not pat:
                message.error("[attributes] missing 'attributeentry-pattern' entry")
            AttributeEntry.pattern = pat
        if not AttributeEntry.subs:
            subs = document.attributes.get('attributeentry-subs')
            if subs:
                subs = parse_options(subs,SUBS_OPTIONS,
                    'illegal [%s] %s: %s' % ('attributes','attributeentry-subs',subs))
            else:
                subs = ('specialcharacters','attributes')
            AttributeEntry.subs = subs
        line = reader.read_next()
        if line:
            # Attribute entry formatted like :<name>[.<name2>]:[ <value>]
            mo = re.match(AttributeEntry.pattern,line)
            if mo:
                AttributeEntry.name = mo.group('attrname')
                AttributeEntry.name2 = mo.group('attrname2')
                AttributeEntry.value = mo.group('attrvalue') or ''
                AttributeEntry.value = AttributeEntry.value.strip()
                result = True
        return result
    @staticmethod
    def translate():
        assert Lex.next() is AttributeEntry
        attr = AttributeEntry    # Alias for brevity.
        reader.read()            # Discard attribute entry from reader.
        if AttributeEntry.name2: # The entry is a conf file entry.
            section = {}
            # Some sections can have name! syntax.
            if attr.name in ('attributes','miscellaneous') and attr.name2[-1] == '!':
                section[attr.name] = [attr.name2]
            else:
               section[attr.name] = ['%s=%s' % (attr.name2,attr.value)]
            config.load_sections(section)
            config.validate()
        else: # The entry is an attribute.
            if attr.name[-1] == '!':
                # Names like name! undefine the attribute.
                attr.name = attr.name[:-1]
                attr.value = None
            # Strip white space and illegal name chars.
            attr.name = re.sub(r'(?u)[^\w\-_]', '', attr.name).lower()
            # Don't override command-line attributes (the exception is the
            # system 'trace' attribute).
            if attr.name in config.cmd_attrs and attr.name != 'trace':
                return
            # Update document.attributes from previously parsed attribute.
            if attr.name == 'attributeentry-subs':
                AttributeEntry.subs = None  # Force update in isnext().
            elif attr.value:
                attr.value = Lex.subs((attr.value,), attr.subs)
                attr.value = writer.newline.join(attr.value)
            if attr.value is not None:
                document.attributes[attr.name] = attr.value
            elif attr.name in document.attributes:
                del document.attributes[attr.name]
    @staticmethod
    def translate_all():
        """ Process all contiguous attribute lines on reader."""
        while AttributeEntry.isnext():
            AttributeEntry.translate()

class AttributeList:
    """Static methods and attributes only."""
    pattern = None
    match = None
    attrs = {}
    def __init__(self):
        raise AssertionError,'no class instances allowed'
    @staticmethod
    def initialize():
        if not 'attributelist-pattern' in document.attributes:
            message.error("[attributes] missing 'attributelist-pattern' entry")
        AttributeList.pattern = document.attributes['attributelist-pattern']
    @staticmethod
    def isnext():
        result = False  # Assume not next.
        line = reader.read_next()
        if line:
            mo = re.match(AttributeList.pattern, line)
            if mo:
                AttributeList.match = mo
                result = True
        return result
    @staticmethod
    def translate():
        assert Lex.next() is AttributeList
        reader.read()   # Discard attribute list from reader.
        attrlist = {}
        d = AttributeList.match.groupdict()
        for k,v in d.items():
            if v is not None:
                if k == 'attrlist':
                    v = subs_attrs(v)
                    if v:
                        parse_attributes(v, attrlist)
                else:
                    AttributeList.attrs[k] = v
        # Substitute single quoted attribute values.
        reo = re.compile(r"^'.*'$")
        for k,v in attrlist.items():
            if reo.match(str(v)):
                attrlist[k] = Lex.subs_1(v[1:-1],SUBS_NORMAL)
        AttributeList.attrs.update(attrlist)
    @staticmethod
    def style():
        return AttributeList.attrs.get('style') or AttributeList.attrs.get('1')
    @staticmethod
    def consume(d):
        """Add attribute list to the dictionary 'd' and reset the
        list."""
        if AttributeList.attrs:
            d.update(AttributeList.attrs)
            AttributeList.attrs = {}
            # Generate option attributes.
            if 'options' in d:
                options = parse_options(d['options'], (), 'illegal option name')
                for option in options:
                    d[option+'-option'] = ''

class BlockTitle:
    """Static methods and attributes only."""
    title = None
    pattern = None
    def __init__(self):
        raise AssertionError,'no class instances allowed'
    @staticmethod
    def isnext():
        result = False  # Assume not next.
        line = reader.read_next()
        if line:
            mo = re.match(BlockTitle.pattern,line)
            if mo:
                BlockTitle.title = mo.group('title')
                result = True
        return result
    @staticmethod
    def translate():
        assert Lex.next() is BlockTitle
        reader.read()   # Discard title from reader.
        # Perform title substitutions.
        if not Title.subs:
            Title.subs = config.subsnormal
        s = Lex.subs((BlockTitle.title,), Title.subs)
        s = writer.newline.join(s)
        if not s:
            message.warning('blank block title')
        BlockTitle.title = s
    @staticmethod
    def consume(d):
        """If there is a title add it to dictionary 'd' then reset title."""
        if BlockTitle.title:
            d['title'] = BlockTitle.title
            BlockTitle.title = None

class Title:
    """Processes Header and Section titles. Static methods and attributes
    only."""
    # Class variables
    underlines = ('==','--','~~','^^','++') # Levels 0,1,2,3,4.
    subs = ()
    pattern = None
    level = 0
    attributes = {}
    sectname = None
    section_numbers = [0]*len(underlines)
    dump_dict = {}
    linecount = None    # Number of lines in title (1 or 2).
    def __init__(self):
        raise AssertionError,'no class instances allowed'
    @staticmethod
    def translate():
        """Parse the Title.attributes and Title.level from the reader. The
        real work has already been done by parse()."""
        assert Lex.next() is Title
        # Discard title from reader.
        for i in range(Title.linecount):
            reader.read()
        Title.setsectname()
        # Perform title substitutions.
        if not Title.subs:
            Title.subs = config.subsnormal
        s = Lex.subs((Title.attributes['title'],), Title.subs)
        s = writer.newline.join(s)
        if not s:
            message.warning('blank section title')
        Title.attributes['title'] = s
    @staticmethod
    def isnext():
        lines = reader.read_ahead(2)
        return Title.parse(lines)
    @staticmethod
    def parse(lines):
        """Parse title at start of lines tuple."""
        if len(lines) == 0: return False
        if len(lines[0]) == 0: return False # Title can't be blank.
        # Check for single-line titles.
        result = False
        for level in range(len(Title.underlines)):
            k = 'sect%s' % level
            if k in Title.dump_dict:
                mo = re.match(Title.dump_dict[k], lines[0])
                if mo:
                    Title.attributes = mo.groupdict()
                    Title.level = level
                    Title.linecount = 1
                    result = True
                    break
        if not result:
            # Check for double-line titles.
            if not Title.pattern: return False  # Single-line titles only.
            if len(lines) < 2: return False
            title,ul = lines[:2]
            title_len = char_len(title)
            ul_len = char_len(ul)
            if ul_len < 2: return False
            # Fast elimination check.
            if ul[:2] not in Title.underlines: return False
            # Length of underline must be within +-3 of title.
            if not (ul_len-3 < title_len < ul_len+3): return False
            # Check for valid repetition of underline character pairs.
            s = ul[:2]*((ul_len+1)/2)
            if ul != s[:ul_len]: return False
            # Don't be fooled by back-to-back delimited blocks, require at
            # least one alphanumeric character in title.
            if not re.search(r'(?u)\w',title): return False
            mo = re.match(Title.pattern, title)
            if mo:
                Title.attributes = mo.groupdict()
                Title.level = list(Title.underlines).index(ul[:2])
                Title.linecount = 2
                result = True
        # Check for expected pattern match groups.
        if result:
            if not 'title' in Title.attributes:
                message.warning('[titles] entry has no <title> group')
                Title.attributes['title'] = lines[0]
            for k,v in Title.attributes.items():
                if v is None: del Title.attributes[k]
        Title.attributes['level'] = str(Title.level)
        return result
    @staticmethod
    def load(entries):
        """Load and validate [titles] section entries dictionary."""
        if 'underlines' in entries:
            errmsg = 'malformed [titles] underlines entry'
            try:
                underlines = parse_list(entries['underlines'])
            except Exception:
                raise EAsciiDoc,errmsg
            if len(underlines) != len(Title.underlines):
                raise EAsciiDoc,errmsg
            for s in underlines:
                if len(s) !=2:
                    raise EAsciiDoc,errmsg
            Title.underlines = tuple(underlines)
            Title.dump_dict['underlines'] = entries['underlines']
        if 'subs' in entries:
            Title.subs = parse_options(entries['subs'], SUBS_OPTIONS,
                'illegal [titles] subs entry')
            Title.dump_dict['subs'] = entries['subs']
        if 'sectiontitle' in entries:
            pat = entries['sectiontitle']
            if not pat or not is_re(pat):
                raise EAsciiDoc,'malformed [titles] sectiontitle entry'
            Title.pattern = pat
            Title.dump_dict['sectiontitle'] = pat
        if 'blocktitle' in entries:
            pat = entries['blocktitle']
            if not pat or not is_re(pat):
                raise EAsciiDoc,'malformed [titles] blocktitle entry'
            BlockTitle.pattern = pat
            Title.dump_dict['blocktitle'] = pat
        # Load single-line title patterns.
        for k in ('sect0','sect1','sect2','sect3','sect4'):
            if k in entries:
                pat = entries[k]
                if not pat or not is_re(pat):
                    raise EAsciiDoc,'malformed [titles] %s entry' % k
                Title.dump_dict[k] = pat
        # TODO: Check we have either a Title.pattern or at least one
        # single-line title pattern -- can this be done here or do we need
        # check routine like the other block checkers?
    @staticmethod
    def dump():
        dump_section('titles',Title.dump_dict)
    @staticmethod
    def setsectname():
        """
        Set Title section name:
        If the first positional or 'template' attribute is set use it,
        next search for section title in [specialsections],
        if not found use default 'sect<level>' name.
        """
        sectname = AttributeList.attrs.get('1')
        if sectname and sectname != 'float':
            Title.sectname = sectname
        elif 'template' in AttributeList.attrs:
            Title.sectname = AttributeList.attrs['template']
        else:
            for pat,sect in config.specialsections.items():
                mo = re.match(pat,Title.attributes['title'])
                if mo:
                    title = mo.groupdict().get('title')
                    if title is not None:
                        Title.attributes['title'] = title.strip()
                    else:
                        Title.attributes['title'] = mo.group().strip()
                    Title.sectname = sect
                    break
            else:
                Title.sectname = 'sect%d' % Title.level
    @staticmethod
    def getnumber(level):
        """Return next section number at section 'level' formatted like
        1.2.3.4."""
        number = ''
        for l in range(len(Title.section_numbers)):
            n = Title.section_numbers[l]
            if l == 0:
                continue
            elif l < level:
                number = '%s%d.' % (number, n)
            elif l == level:
                number = '%s%d.' % (number, n + 1)
                Title.section_numbers[l] = n + 1
            elif l > level:
                # Reset unprocessed section levels.
                Title.section_numbers[l] = 0
        return number


class Section:
    """Static methods and attributes only."""
    endtags = []  # Stack of currently open section (level,endtag) tuples.
    ids = []      # List of already used ids.
    def __init__(self):
        raise AssertionError,'no class instances allowed'
    @staticmethod
    def savetag(level,etag):
        """Save section end."""
        Section.endtags.append((level,etag))
    @staticmethod
    def setlevel(level):
        """Set document level and write open section close tags up to level."""
        while Section.endtags and Section.endtags[-1][0] >= level:
            writer.write(Section.endtags.pop()[1],trace='section close')
        document.level = level
    @staticmethod
    def gen_id(title):
        """
        The normalized value of the id attribute is an NCName according to
        the 'Namespaces in XML' Recommendation:
        NCName          ::=     NCNameStartChar NCNameChar*
        NCNameChar      ::=     NameChar - ':'
        NCNameStartChar ::=     Letter | '_'
        NameChar        ::=     Letter | Digit | '.' | '-' | '_' | ':'
        """
        base_ident = re.sub(r'[^a-zA-Z0-9]+', '_', title).strip('_').lower()
        # Prefix the ID name with idprefix attribute or underscore if not
        # defined. Prefix ensures the ID does not clash with existing IDs.
        idprefix = document.attributes.get('idprefix','_')
        base_ident = idprefix + base_ident
        i = 1
        while True:
            if i == 1:
                ident = base_ident
            else:
                ident = '%s_%d' % (base_ident, i)
            if ident not in Section.ids:
                Section.ids.append(ident)
                return ident
            else:
                ident = base_ident
            i += 1
    @staticmethod
    def set_id():
        if not document.attributes.get('sectids') is None \
                and 'id' not in AttributeList.attrs:
            # Generate ids for sections.
            AttributeList.attrs['id'] = Section.gen_id(Title.attributes['title'])
    @staticmethod
    def translate():
        assert Lex.next() is Title
        prev_sectname = Title.sectname
        Title.translate()
        if Title.level == 0 and document.doctype != 'book':
            message.error('only book doctypes can contain level 0 sections')
        if Title.level > document.level \
                and document.backend == 'docbook' \
                and prev_sectname in ('colophon','abstract', \
                    'dedication','glossary','bibliography'):
            message.error('%s section cannot contain sub-sections' % prev_sectname)
        if Title.level > document.level+1:
            # Sub-sections of multi-part book level zero Preface and Appendices
            # are meant to be out of sequence.
            if document.doctype == 'book' \
                    and document.level == 0 \
                    and Title.level == 2 \
                    and prev_sectname in ('preface','appendix'):
                pass
            else:
                message.warning('section title out of sequence: '
                    'expected level %d, got level %d'
                    % (document.level+1, Title.level))
        Section.set_id()
        Section.setlevel(Title.level)
        Title.attributes['sectnum'] = Title.getnumber(document.level)
        AttributeList.consume(Title.attributes)
        stag,etag = config.section2tags(Title.sectname,Title.attributes)
        Section.savetag(Title.level,etag)
        writer.write(stag,trace='section open')
        Section.translate_body()
    @staticmethod
    def translate_body(terminator=Title):
        isempty = True
        next = Lex.next()
        while next and next is not terminator:
            if (isinstance(terminator,DelimitedBlock)
                and next is Title and AttributeList.style() != 'float'):
                message.error('section title not permitted in delimited block')
            next.translate()
            next = Lex.next()
            if next is Title and AttributeList.style() == 'float':
                # Process floating titles.
                template = 'floatingtitle'
                if template in config.sections:
                    Title.translate()
                    Section.set_id()
                    AttributeList.consume(Title.attributes)
                    stag,etag = config.section2tags(template,Title.attributes)
                    writer.write(stag,trace='floating title')
                    next = Lex.next()
                else:
                    message.warning('missing template section: [%s]' % template)
            isempty = False
        # The section is not empty if contains a subsection.
        if next and isempty and Title.level > document.level:
            isempty = False
        # Report empty sections if invalid markup will result.
        if isempty:
            if document.backend == 'docbook' and Title.sectname != 'index':
                message.error('empty section is not valid')

class AbstractBlock:
    def __init__(self):
        # Configuration parameter names common to all blocks.
        self.CONF_ENTRIES = ('delimiter','options','subs','presubs','postsubs',
                             'posattrs','style','.*-style','template','filter')
        self.start = None   # File reader cursor at start delimiter.
        self.name=None      # Configuration file section name.
        # Configuration parameters.
        self.delimiter=None # Regular expression matching block delimiter.
        self.delimiter_reo=None # Compiled delimiter.
        self.template=None  # template section entry.
        self.options=()     # options entry list.
        self.presubs=None   # presubs/subs entry list.
        self.postsubs=()    # postsubs entry list.
        self.filter=None    # filter entry.
        self.posattrs=()    # posattrs entry list.
        self.style=None     # Default style.
        self.styles=OrderedDict() # Each entry is a styles dictionary.
        # Before a block is processed it's attributes (from it's
        # attributes list) are merged with the block configuration parameters
        # (by self.merge_attributes()) resulting in the template substitution
        # dictionary (self.attributes) and the block's processing parameters
        # (self.parameters).
        self.attributes={}
        # The names of block parameters.
        self.PARAM_NAMES=('template','options','presubs','postsubs','filter')
        self.parameters=None
        # Leading delimiter match object.
        self.mo=None
    def short_name(self):
        """ Return the text following the last dash in the section namem """
        i = self.name.rfind('-')
        if i == -1:
            return self.name
        else:
            return self.name[i+1:]
    def error(self, msg, cursor=None, halt=False):
        message.error('[%s] %s' % (self.name,msg), cursor, halt)
    def is_conf_entry(self,param):
        """Return True if param matches an allowed configuration file entry
        name."""
        for s in self.CONF_ENTRIES:
            if re.match('^'+s+'$',param):
                return True
        return False
    def load(self,name,entries):
        """Update block definition from section 'entries' dictionary."""
        self.name = name
        self.update_parameters(entries, self, all=True)
    def update_parameters(self, src, dst=None, all=False):
        """
        Parse processing parameters from src dictionary to dst object.
        dst defaults to self.parameters.
        If all is True then copy src entries that aren't parameter names.
        """
        dst = dst or self.parameters
        msg = '[%s] malformed entry %%s: %%s' % self.name
        def copy(obj,k,v):
            if isinstance(obj,dict):
                obj[k] = v
            else:
                setattr(obj,k,v)
        for k,v in src.items():
            if not re.match(r'\d+',k) and not is_name(k):
                raise EAsciiDoc, msg % (k,v)
            if k == 'template':
                if not is_name(v):
                    raise EAsciiDoc, msg % (k,v)
                copy(dst,k,v)
            elif k == 'filter':
                copy(dst,k,v)
            elif k == 'options':
                if isinstance(v,str):
                    v = parse_options(v, (), msg % (k,v))
                copy(dst,k,v)
            elif k in ('subs','presubs','postsubs'):
                # Subs is an alias for presubs.
                if k == 'subs': k = 'presubs'
                if isinstance(v,str):
                    v = parse_options(v, SUBS_OPTIONS, msg % (k,v))
                copy(dst,k,v)
            elif k == 'delimiter':
                if v and is_re(v):
                    copy(dst,k,v)
                else:
                    raise EAsciiDoc, msg % (k,v)
            elif k == 'style':
                if is_name(v):
                    copy(dst,k,v)
                else:
                    raise EAsciiDoc, msg % (k,v)
            elif k == 'posattrs':
                v = parse_options(v, (), msg % (k,v))
                copy(dst,k,v)
            else:
                mo = re.match(r'^(?P<style>.*)-style$',k)
                if mo:
                    if not v:
                        raise EAsciiDoc, msg % (k,v)
                    style = mo.group('style')
                    if not is_name(style):
                        raise EAsciiDoc, msg % (k,v)
                    d = {}
                    if not parse_named_attributes(v,d):
                        raise EAsciiDoc, msg % (k,v)
                    if 'subs' in d:
                        # Subs is an alias for presubs.
                        d['presubs'] = d['subs']
                        del d['subs']
                    self.styles[style] = d
                elif all or k in self.PARAM_NAMES:
                    copy(dst,k,v) # Derived class specific entries.
    def get_param(self,name,params=None):
        """
        Return named processing parameter from params dictionary.
        If the parameter is not in params look in self.parameters.
        """
        if params and name in params:
            return params[name]
        elif name in self.parameters:
            return self.parameters[name]
        else:
            return None
    def get_subs(self,params=None):
        """
        Return (presubs,postsubs) tuple.
        """
        presubs = self.get_param('presubs',params)
        postsubs = self.get_param('postsubs',params)
        return (presubs,postsubs)
    def dump(self):
        """Write block definition to stdout."""
        write = lambda s: sys.stdout.write('%s%s' % (s,writer.newline))
        write('['+self.name+']')
        if self.is_conf_entry('delimiter'):
            write('delimiter='+self.delimiter)
        if self.template:
            write('template='+self.template)
        if self.options:
            write('options='+','.join(self.options))
        if self.presubs:
            if self.postsubs:
                write('presubs='+','.join(self.presubs))
            else:
                write('subs='+','.join(self.presubs))
        if self.postsubs:
            write('postsubs='+','.join(self.postsubs))
        if self.filter:
            write('filter='+self.filter)
        if self.posattrs:
            write('posattrs='+','.join(self.posattrs))
        if self.style:
            write('style='+self.style)
        if self.styles:
            for style,d in self.styles.items():
                s = ''
                for k,v in d.items(): s += '%s=%r,' % (k,v)
                write('%s-style=%s' % (style,s[:-1]))
    def validate(self):
        """Validate block after the complete configuration has been loaded."""
        if self.is_conf_entry('delimiter') and not self.delimiter:
            raise EAsciiDoc,'[%s] missing delimiter' % self.name
        if self.style:
            if not is_name(self.style):
                raise EAsciiDoc, 'illegal style name: %s' % self.style
            if not self.style in self.styles:
                if not isinstance(self,List):   # Lists don't have templates.
                    message.warning('[%s] \'%s\' style not in %s' % (
                        self.name,self.style,self.styles.keys()))
        # Check all styles for missing templates.
        all_styles_have_template = True
        for k,v in self.styles.items():
            t = v.get('template')
            if t and not t in config.sections:
                message.warning('[%s] missing template section' % t)
            if not t:
                all_styles_have_template = False
        # Check we have a valid template entry or alternatively that all the
        # styles have templates.
        if self.is_conf_entry('template') and not 'skip' in self.options:
            if self.template:
                if not self.template in config.sections:
                    message.warning('[%s] missing template section' % self.template)
            elif not all_styles_have_template:
                if not isinstance(self,List): # Lists don't have templates.
                    message.warning('[%s] styles missing templates' % self.name)
    def isnext(self):
        """Check if this block is next in document reader."""
        result = False
        reader.skip_blank_lines()
        if reader.read_next():
            if not self.delimiter_reo:
                # Cache compiled delimiter optimization.
                self.delimiter_reo = re.compile(self.delimiter)
            mo = self.delimiter_reo.match(reader.read_next())
            if mo:
                self.mo = mo
                result = True
        return result
    def translate(self):
        """Translate block from document reader."""
        if not self.presubs:
            self.presubs = config.subsnormal
        if reader.cursor:
            self.start = reader.cursor[:]
    def merge_attributes(self,attrs,params=[]):
        """
        Use the current blocks attribute list (attrs dictionary) to build a
        dictionary of block processing parameters (self.parameters) and tag
        substitution attributes (self.attributes).

        1. Copy the default parameters (self.*) to self.parameters.
        self.parameters are used internally to render the current block.
        Optional params array of addtional parameters.

        2. Copy attrs to self.attributes. self.attributes are used for template
        and tag substitution in the current block.

        3. If a style attribute was specified update self.parameters with the
        corresponding style parameters; if there are any style parameters
        remaining add them to self.attributes (existing attribute list entries
        take precedence).

        4. Set named positional attributes in self.attributes if self.posattrs
        was specified.

        5. Finally self.parameters is updated with any corresponding parameters
        specified in attrs.

        """

        def check_array_parameter(param):
            # Check the parameter is a sequence type.
            if not is_array(self.parameters[param]):
                message.error('malformed presubs attribute: %s' %
                        self.parameters[param])
                # Revert to default value.
                self.parameters[param] = getattr(self,param)

        params = list(self.PARAM_NAMES) + params
        self.attributes = {}
        if self.style:
            # If a default style is defined make it available in the template.
            self.attributes['style'] = self.style
        self.attributes.update(attrs)
        # Calculate dynamic block parameters.
        # Start with configuration file defaults.
        self.parameters = AttrDict()
        for name in params:
            self.parameters[name] = getattr(self,name)
        # Load the selected style attributes.
        posattrs = self.posattrs
        if posattrs and posattrs[0] == 'style':
            style = self.attributes.get('1')
        else:
            style = None
        if not style:
            style = self.attributes.get('style',self.style)
        if style:
            if not is_name(style):
                raise EAsciiDoc, 'illegal style name: %s' % style
            if style in self.styles:
                self.attributes['style'] = style
                for k,v in self.styles[style].items():
                    if k == 'posattrs':
                        posattrs = v
                    elif k in params:
                        self.parameters[k] = v
                    elif not k in self.attributes:
                        # Style attributes don't take precedence over explicit.
                        self.attributes[k] = v
        # Set named positional attributes.
        for i,v in enumerate(posattrs):
            if str(i+1) in self.attributes:
                self.attributes[v] = self.attributes[str(i+1)]
        # Override config and style attributes with attribute list attributes.
        self.update_parameters(attrs)
        check_array_parameter('options')
        check_array_parameter('presubs')
        check_array_parameter('postsubs')

class AbstractBlocks:
    """List of block definitions."""
    PREFIX = ''         # Conf file section name prefix set in derived classes.
    BLOCK_TYPE = None   # Block type set in derived classes.
    def __init__(self):
        self.current=None
        self.blocks = []        # List of Block objects.
        self.default = None     # Default Block.
        self.delimiters = None  # Combined delimiters regular expression.
    def load(self,sections):
        """Load block definition from 'sections' dictionary."""
        for k in sections.keys():
            if re.match(r'^'+ self.PREFIX + r'.+$',k):
                d = {}
                parse_entries(sections.get(k,()),d)
                for b in self.blocks:
                    if b.name == k:
                        break
                else:
                    b = self.BLOCK_TYPE()
                    self.blocks.append(b)
                try:
                    b.load(k,d)
                except EAsciiDoc,e:
                    raise EAsciiDoc,'[%s] %s' % (k,str(e))
    def dump(self):
        for b in self.blocks:
            b.dump()
    def isnext(self):
        for b in self.blocks:
            if b.isnext():
                self.current = b
                return True;
        return False
    def validate(self):
        """Validate the block definitions."""
        # Validate delimiters and build combined lists delimiter pattern.
        delimiters = []
        for b in self.blocks:
            assert b.__class__ is self.BLOCK_TYPE
            b.validate()
            if b.delimiter:
                delimiters.append(b.delimiter)
        self.delimiters = re_join(delimiters)

class Paragraph(AbstractBlock):
    def __init__(self):
        AbstractBlock.__init__(self)
        self.text=None          # Text in first line of paragraph.
    def load(self,name,entries):
        AbstractBlock.load(self,name,entries)
    def dump(self):
        AbstractBlock.dump(self)
        write = lambda s: sys.stdout.write('%s%s' % (s,writer.newline))
        write('')
    def isnext(self):
        result = AbstractBlock.isnext(self)
        if result:
            self.text = self.mo.groupdict().get('text')
        return result
    def translate(self):
        AbstractBlock.translate(self)
        attrs = self.mo.groupdict().copy()
        if 'text' in attrs: del attrs['text']
        BlockTitle.consume(attrs)
        AttributeList.consume(attrs)
        self.merge_attributes(attrs)
        reader.read()   # Discard (already parsed item first line).
        body = reader.read_until(paragraphs.terminators)
        body = [self.text] + list(body)
        presubs = self.parameters.presubs
        postsubs = self.parameters.postsubs
        body = Lex.set_margin(body) # Move body to left margin.
        body = Lex.subs(body,presubs)
        if self.parameters.filter:
            body = filter_lines(self.parameters.filter,body,self.attributes)
        body = Lex.subs(body,postsubs)
        template = self.parameters.template
        stag,etag = config.section2tags(template, self.attributes)
        # Write start tag, content, end tag.
        writer.write(dovetail_tags(stag,body,etag),trace='paragraph')

class Paragraphs(AbstractBlocks):
    """List of paragraph definitions."""
    BLOCK_TYPE = Paragraph
    PREFIX = 'paradef-'
    def __init__(self):
        AbstractBlocks.__init__(self)
        self.terminators=None    # List of compiled re's.
    def initialize(self):
        self.terminators = [
                re.compile(r'^\+$|^$'),
                re.compile(AttributeList.pattern),
                re.compile(blocks.delimiters),
                re.compile(tables.delimiters),
                re.compile(tables_OLD.delimiters),
            ]
    def load(self,sections):
        AbstractBlocks.load(self,sections)
    def validate(self):
        AbstractBlocks.validate(self)
        # Check we have a default paragraph definition, put it last in list.
        for b in self.blocks:
            if b.name == 'paradef-default':
                self.blocks.append(b)
                self.default = b
                self.blocks.remove(b)
                break
        else:
            raise EAsciiDoc,'missing [paradef-default] section'

class List(AbstractBlock):
    NUMBER_STYLES= ('arabic','loweralpha','upperalpha','lowerroman',
                    'upperroman')
    def __init__(self):
        AbstractBlock.__init__(self)
        self.CONF_ENTRIES += ('type','tags')
        self.PARAM_NAMES += ('tags',)
        # tabledef conf file parameters.
        self.type=None
        self.tags=None      # Name of listtags-<tags> conf section.
        # Calculated parameters.
        self.tag=None       # Current tags AttrDict.
        self.label=None     # List item label (labeled lists).
        self.text=None      # Text in first line of list item.
        self.index=None     # Matched delimiter 'index' group (numbered lists).
        self.type=None      # List type ('numbered','bulleted','labeled').
        self.ordinal=None   # Current list item ordinal number (1..)
        self.number_style=None # Current numbered list style ('arabic'..)
    def load(self,name,entries):
        AbstractBlock.load(self,name,entries)
    def dump(self):
        AbstractBlock.dump(self)
        write = lambda s: sys.stdout.write('%s%s' % (s,writer.newline))
        write('type='+self.type)
        write('tags='+self.tags)
        write('')
    def validate(self):
        AbstractBlock.validate(self)
        tags = [self.tags]
        tags += [s['tags'] for s in self.styles.values() if 'tags' in s]
        for t in tags:
            if t not in lists.tags:
                self.error('missing section: [listtags-%s]' % t,halt=True)
    def isnext(self):
        result = AbstractBlock.isnext(self)
        if result:
            self.label = self.mo.groupdict().get('label')
            self.text = self.mo.groupdict().get('text')
            self.index = self.mo.groupdict().get('index')
        return result
    def translate_entry(self):
        assert self.type == 'labeled'
        entrytag = subs_tag(self.tag.entry, self.attributes)
        labeltag = subs_tag(self.tag.label, self.attributes)
        writer.write(entrytag[0],trace='list entry open')
        writer.write(labeltag[0],trace='list label open')
        # Write labels.
        while Lex.next() is self:
            reader.read()   # Discard (already parsed item first line).
            writer.write_tag(self.tag.term, [self.label],
                             self.presubs, self.attributes,trace='list term')
            if self.text: break
        writer.write(labeltag[1],trace='list label close')
        # Write item text.
        self.translate_item()
        writer.write(entrytag[1],trace='list entry close')
    def translate_item(self):
        if self.type == 'callout':
            self.attributes['coids'] = calloutmap.calloutids(self.ordinal)
        itemtag = subs_tag(self.tag.item, self.attributes)
        writer.write(itemtag[0],trace='list item open')
        # Write ItemText.
        text = reader.read_until(lists.terminators)
        if self.text:
            text = [self.text] + list(text)
        if text:
            writer.write_tag(self.tag.text, text, self.presubs, self.attributes,trace='list text')
        # Process explicit and implicit list item continuations.
        while True:
            continuation = reader.read_next() == '+'
            if continuation: reader.read()  # Discard continuation line.
            while Lex.next() in (BlockTitle,AttributeList):
                # Consume continued element title and attributes.
                Lex.next().translate()
            if not continuation and BlockTitle.title:
                # Titled elements terminate the list.
                break
            next = Lex.next()
            if next in lists.open:
                break
            elif isinstance(next,List):
                next.translate()
            elif isinstance(next,Paragraph) and 'listelement' in next.options:
                next.translate()
            elif continuation:
                # This is where continued elements are processed.
                if next is Title:
                    message.error('section title not allowed in list item',halt=True)
                next.translate()
            else:
                break
        writer.write(itemtag[1],trace='list item close')

    @staticmethod
    def calc_style(index):
        """Return the numbered list style ('arabic'...) of the list item index.
        Return None if unrecognized style."""
        if re.match(r'^\d+[\.>]$', index):
            style = 'arabic'
        elif re.match(r'^[ivx]+\)$', index):
            style = 'lowerroman'
        elif re.match(r'^[IVX]+\)$', index):
            style = 'upperroman'
        elif re.match(r'^[a-z]\.$', index):
            style = 'loweralpha'
        elif re.match(r'^[A-Z]\.$', index):
            style = 'upperalpha'
        else:
            assert False
        return style

    @staticmethod
    def calc_index(index,style):
        """Return the ordinal number of (1...) of the list item index
        for the given list style."""
        def roman_to_int(roman):
            roman = roman.lower()
            digits = {'i':1,'v':5,'x':10}
            result = 0
            for i in range(len(roman)):
                digit = digits[roman[i]]
                # If next digit is larger this digit is negative.
                if i+1 < len(roman) and digits[roman[i+1]] > digit:
                    result -= digit
                else:
                    result += digit
            return result
        index = index[:-1]
        if style == 'arabic':
            ordinal = int(index)
        elif style == 'lowerroman':
            ordinal = roman_to_int(index)
        elif style == 'upperroman':
            ordinal = roman_to_int(index)
        elif style == 'loweralpha':
            ordinal = ord(index) - ord('a') + 1
        elif style == 'upperalpha':
            ordinal = ord(index) - ord('A') + 1
        else:
            assert False
        return ordinal

    def check_index(self):
        """Check calculated self.ordinal (1,2,...) against the item number
        in the document (self.index) and check the number style is the same as
        the first item (self.number_style)."""
        assert self.type in ('numbered','callout')
        if self.index:
            style = self.calc_style(self.index)
            if style != self.number_style:
                message.warning('list item style: expected %s got %s' %
                        (self.number_style,style), offset=1)
            ordinal = self.calc_index(self.index,style)
            if ordinal != self.ordinal:
                message.warning('list item index: expected %s got %s' %
                        (self.ordinal,ordinal), offset=1)

    def check_tags(self):
        """ Check that all necessary tags are present. """
        tags = set(Lists.TAGS)
        if self.type != 'labeled':
            tags = tags.difference(['entry','label','term'])
        missing = tags.difference(self.tag.keys())
        if missing:
            self.error('missing tag(s): %s' % ','.join(missing), halt=True)
    def translate(self):
        AbstractBlock.translate(self)
        if self.short_name() in ('bibliography','glossary','qanda'):
            message.deprecated('old %s list syntax' % self.short_name())
        lists.open.append(self)
        attrs = self.mo.groupdict().copy()
        for k in ('label','text','index'):
            if k in attrs: del attrs[k]
        if self.index:
            # Set the numbering style from first list item.
            attrs['style'] = self.calc_style(self.index)
        BlockTitle.consume(attrs)
        AttributeList.consume(attrs)
        self.merge_attributes(attrs,['tags'])
        if self.type in ('numbered','callout'):
            self.number_style = self.attributes.get('style')
            if self.number_style not in self.NUMBER_STYLES:
                message.error('illegal numbered list style: %s' % self.number_style)
                # Fall back to default style.
                self.attributes['style'] = self.number_style = self.style
        self.tag = lists.tags[self.parameters.tags]
        self.check_tags()
        if 'width' in self.attributes:
            # Set horizontal list 'labelwidth' and 'itemwidth' attributes.
            v = str(self.attributes['width'])
            mo = re.match(r'^(\d{1,2})%?$',v)
            if mo:
                labelwidth = int(mo.group(1))
                self.attributes['labelwidth'] = str(labelwidth)
                self.attributes['itemwidth'] = str(100-labelwidth)
            else:
                self.error('illegal attribute value: width="%s"' % v)
        stag,etag = subs_tag(self.tag.list, self.attributes)
        if stag:
            writer.write(stag,trace='list open')
        self.ordinal = 0
        # Process list till list syntax changes or there is a new title.
        while Lex.next() is self and not BlockTitle.title:
            self.ordinal += 1
            document.attributes['listindex'] = str(self.ordinal)
            if self.type in ('numbered','callout'):
                self.check_index()
            if self.type in ('bulleted','numbered','callout'):
                reader.read()   # Discard (already parsed item first line).
                self.translate_item()
            elif self.type == 'labeled':
                self.translate_entry()
            else:
                raise AssertionError,'illegal [%s] list type' % self.name
        if etag:
            writer.write(etag,trace='list close')
        if self.type == 'callout':
            calloutmap.validate(self.ordinal)
            calloutmap.listclose()
        lists.open.pop()
        if len(lists.open):
            document.attributes['listindex'] = str(lists.open[-1].ordinal)

class Lists(AbstractBlocks):
    """List of List objects."""
    BLOCK_TYPE = List
    PREFIX = 'listdef-'
    TYPES = ('bulleted','numbered','labeled','callout')
    TAGS = ('list', 'entry','item','text', 'label','term')
    def __init__(self):
        AbstractBlocks.__init__(self)
        self.open = []  # A stack of the current and parent lists.
        self.tags={}    # List tags dictionary. Each entry is a tags AttrDict.
        self.terminators=None    # List of compiled re's.
    def initialize(self):
        self.terminators = [
                re.compile(r'^\+$|^$'),
                re.compile(AttributeList.pattern),
                re.compile(lists.delimiters),
                re.compile(blocks.delimiters),
                re.compile(tables.delimiters),
                re.compile(tables_OLD.delimiters),
            ]
    def load(self,sections):
        AbstractBlocks.load(self,sections)
        self.load_tags(sections)
    def load_tags(self,sections):
        """
        Load listtags-* conf file sections to self.tags.
        """
        for section in sections.keys():
            mo = re.match(r'^listtags-(?P<name>\w+)$',section)
            if mo:
                name = mo.group('name')
                if name in self.tags:
                    d = self.tags[name]
                else:
                    d = AttrDict()
                parse_entries(sections.get(section,()),d)
                for k in d.keys():
                    if k not in self.TAGS:
                        message.warning('[%s] contains illegal list tag: %s' %
                                (section,k))
                self.tags[name] = d
    def validate(self):
        AbstractBlocks.validate(self)
        for b in self.blocks:
            # Check list has valid type.
            if not b.type in Lists.TYPES:
                raise EAsciiDoc,'[%s] illegal type' % b.name
            b.validate()
    def dump(self):
        AbstractBlocks.dump(self)
        for k,v in self.tags.items():
            dump_section('listtags-'+k, v)


class DelimitedBlock(AbstractBlock):
    def __init__(self):
        AbstractBlock.__init__(self)
    def load(self,name,entries):
        AbstractBlock.load(self,name,entries)
    def dump(self):
        AbstractBlock.dump(self)
        write = lambda s: sys.stdout.write('%s%s' % (s,writer.newline))
        write('')
    def isnext(self):
        return AbstractBlock.isnext(self)
    def translate(self):
        AbstractBlock.translate(self)
        reader.read()   # Discard delimiter.
        attrs = {}
        BlockTitle.consume(attrs)
        AttributeList.consume(attrs)
        self.merge_attributes(attrs)
        options = self.parameters.options
        if 'skip' in options:
            reader.read_until(self.delimiter,same_file=True)
        elif safe() and self.name == 'blockdef-backend':
            message.unsafe('Backend Block')
            reader.read_until(self.delimiter,same_file=True)
        else:
            template = self.parameters.template
            stag,etag = config.section2tags(template,self.attributes)
            name = self.short_name()+' block'
            if 'sectionbody' in options:
                # The body is treated like a section body.
                writer.write(stag,trace=name+' open')
                Section.translate_body(self)
                writer.write(etag,trace=name+' close')
            else:
                body = reader.read_until(self.delimiter,same_file=True)
                presubs = self.parameters.presubs
                postsubs = self.parameters.postsubs
                body = Lex.subs(body,presubs)
                if self.parameters.filter:
                    body = filter_lines(self.parameters.filter,body,self.attributes)
                body = Lex.subs(body,postsubs)
                # Write start tag, content, end tag.
                writer.write(dovetail_tags(stag,body,etag),trace=name)
            trace(self.short_name()+' block close',etag)
        if reader.eof():
            self.error('missing closing delimiter',self.start)
        else:
            delimiter = reader.read()   # Discard delimiter line.
            assert re.match(self.delimiter,delimiter)

class DelimitedBlocks(AbstractBlocks):
    """List of delimited blocks."""
    BLOCK_TYPE = DelimitedBlock
    PREFIX = 'blockdef-'
    def __init__(self):
        AbstractBlocks.__init__(self)
    def load(self,sections):
        """Update blocks defined in 'sections' dictionary."""
        AbstractBlocks.load(self,sections)
    def validate(self):
        AbstractBlocks.validate(self)

class Column:
    """Table column."""
    def __init__(self, width=None, align_spec=None, style=None):
        self.width = width or '1'
        self.align, self.valign = Table.parse_align_spec(align_spec)
        self.style = style      # Style name or None.
        # Calculated attribute values.
        self.abswidth = None    # 1..   (page units).
        self.pcwidth = None     # 1..99 (percentage).

class Cell:
    def __init__(self, data, span_spec=None, align_spec=None, style=None):
        self.data = data
        self.span, self.vspan = Table.parse_span_spec(span_spec)
        self.align, self.valign = Table.parse_align_spec(align_spec)
        self.style = style
    def __repr__(self):
        return '<Cell: %d.%d %s.%s %s "%s">' % (
                self.span, self.vspan,
                self.align, self.valign,
                self.style or '',
                self.data)

class Table(AbstractBlock):
    ALIGN = {'<':'left', '>':'right', '^':'center'}
    VALIGN = {'<':'top', '>':'bottom', '^':'middle'}
    FORMATS = ('psv','csv','dsv')
    SEPARATORS = dict(
        csv=',',
        dsv=r':|\n',
        # The count and align group matches are not exact.
        psv=r'((?<!\S)((?P<span>[\d.]+)(?P<op>[*+]))?(?P<align>[<\^>.]{,3})?(?P<style>[a-z])?)?\|'
    )
    def __init__(self):
        AbstractBlock.__init__(self)
        self.CONF_ENTRIES += ('format','tags','separator')
        # tabledef conf file parameters.
        self.format='psv'
        self.separator=None
        self.tags=None          # Name of tabletags-<tags> conf section.
        # Calculated parameters.
        self.abswidth=None      # 1..   (page units).
        self.pcwidth = None     # 1..99 (percentage).
        self.rows=[]            # Parsed rows, each row is a list of Cells.
        self.columns=[]         # List of Columns.
    @staticmethod
    def parse_align_spec(align_spec):
        """
        Parse AsciiDoc cell alignment specifier and return 2-tuple with
        horizonatal and vertical alignment names. Unspecified alignments
        set to None.
        """
        result = (None, None)
        if align_spec:
            mo = re.match(r'^([<\^>])?(\.([<\^>]))?$', align_spec)
            if mo:
                result = (Table.ALIGN.get(mo.group(1)),
                          Table.VALIGN.get(mo.group(3)))
        return result
    @staticmethod
    def parse_span_spec(span_spec):
        """
        Parse AsciiDoc cell span specifier and return 2-tuple with horizonatal
        and vertical span counts. Set default values (1,1) if not
        specified.
        """
        result = (None, None)
        if span_spec:
            mo = re.match(r'^(\d+)?(\.(\d+))?$', span_spec)
            if mo:
                result = (mo.group(1) and int(mo.group(1)),
                          mo.group(3) and int(mo.group(3)))
        return (result[0] or 1, result[1] or 1)
    def load(self,name,entries):
        AbstractBlock.load(self,name,entries)
    def dump(self):
        AbstractBlock.dump(self)
        write = lambda s: sys.stdout.write('%s%s' % (s,writer.newline))
        write('format='+self.format)
        write('')
    def validate(self):
        AbstractBlock.validate(self)
        if self.format not in Table.FORMATS:
            self.error('illegal format=%s' % self.format,halt=True)
        self.tags = self.tags or 'default'
        tags = [self.tags]
        tags += [s['tags'] for s in self.styles.values() if 'tags' in s]
        for t in tags:
            if t not in tables.tags:
                self.error('missing section: [tabletags-%s]' % t,halt=True)
        if self.separator:
            # Evaluate escape characters.
            self.separator = eval('"'+self.separator+'"')
        #TODO: Move to class Tables
        # Check global table parameters.
        elif config.pagewidth is None:
            self.error('missing [miscellaneous] entry: pagewidth')
        elif config.pageunits is None:
            self.error('missing [miscellaneous] entry: pageunits')
    def validate_attributes(self):
        """Validate and parse table attributes."""
        # Set defaults.
        format = self.format
        tags = self.tags
        separator = self.separator
        abswidth = float(config.pagewidth)
        pcwidth = 100.0
        for k,v in self.attributes.items():
            if k == 'format':
                if v not in self.FORMATS:
                    self.error('illegal %s=%s' % (k,v))
                else:
                    format = v
            elif k == 'tags':
                if v not in tables.tags:
                    self.error('illegal %s=%s' % (k,v))
                else:
                    tags = v
            elif k == 'separator':
                separator = v
            elif k == 'width':
                if not re.match(r'^\d{1,3}%$',v) or int(v[:-1]) > 100:
                    self.error('illegal %s=%s' % (k,v))
                else:
                    abswidth = float(v[:-1])/100 * config.pagewidth
                    pcwidth = float(v[:-1])
        # Calculate separator if it has not been specified.
        if not separator:
            separator = Table.SEPARATORS[format]
        if format == 'csv':
            if len(separator) > 1:
                self.error('illegal csv separator=%s' % separator)
                separator = ','
        else:
            if not is_re(separator):
                self.error('illegal regular expression: separator=%s' %
                        separator)
        self.parameters.format = format
        self.parameters.tags = tags
        self.parameters.separator = separator
        self.abswidth = abswidth
        self.pcwidth = pcwidth
    def get_tags(self,params):
        tags = self.get_param('tags',params)
        assert(tags and tags in tables.tags)
        return tables.tags[tags]
    def get_style(self,prefix):
        """
        Return the style dictionary whose name starts with 'prefix'.
        """
        if prefix is None:
            return None
        names = self.styles.keys()
        names.sort()
        for name in names:
            if name.startswith(prefix):
                return self.styles[name]
        else:
            self.error('missing style: %s*' % prefix)
            return None
    def parse_cols(self, cols, align, valign):
        """
        Build list of column objects from table 'cols', 'align' and 'valign'
        attributes.
        """
        # [<multiplier>*][<align>][<width>][<style>]
        COLS_RE1 = r'^((?P<count>\d+)\*)?(?P<align>[<\^>.]{,3})?(?P<width>\d+%?)?(?P<style>[a-z]\w*)?$'
        # [<multiplier>*][<width>][<align>][<style>]
        COLS_RE2 = r'^((?P<count>\d+)\*)?(?P<width>\d+%?)?(?P<align>[<\^>.]{,3})?(?P<style>[a-z]\w*)?$'
        reo1 = re.compile(COLS_RE1)
        reo2 = re.compile(COLS_RE2)
        cols = str(cols)
        if re.match(r'^\d+$',cols):
            for i in range(int(cols)):
                self.columns.append(Column())
        else:
            for col in re.split(r'\s*,\s*',cols):
                mo = reo1.match(col)
                if not mo:
                    mo = reo2.match(col)
                if mo:
                    count = int(mo.groupdict().get('count') or 1)
                    for i in range(count):
                        self.columns.append(
                            Column(mo.group('width'), mo.group('align'),
                                   self.get_style(mo.group('style')))
                        )
                else:
                    self.error('illegal column spec: %s' % col,self.start)
        # Set column (and indirectly cell) default alignments.
        for col in self.columns:
            col.align = col.align or align or 'left'
            col.valign = col.valign or valign or 'top'
        # Validate widths and calculate missing widths.
        n = 0; percents = 0; props = 0
        for col in self.columns:
            if col.width:
                if col.width[-1] == '%': percents += int(col.width[:-1])
                else: props += int(col.width)
                n += 1
        if percents > 0 and props > 0:
            self.error('mixed percent and proportional widths: %s'
                    % cols,self.start)
        pcunits = percents > 0
        # Fill in missing widths.
        if n < len(self.columns) and percents < 100:
            if pcunits:
                width = float(100 - percents)/float(len(self.columns) - n)
            else:
                width = 1
            for col in self.columns:
                if not col.width:
                    if pcunits:
                        col.width = str(int(width))+'%'
                        percents += width
                    else:
                        col.width = str(width)
                        props += width
        # Calculate column alignment and absolute and percent width values.
        percents = 0
        for col in self.columns:
            if pcunits:
                col.pcwidth = float(col.width[:-1])
            else:
                col.pcwidth = (float(col.width)/props)*100
            col.abswidth = int(self.abswidth * (col.pcwidth/100))
            percents += col.pcwidth
            col.pcwidth = int(col.pcwidth)
        if round(percents) > 100:
            self.error('total width exceeds 100%%: %s' % cols,self.start)
        elif round(percents) < 100:
            self.error('total width less than 100%%: %s' % cols,self.start)
    def build_colspecs(self):
        """
        Generate column related substitution attributes.
        """
        cols = []
        i = 1
        for col in self.columns:
            colspec = self.get_tags(col.style).colspec
            if colspec:
                self.attributes['align'] = col.align
                self.attributes['valign'] = col.valign
                self.attributes['colabswidth'] = col.abswidth
                self.attributes['colpcwidth'] = col.pcwidth
                self.attributes['colnumber'] = str(i)
                s = subs_attrs(colspec, self.attributes)
                if not s:
                    message.warning('colspec dropped: contains undefined attribute')
                else:
                    cols.append(s)
            i += 1
        if cols:
            self.attributes['colspecs'] = writer.newline.join(cols)
    def parse_rows(self, text):
        """
        Parse the table source text into self.rows (a list of rows, each row
        is a list of Cells.
        """
        reserved = {}  # Cols reserved by rowspans (indexed by row number).
        if self.parameters.format in ('psv','dsv'):
            ri = 0  # Current row index 0..
            cells = self.parse_psv_dsv(text)
            row = []
            ci = 0  # Column counter 0..colcount
            for cell in cells:
                colcount = len(self.columns) - reserved.get(ri,0)
                if cell.vspan > 1:
                    # Reserve spanned columns from ensuing rows.
                    for i in range(1, cell.vspan):
                        reserved[ri+i] = reserved.get(ri+i, 0) + cell.span
                ci += cell.span
                if ci <= colcount:
                    row.append(cell)
                if ci >= colcount:
                    self.rows.append(row)
                    ri += 1
                    row = []
                    ci = 0
                if ci > colcount:
                    message.warning('table row %d: span exceeds number of columns'
                            % ri)
        elif self.parameters.format == 'csv':
            self.rows = self.parse_csv(text)
        else:
            assert True,'illegal table format'
        # Check that all row spans match.
        for ri,row in enumerate(self.rows):
            row_span = 0
            for cell in row:
                row_span += cell.span
            row_span += reserved.get(ri,0)
            if ri == 0:
                header_span = row_span
            if row_span < header_span:
                message.warning('table row %d: does not span all columns' % (ri+1))
            if row_span > header_span:
                message.warning('table row %d: exceeds columns span' % (ri+1))
        # Check that now row spans exceed the number of rows.
        if len([x for x in reserved.keys() if x >= len(self.rows)]) > 0:
            message.warning('one or more cell spans exceed the available rows')
    def subs_rows(self, rows, rowtype='body'):
        """
        Return a string of output markup from a list of rows, each row
        is a list of raw data text.
        """
        tags = tables.tags[self.parameters.tags]
        if rowtype == 'header':
            rtag = tags.headrow
        elif rowtype == 'footer':
            rtag = tags.footrow
        else:
            rtag = tags.bodyrow
        result = []
        stag,etag = subs_tag(rtag,self.attributes)
        for row in rows:
            result.append(stag)
            result += self.subs_row(row,rowtype)
            result.append(etag)
        return writer.newline.join(result)
    def subs_row(self, row, rowtype):
        """
        Substitute the list of Cells using the data tag.
        Returns a list of marked up table cell elements.
        """
        result = []
        i = 0
        for cell in row:
            col = self.columns[i]
            self.attributes['align'] = cell.align or col.align
            self.attributes['valign'] = cell.valign or  col.valign
            self.attributes['colabswidth'] = col.abswidth
            self.attributes['colpcwidth'] = col.pcwidth
            self.attributes['colnumber'] = str(i+1)
            self.attributes['colspan'] = str(cell.span)
            self.attributes['colstart'] = self.attributes['colnumber']
            self.attributes['colend'] = str(i+cell.span)
            self.attributes['rowspan'] = str(cell.vspan)
            self.attributes['morerows'] = str(cell.vspan-1)
            # Fill missing column data with blanks.
            if i > len(self.columns) - 1:
                data = ''
            else:
                data = cell.data
            if rowtype == 'header':
                # Use table style unless overriden by cell style.
                colstyle = cell.style
            else:
                # If the cell style is not defined use the column style.
                colstyle = cell.style or col.style
            tags = self.get_tags(colstyle)
            presubs,postsubs = self.get_subs(colstyle)
            data = [data]
            data = Lex.subs(data, presubs)
            data = filter_lines(self.get_param('filter',colstyle),
                                data, self.attributes)
            data = Lex.subs(data, postsubs)
            if rowtype != 'header':
                ptag = tags.paragraph
                if ptag:
                    stag,etag = subs_tag(ptag,self.attributes)
                    text = '\n'.join(data).strip()
                    data = []
                    for para in re.split(r'\n{2,}',text):
                        data += dovetail_tags([stag],para.split('\n'),[etag])
            if rowtype == 'header':
                dtag = tags.headdata
            elif rowtype == 'footer':
                dtag = tags.footdata
            else:
                dtag = tags.bodydata
            stag,etag = subs_tag(dtag,self.attributes)
            result = result + dovetail_tags([stag],data,[etag])
            i += cell.span
        return result
    def parse_csv(self,text):
        """
        Parse the table source text and return a list of rows, each row
        is a list of Cells.
        """
        import StringIO
        import csv
        rows = []
        rdr = csv.reader(StringIO.StringIO('\r\n'.join(text)),
                     delimiter=self.parameters.separator, skipinitialspace=True)
        try:
            for row in rdr:
                rows.append([Cell(data) for data in row])
        except Exception:
            self.error('csv parse error: %s' % row)
        return rows
    def parse_psv_dsv(self,text):
        """
        Parse list of PSV or DSV table source text lines and return a list of
        Cells.
        """
        def append_cell(data, span_spec, op, align_spec, style):
            op = op or '+'
            if op == '*':   # Cell multiplier.
                span = Table.parse_span_spec(span_spec)[0]
                for i in range(span):
                    cells.append(Cell(data, '1', align_spec, style))
            elif op == '+': # Column spanner.
                cells.append(Cell(data, span_spec, align_spec, style))
            else:
                self.error('illegal table cell operator')
        text = '\n'.join(text)
        separator = '(?msu)'+self.parameters.separator
        format = self.parameters.format
        start = 0
        span = None
        op = None
        align = None
        style = None
        cells = []
        data = ''
        for mo in re.finditer(separator,text):
            data += text[start:mo.start()]
            if data.endswith('\\'):
                data = data[:-1]+mo.group() # Reinstate escaped separators.
            else:
                append_cell(data, span, op, align, style)
                span = mo.groupdict().get('span')
                op = mo.groupdict().get('op')
                align = mo.groupdict().get('align')
                style = mo.groupdict().get('style')
                if style:
                    style = self.get_style(style)
                data = ''
            start = mo.end()
        # Last cell follows final separator.
        data += text[start:]
        append_cell(data, span, op, align, style)
        # We expect a dummy blank item preceeding first PSV cell.
        if format == 'psv':
            if cells[0].data.strip() != '':
                self.error('missing leading separator: %s' % separator,
                        self.start)
            else:
                cells.pop(0)
        return cells
    def translate(self):
        AbstractBlock.translate(self)
        reader.read()   # Discard delimiter.
        # Reset instance specific properties.
        self.columns = []
        self.rows = []
        attrs = {}
        BlockTitle.consume(attrs)
        # Mix in document attribute list.
        AttributeList.consume(attrs)
        self.merge_attributes(attrs)
        self.validate_attributes()
        # Add global and calculated configuration parameters.
        self.attributes['pagewidth'] = config.pagewidth
        self.attributes['pageunits'] = config.pageunits
        self.attributes['tableabswidth'] = int(self.abswidth)
        self.attributes['tablepcwidth'] = int(self.pcwidth)
        # Read the entire table.
        text = reader.read_until(self.delimiter)
        if reader.eof():
            self.error('missing closing delimiter',self.start)
        else:
            delimiter = reader.read()   # Discard closing delimiter.
            assert re.match(self.delimiter,delimiter)
        if len(text) == 0:
            message.warning('[%s] table is empty' % self.name)
            return
        cols = attrs.get('cols')
        if not cols:
            # Calculate column count from number of items in first line.
            if self.parameters.format == 'csv':
                cols = text[0].count(self.parameters.separator)
            else:
                cols = 0
                for cell in self.parse_psv_dsv(text[:1]):
                    cols += cell.span
        self.parse_cols(cols, attrs.get('align'), attrs.get('valign'))
        # Set calculated attributes.
        self.attributes['colcount'] = len(self.columns)
        self.build_colspecs()
        self.parse_rows(text)
        # The 'rowcount' attribute is used by the experimental LaTeX backend.
        self.attributes['rowcount'] = str(len(self.rows))
        # Generate headrows, footrows, bodyrows.
        # Headrow, footrow and bodyrow data replaces same named attributes in
        # the table markup template. In order to ensure this data does not get
        # a second attribute substitution (which would interfere with any
        # already substituted inline passthroughs) unique placeholders are used
        # (the tab character does not appear elsewhere since it is expanded on
        # input) which are replaced after template attribute substitution.
        headrows = footrows = bodyrows = None
        if self.rows and 'header' in self.parameters.options:
            headrows = self.subs_rows(self.rows[0:1],'header')
            self.attributes['headrows'] = '\x07headrows\x07'
            self.rows = self.rows[1:]
        if self.rows and 'footer' in self.parameters.options:
            footrows = self.subs_rows( self.rows[-1:], 'footer')
            self.attributes['footrows'] = '\x07footrows\x07'
            self.rows = self.rows[:-1]
        if self.rows:
            bodyrows = self.subs_rows(self.rows)
            self.attributes['bodyrows'] = '\x07bodyrows\x07'
        table = subs_attrs(config.sections[self.parameters.template],
                           self.attributes)
        table = writer.newline.join(table)
        # Before we finish replace the table head, foot and body place holders
        # with the real data.
        if headrows:
            table = table.replace('\x07headrows\x07', headrows, 1)
        if footrows:
            table = table.replace('\x07footrows\x07', footrows, 1)
        if bodyrows:
            table = table.replace('\x07bodyrows\x07', bodyrows, 1)
        writer.write(table,trace='table')

class Tables(AbstractBlocks):
    """List of tables."""
    BLOCK_TYPE = Table
    PREFIX = 'tabledef-'
    TAGS = ('colspec', 'headrow','footrow','bodyrow',
            'headdata','footdata', 'bodydata','paragraph')
    def __init__(self):
        AbstractBlocks.__init__(self)
        # Table tags dictionary. Each entry is a tags dictionary.
        self.tags={}
    def load(self,sections):
        AbstractBlocks.load(self,sections)
        self.load_tags(sections)
    def load_tags(self,sections):
        """
        Load tabletags-* conf file sections to self.tags.
        """
        for section in sections.keys():
            mo = re.match(r'^tabletags-(?P<name>\w+)$',section)
            if mo:
                name = mo.group('name')
                if name in self.tags:
                    d = self.tags[name]
                else:
                    d = AttrDict()
                parse_entries(sections.get(section,()),d)
                for k in d.keys():
                    if k not in self.TAGS:
                        message.warning('[%s] contains illegal table tag: %s' %
                                (section,k))
                self.tags[name] = d
    def validate(self):
        AbstractBlocks.validate(self)
        # Check we have a default table definition,
        for i in range(len(self.blocks)):
            if self.blocks[i].name == 'tabledef-default':
                default = self.blocks[i]
                break
        else:
            raise EAsciiDoc,'missing [tabledef-default] section'
        # Propagate defaults to unspecified table parameters.
        for b in self.blocks:
            if b is not default:
                if b.format is None: b.format = default.format
                if b.template is None: b.template = default.template
        # Check tags and propagate default tags.
        if not 'default' in self.tags:
            raise EAsciiDoc,'missing [tabletags-default] section'
        default = self.tags['default']
        for tag in ('bodyrow','bodydata','paragraph'): # Mandatory default tags.
            if tag not in default:
                raise EAsciiDoc,'missing [tabletags-default] entry: %s' % tag
        for t in self.tags.values():
            if t is not default:
                if t.colspec is None: t.colspec = default.colspec
                if t.headrow is None: t.headrow = default.headrow
                if t.footrow is None: t.footrow = default.footrow
                if t.bodyrow is None: t.bodyrow = default.bodyrow
                if t.headdata is None: t.headdata = default.headdata
                if t.footdata is None: t.footdata = default.footdata
                if t.bodydata is None: t.bodydata = default.bodydata
                if t.paragraph is None: t.paragraph = default.paragraph
        # Use body tags if header and footer tags are not specified.
        for t in self.tags.values():
            if not t.headrow: t.headrow = t.bodyrow
            if not t.footrow: t.footrow = t.bodyrow
            if not t.headdata: t.headdata = t.bodydata
            if not t.footdata: t.footdata = t.bodydata
        # Check table definitions are valid.
        for b in self.blocks:
            b.validate()
    def dump(self):
        AbstractBlocks.dump(self)
        for k,v in self.tags.items():
            dump_section('tabletags-'+k, v)

class Macros:
    # Default system macro syntax.
    SYS_RE = r'(?u)^(?P<name>[\\]?\w(\w|-)*?)::(?P<target>\S*?)' + \
             r'(\[(?P<attrlist>.*?)\])$'
    def __init__(self):
        self.macros = []        # List of Macros.
        self.current = None     # The last matched block macro.
        self.passthroughs = []
        # Initialize default system macro.
        m = Macro()
        m.pattern = self.SYS_RE
        m.prefix = '+'
        m.reo = re.compile(m.pattern)
        self.macros.append(m)
    def load(self,entries):
        for entry in entries:
            m = Macro()
            m.load(entry)
            if m.name is None:
                # Delete undefined macro.
                for i,m2 in enumerate(self.macros):
                    if m2.pattern == m.pattern:
                        del self.macros[i]
                        break
                else:
                    message.warning('unable to delete missing macro: %s' % m.pattern)
            else:
                # Check for duplicates.
                for m2 in self.macros:
                    if m2.pattern == m.pattern:
                        message.verbose('macro redefinition: %s%s' % (m.prefix,m.name))
                        break
                else:
                    self.macros.append(m)
    def dump(self):
        write = lambda s: sys.stdout.write('%s%s' % (s,writer.newline))
        write('[macros]')
        # Dump all macros except the first (built-in system) macro.
        for m in self.macros[1:]:
            # Escape = in pattern.
            macro = '%s=%s%s' % (m.pattern.replace('=',r'\='), m.prefix, m.name)
            if m.subslist is not None:
                macro += '[' + ','.join(m.subslist) + ']'
            write(macro)
        write('')
    def validate(self):
        # Check all named sections exist.
        if config.verbose:
            for m in self.macros:
                if m.name and m.prefix != '+':
                    m.section_name()
    def subs(self,text,prefix='',callouts=False):
        # If callouts is True then only callout macros are processed, if False
        # then all non-callout macros are processed.
        result = text
        for m in self.macros:
            if m.prefix == prefix:
                if callouts ^ (m.name != 'callout'):
                    result = m.subs(result)
        return result
    def isnext(self):
        """Return matching macro if block macro is next on reader."""
        reader.skip_blank_lines()
        line = reader.read_next()
        if line:
            for m in self.macros:
                if m.prefix == '#':
                    if m.reo.match(line):
                        self.current = m
                        return m
        return False
    def match(self,prefix,name,text):
        """Return re match object matching 'text' with macro type 'prefix',
        macro name 'name'."""
        for m in self.macros:
            if m.prefix == prefix:
                mo = m.reo.match(text)
                if mo:
                    if m.name == name:
                        return mo
                    if re.match(name,mo.group('name')):
                        return mo
        return None
    def extract_passthroughs(self,text,prefix=''):
        """ Extract the passthrough text and replace with temporary
        placeholders."""
        self.passthroughs = []
        for m in self.macros:
            if m.has_passthrough() and m.prefix == prefix:
                text = m.subs_passthroughs(text, self.passthroughs)
        return text
    def restore_passthroughs(self,text):
        """ Replace passthough placeholders with the original passthrough
        text."""
        for i,v in enumerate(self.passthroughs):
            text = text.replace('\x07'+str(i)+'\x07', self.passthroughs[i], 1)
        return text

class Macro:
    def __init__(self):
        self.pattern = None     # Matching regular expression.
        self.name = ''          # Conf file macro name (None if implicit).
        self.prefix = ''        # '' if inline, '+' if system, '#' if block.
        self.reo = None         # Compiled pattern re object.
        self.subslist = []      # Default subs for macros passtext group.
    def has_passthrough(self):
        return self.pattern.find(r'(?P<passtext>') >= 0
    def section_name(self,name=None):
        """Return macro markup template section name based on macro name and
        prefix.  Return None section not found."""
        assert self.prefix != '+'
        if not name:
            assert self.name
            name = self.name
        if self.prefix == '#':
            suffix = '-blockmacro'
        else:
            suffix = '-inlinemacro'
        if name+suffix in config.sections:
            return name+suffix
        else:
            message.warning('missing macro section: [%s]' % (name+suffix))
            return None
    def load(self,entry):
        e = parse_entry(entry)
        if e is None:
            # Only the macro pattern was specified, mark for deletion.
            self.name = None
            self.pattern = entry
            return
        if not is_re(e[0]):
            raise EAsciiDoc,'illegal macro regular expression: %s' % e[0]
        pattern, name = e
        if name and name[0] in ('+','#'):
            prefix, name = name[0], name[1:]
        else:
            prefix = ''
        # Parse passthrough subslist.
        mo = re.match(r'^(?P<name>[^[]*)(\[(?P<subslist>.*)\])?$', name)
        name = mo.group('name')
        if name and not is_name(name):
            raise EAsciiDoc,'illegal section name in macro entry: %s' % entry
        subslist = mo.group('subslist')
        if subslist is not None:
            # Parse and validate passthrough subs.
            subslist = parse_options(subslist, SUBS_OPTIONS,
                                 'illegal subs in macro entry: %s' % entry)
        self.pattern = pattern
        self.reo = re.compile(pattern)
        self.prefix = prefix
        self.name = name
        self.subslist = subslist or []

    def subs(self,text):
        def subs_func(mo):
            """Function called to perform inline macro substitution.
            Uses matched macro regular expression object and returns string
            containing the substituted macro body."""
            # Check if macro reference is escaped.
            if mo.group()[0] == '\\':
                return mo.group()[1:]   # Strip leading backslash.
            d = mo.groupdict()
            # Delete groups that didn't participate in match.
            for k,v in d.items():
                if v is None: del d[k]
            if self.name:
                name = self.name
            else:
                if not 'name' in d:
                    message.warning('missing macro name group: %s' % mo.re.pattern)
                    return ''
                name = d['name']
            section_name = self.section_name(name)
            if not section_name:
                return ''
            # If we're dealing with a block macro get optional block ID and
            # block title.
            if self.prefix == '#':
                AttributeList.consume(d)
                BlockTitle.consume(d)
            # Parse macro attributes.
            if 'attrlist' in d:
                if d['attrlist'] in (None,''):
                    del d['attrlist']
                else:
                    if self.prefix == '':
                        # Unescape ] characters in inline macros.
                        d['attrlist'] = d['attrlist'].replace('\\]',']')
                    parse_attributes(d['attrlist'],d)
                    # Generate option attributes.
                    if 'options' in d:
                        options = parse_options(d['options'], (),
                                '%s: illegal option name' % name)
                        for option in options:
                            d[option+'-option'] = ''
            if name == 'callout':
                listindex =int(d['index'])
                d['coid'] = calloutmap.add(listindex)
            # Unescape special characters in LaTeX target file names.
            if document.backend == 'latex' and 'target' in d and d['target']:
                if not '0' in d:
                    d['0'] = d['target']
                d['target']= config.subs_specialchars_reverse(d['target'])
            # BUG: We've already done attribute substitution on the macro which
            # means that any escaped attribute references are now unescaped and
            # will be substituted by config.subs_section() below. As a partial
            # fix have withheld {0} from substitution but this kludge doesn't
            # fix it for other attributes containing unescaped references.
            # Passthrough macros don't have this problem.
            a0 = d.get('0')
            if a0:
                d['0'] = chr(0)  # Replace temporarily with unused character.
            body = config.subs_section(section_name,d)
            if len(body) == 0:
                result = ''
            elif len(body) == 1:
                result = body[0]
            else:
                if self.prefix == '#':
                    result = writer.newline.join(body)
                else:
                    # Internally processed inline macros use UNIX line
                    # separator.
                    result = '\n'.join(body)
            if a0:
                result = result.replace(chr(0), a0)
            return result

        return self.reo.sub(subs_func, text)

    def translate(self):
        """ Block macro translation."""
        assert self.prefix == '#'
        s = reader.read()
        before = s
        if self.has_passthrough():
            s = macros.extract_passthroughs(s,'#')
        s = subs_attrs(s)
        if s:
            s = self.subs(s)
            if self.has_passthrough():
                s = macros.restore_passthroughs(s)
            if s:
                trace('macro',before,s)
                writer.write(s)

    def subs_passthroughs(self, text, passthroughs):
        """ Replace macro attribute lists in text with placeholders.
        Substitute and append the passthrough attribute lists to the
        passthroughs list."""
        def subs_func(mo):
            """Function called to perform inline macro substitution.
            Uses matched macro regular expression object and returns string
            containing the substituted macro body."""
            # Don't process escaped macro references.
            if mo.group()[0] == '\\':
                return mo.group()
            d = mo.groupdict()
            if not 'passtext' in d:
                message.warning('passthrough macro %s: missing passtext group' %
                        d.get('name',''))
                return mo.group()
            passtext = d['passtext']
            if re.search('\x07\\d+\x07', passtext):
                message.warning('nested inline passthrough')
                return mo.group()
            if d.get('subslist'):
                if d['subslist'].startswith(':'):
                    message.error('block macro cannot occur here: %s' % mo.group(),
                          halt=True)
                subslist = parse_options(d['subslist'], SUBS_OPTIONS,
                          'illegal passthrough macro subs option')
            else:
                subslist = self.subslist
            passtext = Lex.subs_1(passtext,subslist)
            if passtext is None: passtext = ''
            if self.prefix == '':
                # Unescape ] characters in inline macros.
                passtext = passtext.replace('\\]',']')
            passthroughs.append(passtext)
            # Tabs guarantee the placeholders are unambiguous.
            result = (
                text[mo.start():mo.start('passtext')] +
                '\x07' + str(len(passthroughs)-1) + '\x07' +
                text[mo.end('passtext'):mo.end()]
            )
            return result

        return self.reo.sub(subs_func, text)


class CalloutMap:
    def __init__(self):
        self.comap = {}         # key = list index, value = callouts list.
        self.calloutindex = 0   # Current callout index number.
        self.listnumber = 1     # Current callout list number.
    def listclose(self):
        # Called when callout list is closed.
        self.listnumber += 1
        self.calloutindex = 0
        self.comap = {}
    def add(self,listindex):
        # Add next callout index to listindex map entry. Return the callout id.
        self.calloutindex += 1
        # Append the coindex to a list in the comap dictionary.
        if not listindex in self.comap:
            self.comap[listindex] = [self.calloutindex]
        else:
            self.comap[listindex].append(self.calloutindex)
        return self.calloutid(self.listnumber, self.calloutindex)
    @staticmethod
    def calloutid(listnumber,calloutindex):
        return 'CO%d-%d' % (listnumber,calloutindex)
    def calloutids(self,listindex):
        # Retieve list of callout indexes that refer to listindex.
        if listindex in self.comap:
            result = ''
            for coindex in self.comap[listindex]:
                result += ' ' + self.calloutid(self.listnumber,coindex)
            return result.strip()
        else:
            message.warning('no callouts refer to list item '+str(listindex))
            return ''
    def validate(self,maxlistindex):
        # Check that all list indexes referenced by callouts exist.
        for listindex in self.comap.keys():
            if listindex > maxlistindex:
                message.warning('callout refers to non-existent list item '
                        + str(listindex))

#---------------------------------------------------------------------------
# Input stream Reader and output stream writer classes.
#---------------------------------------------------------------------------

class Reader1:
    """Line oriented AsciiDoc input file reader. Processes include and
    conditional inclusion system macros. Tabs are expanded and lines are right
    trimmed."""
    # This class is not used directly, use Reader class instead.
    READ_BUFFER_MIN = 10        # Read buffer low level.
    def __init__(self):
        self.f = None           # Input file object.
        self.fname = None       # Input file name.
        self.next = []          # Read ahead buffer containing
                                # [filename,linenumber,linetext] lists.
        self.cursor = None      # Last read() [filename,linenumber,linetext].
        self.tabsize = 8        # Tab expansion number of spaces.
        self.parent = None      # Included reader's parent reader.
        self._lineno = 0        # The last line read from file object f.
        self.current_depth = 0  # Current include depth.
        self.max_depth = 5      # Initial maxiumum allowed include depth.
    def open(self,fname):
        self.fname = fname
        message.verbose('reading: '+fname)
        if fname == '<stdin>':
            self.f = sys.stdin
            document.attributes['infile'] = None
            document.attributes['indir'] = None
        else:
            self.f = open(fname,'rb')
            document.attributes['infile'] = fname
            document.attributes['indir'] = os.path.dirname(fname)
        self._lineno = 0            # The last line read from file object f.
        self.next = []
        # Prefill buffer by reading the first line and then pushing it back.
        if Reader1.read(self):
            self.unread(self.cursor)
            self.cursor = None
    def closefile(self):
        """Used by class methods to close nested include files."""
        self.f.close()
        self.next = []
    def close(self):
        self.closefile()
        self.__init__()
    def read(self, skip=False):
        """Read next line. Return None if EOF. Expand tabs. Strip trailing
        white space. Maintain self.next read ahead buffer. If skip=True then
        conditional exclusion is active (ifdef and ifndef macros)."""
        # Top up buffer.
        if len(self.next) <= self.READ_BUFFER_MIN:
            s = self.f.readline()
            if s:
                self._lineno = self._lineno + 1
            while s:
                if self.tabsize != 0:
                    s = s.expandtabs(self.tabsize)
                s = s.rstrip()
                self.next.append([self.fname,self._lineno,s])
                if len(self.next) > self.READ_BUFFER_MIN:
                    break
                s = self.f.readline()
                if s:
                    self._lineno = self._lineno + 1
        # Return first (oldest) buffer entry.
        if len(self.next) > 0:
            self.cursor = self.next[0]
            del self.next[0]
            result = self.cursor[2]
            # Check for include macro.
            mo = macros.match('+',r'include[1]?',result)
            if mo and not skip:
                # Don't process include macro once the maximum depth is reached.
                if self.current_depth >= self.max_depth:
                    return result
                # Perform attribute substitution on include macro file name.
                fname = subs_attrs(mo.group('target'))
                if not fname:
                    return Reader1.read(self)   # Return next input line.
                if self.fname != '<stdin>':
                    fname = os.path.expandvars(os.path.expanduser(fname))
                    fname = safe_filename(fname, os.path.dirname(self.fname))
                    if not fname:
                        return Reader1.read(self)   # Return next input line.
                    if mo.group('name') == 'include1':
                        if not config.dumping:
                            # Store the include file in memory for later
                            # retrieval by the {include1:} system attribute.
                            config.include1[fname] = [
                                s.rstrip() for s in open(fname)]
                            return '{include1:%s}' % fname
                        else:
                            # This is a configuration dump, just pass the macro
                            # call through.
                            return result
                # Parse include macro attributes.
                attrs = {}
                parse_attributes(mo.group('attrlist'),attrs)
                # Clone self and set as parent (self assumes the role of child).
                parent = Reader1()
                assign(parent,self)
                self.parent = parent
                # Set attributes in child.
                if 'tabsize' in attrs:
                    self.tabsize = int(validate(attrs['tabsize'],
                        'int($)>=0',
                        'illegal include macro tabsize argument'))
                else:
                    self.tabsize = config.tabsize
                if 'depth' in attrs:
                    attrs['depth'] = int(validate(attrs['depth'],
                        'int($)>=1',
                        'illegal include macro depth argument'))
                    self.max_depth = self.current_depth + attrs['depth']
                # Process included file.
                self.open(fname)
                self.current_depth = self.current_depth + 1
                result = Reader1.read(self)
        else:
            if not Reader1.eof(self):
                result = Reader1.read(self)
            else:
                result = None
        return result
    def eof(self):
        """Returns True if all lines have been read."""
        if len(self.next) == 0:
            # End of current file.
            if self.parent:
                self.closefile()
                assign(self,self.parent)    # Restore parent reader.
                return Reader1.eof(self)
            else:
                return True
        else:
            return False
    def read_next(self):
        """Like read() but does not advance file pointer."""
        if Reader1.eof(self):
            return None
        else:
            return self.next[0][2]
    def unread(self,cursor):
        """Push the line (filename,linenumber,linetext) tuple back into the read
        buffer. Note that it's up to the caller to restore the previous
        cursor."""
        assert cursor
        self.next.insert(0,cursor)

class Reader(Reader1):
    """ Wraps (well, sought of) Reader1 class and implements conditional text
    inclusion."""
    def __init__(self):
        Reader1.__init__(self)
        self.depth = 0          # if nesting depth.
        self.skip = False       # true if we're skipping ifdef...endif.
        self.skipname = ''      # Name of current endif macro target.
        self.skipto = -1        # The depth at which skipping is reenabled.
    def read_super(self):
        result = Reader1.read(self,self.skip)
        if result is None and self.skip:
            raise EAsciiDoc,'missing endif::%s[]' % self.skipname
        return result
    def read(self):
        result = self.read_super()
        if result is None:
            return None
        while self.skip:
            mo = macros.match('+',r'ifdef|ifndef|endif',result)
            if mo:
                name = mo.group('name')
                target = mo.group('target')
                if name == 'endif':
                    self.depth = self.depth-1
                    if self.depth < 0:
                        raise EAsciiDoc,'mismatched macro: %s' % result
                    if self.depth == self.skipto:
                        self.skip = False
                        if target and self.skipname != target:
                            raise EAsciiDoc,'mismatched macro: %s' % result
                else:   # ifdef or ifndef.
                    if not target:
                        raise EAsciiDoc,'missing macro target: %s' % result
                    attrlist = mo.group('attrlist')
                    if not attrlist:
                        self.depth = self.depth+1
            result = self.read_super()
            if result is None:
                return None
        mo = macros.match('+',r'ifdef|ifndef|endif',result)
        if mo:
            name = mo.group('name')
            target = mo.group('target')
            if name == 'endif':
                self.depth = self.depth-1
            else:   # ifdef or ifndef.
                if not target:
                    raise EAsciiDoc,'missing macro target: %s' % result
                defined = document.attributes.get(target) is not None
                attrlist = mo.group('attrlist')
                if name == 'ifdef':
                    if attrlist:
                        if defined: return attrlist
                    else:
                        self.skip = not defined
                else:   # ifndef.
                    if attrlist:
                        if not defined: return attrlist
                    else:
                        self.skip = defined
                if not attrlist:
                    if self.skip:
                        self.skipto = self.depth
                        self.skipname = target
                    self.depth = self.depth+1
            result = self.read()
        if result:
            # Expand executable block macros.
            mo = macros.match('+',r'eval|sys|sys2',result)
            if mo:
                action = mo.group('name')
                cmd = mo.group('attrlist')
                s = system(action, cmd, is_macro=True)
                if s is not None:
                    self.cursor[2] = s  # So we don't re-evaluate.
                    result = s
        if result:
            # Unescape escaped system macros.
            if macros.match('+',r'\\eval|\\sys|\\sys2|\\ifdef|\\ifndef|\\endif|\\include|\\include1',result):
                result = result[1:]
        return result
    def eof(self):
        return self.read_next() is None
    def read_next(self):
        save_cursor = self.cursor
        result = self.read()
        if result is not None:
            self.unread(self.cursor)
            self.cursor = save_cursor
        return result
    def read_lines(self,count=1):
        """Return tuple containing count lines."""
        result = []
        i = 0
        while i < count and not self.eof():
            result.append(self.read())
        return tuple(result)
    def read_ahead(self,count=1):
        """Same as read_lines() but does not advance the file pointer."""
        result = []
        putback = []
        save_cursor = self.cursor
        try:
            i = 0
            while i < count and not self.eof():
                result.append(self.read())
                putback.append(self.cursor)
                i = i+1
            while putback:
                self.unread(putback.pop())
        finally:
            self.cursor = save_cursor
        return tuple(result)
    def skip_blank_lines(self):
        reader.read_until(r'\s*\S+')
    def read_until(self,terminators,same_file=False):
        """Like read() but reads lines up to (but not including) the first line
        that matches the terminator regular expression, regular expression
        object or list of regular expression objects. If same_file is True then
        the terminating pattern must occur in the file the was being read when
        the routine was called."""
        if same_file:
            fname = self.cursor[0]
        result = []
        if not isinstance(terminators,list):
            if isinstance(terminators,basestring):
                terminators = [re.compile(terminators)]
            else:
                terminators = [terminators]
        while not self.eof():
            save_cursor = self.cursor
            s = self.read()
            if not same_file or fname == self.cursor[0]:
                for reo in terminators:
                    if reo.match(s):
                        self.unread(self.cursor)
                        self.cursor = save_cursor
                        return tuple(result)
            result.append(s)
        return tuple(result)
    # NOT USED -- part of unimplemented attempt a generalised line continuation.
    def read_continuation(self):
        """Like read() but treats trailing backslash as line continuation
        character."""
        s = self.read()
        if s is None:
            return None
        result = ''
        while s is not None and len(s) > 0 and s[-1] == '\\':
            result = result + s[:-1]
            s = self.read()
        if s is not None:
            result = result + s
        return result
    # NOT USED -- part of unimplemented attempt a generalised line continuation.
    def read_next_continuation(self):
        """Like read_next() but treats trailing backslash as line continuation
        character."""
        save_cursor = self.cursor
        result = self.read_continuation()
        if result is not None:
            self.unread(self.cursor)
            self.cursor = save_cursor
        return result

class Writer:
    """Writes lines to output file."""
    def __init__(self):
        self.newline = '\r\n'            # End of line terminator.
        self.f = None                    # Output file object.
        self.fname = None                # Output file name.
        self.lines_out = 0               # Number of lines written.
        self.skip_blank_lines = False    # If True don't output blank lines.
    def open(self,fname):
        self.fname = fname
        if fname == '<stdout>':
            self.f = sys.stdout
        else:
            self.f = open(fname,'wb+')
        self.lines_out = 0
    def close(self):
        if self.fname != '<stdout>':
            self.f.close()
    def write_line(self, line=None):
        if not (self.skip_blank_lines and (not line or not line.strip())):
            self.f.write((line or '') + self.newline)
            self.lines_out = self.lines_out + 1
    def write(self,*args,**kwargs):
        """Iterates arguments, writes tuple and list arguments one line per
        element, else writes argument as single line. If no arguments writes
        blank line. If argument is None nothing is written. self.newline is
        appended to each line."""
        if 'trace' in kwargs and len(args) > 0:
            trace(kwargs['trace'],args[0])
        if len(args) == 0:
            self.write_line()
            self.lines_out = self.lines_out + 1
        else:
            for arg in args:
                if is_array(arg):
                    for s in arg:
                        self.write_line(s)
                elif arg is not None:
                    self.write_line(arg)
    def write_tag(self,tag,content,subs=None,d=None,**kwargs):
        """Write content enveloped by tag.
        Substitutions specified in the 'subs' list are perform on the
        'content'."""
        if subs is None:
            subs = config.subsnormal
        stag,etag = subs_tag(tag,d)
        content = Lex.subs(content,subs)
        if 'trace' in kwargs:
            trace(kwargs['trace'],[stag]+content+[etag])
        if stag:
            self.write(stag)
        if content:
            self.write(content)
        if etag:
            self.write(etag)

#---------------------------------------------------------------------------
# Configuration file processing.
#---------------------------------------------------------------------------
def _subs_specialwords(mo):
    """Special word substitution function called by
    Config.subs_specialwords()."""
    word = mo.re.pattern                    # The special word.
    template = config.specialwords[word]    # The corresponding markup template.
    if not template in config.sections:
        raise EAsciiDoc,'missing special word template [%s]' % template
    if mo.group()[0] == '\\':
        return mo.group()[1:]   # Return escaped word.
    args = {}
    args['words'] = mo.group()  # The full match string is argument 'words'.
    args.update(mo.groupdict()) # Add other named match groups to the arguments.
    # Delete groups that didn't participate in match.
    for k,v in args.items():
        if v is None: del args[k]
    lines = subs_attrs(config.sections[template],args)
    if len(lines) == 0:
        result = ''
    elif len(lines) == 1:
        result = lines[0]
    else:
        result = writer.newline.join(lines)
    return result

class Config:
    """Methods to process configuration files."""
    # Non-template section name regexp's.
    ENTRIES_SECTIONS= ('tags','miscellaneous','attributes','specialcharacters',
            'specialwords','macros','replacements','quotes','titles',
            r'paradef-.+',r'listdef-.+',r'blockdef-.+',r'tabledef-.+',
            r'tabletags-.+',r'listtags-.+','replacements2',
            r'old_tabledef-.+')
    def __init__(self):
        self.sections = OrderedDict()   # Keyed by section name containing
                                        # lists of section lines.
        # Command-line options.
        self.verbose = False
        self.header_footer = True       # -s, --no-header-footer option.
        # [miscellaneous] section.
        self.tabsize = 8
        self.textwidth = 70             # DEPRECATED: Old tables only.
        self.newline = '\r\n'
        self.pagewidth = None
        self.pageunits = None
        self.outfilesuffix = ''
        self.subsnormal = SUBS_NORMAL
        self.subsverbatim = SUBS_VERBATIM

        self.tags = {}          # Values contain (stag,etag) tuples.
        self.specialchars = {}  # Values of special character substitutions.
        self.specialwords = {}  # Name is special word pattern, value is macro.
        self.replacements = OrderedDict()   # Key is find pattern, value is
                                            #replace pattern.
        self.replacements2 = OrderedDict()
        self.specialsections = {} # Name is special section name pattern, value
                                  # is corresponding section name.
        self.quotes = OrderedDict()    # Values contain corresponding tag name.
        self.fname = ''         # Most recently loaded configuration file name.
        self.conf_attrs = {}    # Attributes entries from conf files.
        self.cmd_attrs = {}     # Attributes from command-line -a options.
        self.loaded = []        # Loaded conf files.
        self.include1 = {}      # Holds include1::[] files for {include1:}.
        self.dumping = False    # True if asciidoc -c option specified.

    def load_file(self,fname,dir=None):
        """
        Loads sections dictionary with sections from file fname.
        Existing sections are overlaid.
        Return False if no file was found in any of the locations.
        """
        if dir:
            fname = os.path.join(dir, fname)
        # Sliently skip missing configuration file.
        if not os.path.isfile(fname):
            return False
        # Don't load conf files twice (local and application conf files are the
        # same if the source file is in the application directory).
        if os.path.realpath(fname) in self.loaded:
            return True
        rdr = Reader()  # Reader processes system macros.
        rdr.open(fname)
        self.fname = fname
        reo = re.compile(r'(?u)^\[(?P<section>[^\W\d][\w-]*)\]\s*$')
        sections = OrderedDict()
        section,contents = '',[]
        while not rdr.eof():
            s = rdr.read()
            if s and s[0] == '#':       # Skip comment lines.
                continue
            if s[:2] == '\\#':          # Unescape lines starting with '#'.
                s = s[1:]
            s = s.rstrip()
            found = reo.findall(s)
            if found:
                if section:             # Store previous section.
                    if section in sections \
                        and self.entries_section(section):
                        if ''.join(contents):
                            # Merge entries.
                            sections[section] = sections[section] + contents
                        else:
                            del sections[section]
                    else:
                        sections[section] = contents
                section = found[0].lower()
                contents = []
            else:
                contents.append(s)
        if section and contents:        # Store last section.
            if section in sections \
                and self.entries_section(section):
                if ''.join(contents):
                    # Merge entries.
                    sections[section] = sections[section] + contents
                else:
                    del sections[section]
            else:
                sections[section] = contents
        rdr.close()
        self.load_sections(sections)
        self.loaded.append(os.path.realpath(fname))
        document.update_attributes() # So they are available immediately.
        return True

    def load_sections(self,sections):
        '''Loads sections dictionary. Each dictionary entry contains a
        list of lines.
        '''
        # Delete trailing blank lines from sections.
        for k in sections.keys():
            for i in range(len(sections[k])-1,-1,-1):
                if not sections[k][i]:
                    del sections[k][i]
                elif not self.entries_section(k):
                    break
        # Add/overwrite new sections.
        self.sections.update(sections)
        self.parse_tags()
        # Internally [miscellaneous] section entries are just attributes.
        d = {}
        parse_entries(sections.get('miscellaneous',()), d, unquote=True,
                allow_name_only=True)
        update_attrs(self.conf_attrs,d)
        d = {}
        parse_entries(sections.get('attributes',()), d, unquote=True,
                allow_name_only=True)
        update_attrs(self.conf_attrs,d)
        d = {}
        parse_entries(sections.get('titles',()),d)
        Title.load(d)
        parse_entries(sections.get('specialcharacters',()),self.specialchars,escape_delimiter=False)
        parse_entries(sections.get('quotes',()),self.quotes)
        self.parse_specialwords()
        self.parse_replacements()
        self.parse_replacements('replacements2')
        self.parse_specialsections()
        paragraphs.load(sections)
        lists.load(sections)
        blocks.load(sections)
        tables_OLD.load(sections)
        tables.load(sections)
        macros.load(sections.get('macros',()))

    def get_load_dirs(self):
        """Return list of well known paths to search for conf files."""
        result = []
        # Load global configuration from system configuration directory.
        result.append(CONF_DIR)
        # Load global configuration files from asciidoc directory.
        result.append(APP_DIR)
        # Load configuration files from ~/.asciidoc if it exists.
        if USER_DIR is not None:
            result.append(USER_DIR)
        # Load configuration files from document directory.
        if document.infile != '<stdin>':
            result.append(os.path.dirname(document.infile))
        return result

    def load_lang(self, lang, dirs=None):
        """
        Load language conf file from dirs list.
        If dirs not specified try all the well known locations.
        Return False if no file was found in any of the locations.
        """
        result = False
        if dirs is None:
            dirs = self.get_load_dirs()
        filename = 'lang-' + lang + '.conf'
        for d in dirs:
            if self.load_file(filename,d):
                result = True
        return result

    def load_all(self, dirs=None):
        """
        Load the standard configuration (except the language file)
        files from dirs list.
        If dirs not specified try all the well known locations.
        """
        if dirs is None:
            dirs = self.get_load_dirs()
        for d in dirs:
            self.load_file('asciidoc.conf',d)
            conf = document.backend + '.conf'
            self.load_file(conf,d)
            conf = document.backend + '-' + document.doctype + '.conf'
            self.load_file(conf,d)
            # Load filter .conf files.
            filtersdir = os.path.join(d,'filters')
            for dirpath,dirnames,filenames in os.walk(filtersdir):
                for f in filenames:
                    if re.match(r'^.+\.conf$',f):
                        self.load_file(f,dirpath)
            # English defaults.
            self.load_file('lang-en.conf',d)

    def load_miscellaneous(self,d):
        """Set miscellaneous configuration entries from dictionary 'd'."""
        def set_misc(name,rule='True',intval=False):
            if name in d:
                errmsg = 'illegal [miscellaneous] %s entry' % name
                if intval:
                    setattr(self, name, int(validate(d[name],rule,errmsg)))
                else:
                    setattr(self, name, validate(d[name],rule,errmsg))
        set_misc('tabsize','int($)>0',intval=True)
        set_misc('textwidth','int($)>0',intval=True) # DEPRECATED: Old tables only.
        set_misc('pagewidth','int($)>0',intval=True)
        set_misc('pageunits')
        set_misc('outfilesuffix')
        if 'newline' in d:
            # Convert escape sequences to their character values.
            self.newline = eval('"'+d['newline']+'"')
        if 'subsnormal' in d:
            self.subsnormal = parse_options(d['subsnormal'],SUBS_OPTIONS,
                    'illegal [%s] %s: %s' %
                    ('miscellaneous','subsnormal',d['subsnormal']))
        if 'subsverbatim' in d:
            self.subsverbatim = parse_options(d['subsverbatim'],SUBS_OPTIONS,
                    'illegal [%s] %s: %s' %
                    ('miscellaneous','subsverbatim',d['subsverbatim']))

    def validate(self):
        """Check the configuration for internal consistancy. Called after all
        configuration files have been loaded."""
        # Heuristic validate that at least one configuration file was loaded.
        if not self.specialchars or not self.tags or not lists:
            raise EAsciiDoc,'incomplete configuration files'
        # Check special characters are only one character long.
        for k in self.specialchars.keys():
            if len(k) != 1:
                raise EAsciiDoc,'[specialcharacters] ' \
                                'must be a single character: %s' % k
        # Check all special words have a corresponding inline macro body.
        for macro in self.specialwords.values():
            if not is_name(macro):
                raise EAsciiDoc,'illegal special word name: %s' % macro
            if not macro in self.sections:
                message.warning('missing special word macro: [%s]' % macro)
        # Check all text quotes have a corresponding tag.
        for q in self.quotes.keys():
            tag = self.quotes[q]
            if not tag:
                del self.quotes[q]  # Undefine quote.
            else:
                if tag[0] == '#':
                    tag = tag[1:]
                if not tag in self.tags:
                    message.warning('[quotes] %s missing tag definition: %s' % (q,tag))
        # Check all specialsections section names exist.
        for k,v in self.specialsections.items():
            if not v:
                del self.specialsections[k]
            elif not v in self.sections:
                message.warning('[%s] missing specialsections section' % v)
        paragraphs.validate()
        lists.validate()
        blocks.validate()
        tables_OLD.validate()
        tables.validate()
        macros.validate()

    def entries_section(self,section_name):
        """
        Return True if conf file section contains entries, not a markup
        template.
        """
        for name in self.ENTRIES_SECTIONS:
            if re.match(name,section_name):
                return True
        return False

    def dump(self):
        """Dump configuration to stdout."""
        # Header.
        hdr = ''
        hdr = hdr + '#' + writer.newline
        hdr = hdr + '# Generated by AsciiDoc %s for %s %s.%s' % \
            (VERSION,document.backend,document.doctype,writer.newline)
        t = time.asctime(time.localtime(time.time()))
        hdr = hdr + '# %s%s' % (t,writer.newline)
        hdr = hdr + '#' + writer.newline
        sys.stdout.write(hdr)
        # Dump special sections.
        # Dump only the configuration file and command-line attributes.
        # [miscellanous] entries are dumped as part of the [attributes].
        d = {}
        d.update(self.conf_attrs)
        d.update(self.cmd_attrs)
        dump_section('attributes',d)
        Title.dump()
        dump_section('quotes',self.quotes)
        dump_section('specialcharacters',self.specialchars)
        d = {}
        for k,v in self.specialwords.items():
            if v in d:
                d[v] = '%s "%s"' % (d[v],k)   # Append word list.
            else:
                d[v] = '"%s"' % k
        dump_section('specialwords',d)
        dump_section('replacements',self.replacements)
        dump_section('replacements2',self.replacements2)
        dump_section('specialsections',self.specialsections)
        d = {}
        for k,v in self.tags.items():
            d[k] = '%s|%s' % v
        dump_section('tags',d)
        paragraphs.dump()
        lists.dump()
        blocks.dump()
        tables_OLD.dump()
        tables.dump()
        macros.dump()
        # Dump remaining sections.
        for k in self.sections.keys():
            if not self.entries_section(k):
                sys.stdout.write('[%s]%s' % (k,writer.newline))
                for line in self.sections[k]:
                    sys.stdout.write('%s%s' % (line,writer.newline))
                sys.stdout.write(writer.newline)

    def subs_section(self,section,d):
        """Section attribute substitution using attributes from
        document.attributes and 'd'.  Lines containing undefinded
        attributes are deleted."""
        if section in self.sections:
            return subs_attrs(self.sections[section],d)
        else:
            message.warning('missing [%s] section' % section)
            return ()

    def parse_tags(self):
        """Parse [tags] section entries into self.tags dictionary."""
        d = {}
        parse_entries(self.sections.get('tags',()),d)
        for k,v in d.items():
            if v is None:
                if k in self.tags:
                    del self.tags[k]
            elif v == '':
                self.tags[k] = (None,None)
            else:
                mo = re.match(r'(?P<stag>.*)\|(?P<etag>.*)',v)
                if mo:
                    self.tags[k] = (mo.group('stag'), mo.group('etag'))
                else:
                    raise EAsciiDoc,'[tag] %s value malformed' % k

    def tag(self, name, d=None):
        """Returns (starttag,endtag) tuple named name from configuration file
        [tags] section. Raise error if not found. If a dictionary 'd' is
        passed then merge with document attributes and perform attribute
        substitution on tags."""

        # TODO: Tags should be stored a single string, not split into start
        # and end tags since most are going to be substituted anyway (see
        # subs_tag() for how we should process them. parse_tags() (above)
        # should only validate i.e. parse_check(). This routine should be renamed
        # split_tag() and would call subs_tag(). self.tags dictionary values
        # would be strings not tuples.

        if not name in self.tags:
            raise EAsciiDoc, 'missing tag: %s' % name
        stag,etag = self.tags[name]
        if d is not None:
            # TODO: Should we warn if substitution drops a tag?
            if stag:
                stag = subs_attrs(stag,d)
            if etag:
                etag = subs_attrs(etag,d)
        if stag is None: stag = ''
        if etag is None: etag = ''
        return (stag,etag)

    def parse_specialsections(self):
        """Parse specialsections section to self.specialsections dictionary."""
        # TODO: This is virtually the same as parse_replacements() and should
        # be factored to single routine.
        d = {}
        parse_entries(self.sections.get('specialsections',()),d,unquote=True)
        for pat,sectname in d.items():
            pat = strip_quotes(pat)
            if not is_re(pat):
                raise EAsciiDoc,'[specialsections] entry ' \
                                'is not a valid regular expression: %s' % pat
            if sectname is None:
                if pat in self.specialsections:
                    del self.specialsections[pat]
            else:
                self.specialsections[pat] = sectname

    def parse_replacements(self,sect='replacements'):
        """Parse replacements section into self.replacements dictionary."""
        d = OrderedDict()
        parse_entries(self.sections.get(sect,()), d, unquote=True)
        for pat,rep in d.items():
            if not self.set_replacement(pat, rep, getattr(self,sect)):
                raise EAsciiDoc,'[%s] entry in %s is not a valid' \
                    ' regular expression: %s' % (sect,self.fname,pat)

    @staticmethod
    def set_replacement(pat, rep, replacements):
        """Add pattern and replacement to replacements dictionary."""
        pat = strip_quotes(pat)
        if not is_re(pat):
            return False
        if rep is None:
            if pat in replacements:
                del replacements[pat]
        else:
            replacements[pat] = strip_quotes(rep)
        return True

    def subs_replacements(self,s,sect='replacements'):
        """Substitute patterns from self.replacements in 's'."""
        result = s
        for pat,rep in getattr(self,sect).items():
            result = re.sub(pat, rep, result)
        return result

    def parse_specialwords(self):
        """Parse special words section into self.specialwords dictionary."""
        reo = re.compile(r'(?:\s|^)(".+?"|[^"\s]+)(?=\s|$)')
        for line in self.sections.get('specialwords',()):
            e = parse_entry(line)
            if not e:
                raise EAsciiDoc,'[specialwords] entry in %s is malformed: %s' \
                    % (self.fname,line)
            name,wordlist = e
            if not is_name(name):
                raise EAsciiDoc,'[specialwords] name in %s is illegal: %s' \
                    % (self.fname,name)
            if wordlist is None:
                # Undefine all words associated with 'name'.
                for k,v in self.specialwords.items():
                    if v == name:
                        del self.specialwords[k]
            else:
                words = reo.findall(wordlist)
                for word in words:
                    word = strip_quotes(word)
                    if not is_re(word):
                        raise EAsciiDoc,'[specialwords] entry in %s ' \
                            'is not a valid regular expression: %s' \
                            % (self.fname,word)
                    self.specialwords[word] = name

    def subs_specialchars(self,s):
        """Perform special character substitution on string 's'."""
        """It may seem like a good idea to escape special characters with a '\'
        character, the reason we don't is because the escape character itself
        then has to be escaped and this makes including code listings
        problematic. Use the predefined {amp},{lt},{gt} attributes instead."""
        result = ''
        for ch in s:
            result = result + self.specialchars.get(ch,ch)
        return result

    def subs_specialchars_reverse(self,s):
        """Perform reverse special character substitution on string 's'."""
        result = s
        for k,v in self.specialchars.items():
            result = result.replace(v, k)
        return result

    def subs_specialwords(self,s):
        """Search for word patterns from self.specialwords in 's' and
        substitute using corresponding macro."""
        result = s
        for word in self.specialwords.keys():
            result = re.sub(word, _subs_specialwords, result)
        return result

    def expand_templates(self,entries):
        """Expand any template::[] macros in a list of section entries."""
        result = []
        for line in entries:
            mo = macros.match('+',r'template',line)
            if mo:
                s = mo.group('attrlist')
                if s in self.sections:
                    result += self.expand_templates(self.sections[s])
                else:
                    message.warning('missing [%s] section' % s)
            else:
                result.append(line)
        return result

    def expand_all_templates(self):
        for k,v in self.sections.items():
            self.sections[k] = self.expand_templates(v)

    def section2tags(self, section, d={}):
        """Perform attribute substitution on 'section' using document
        attributes plus 'd' attributes. Return tuple (stag,etag) containing
        pre and post | placeholder tags."""
        assert section is not None
        if section in self.sections:
            body = self.sections[section]
        else:
            message.warning('missing [%s] section' % section)
            body = ()
        # Split macro body into start and end tag lists.
        stag = []
        etag = []
        in_stag = True
        for s in body:
            if in_stag:
                mo = re.match(r'(?P<stag>.*)\|(?P<etag>.*)',s)
                if mo:
                    if mo.group('stag'):
                        stag.append(mo.group('stag'))
                    if mo.group('etag'):
                        etag.append(mo.group('etag'))
                    in_stag = False
                else:
                    stag.append(s)
            else:
                etag.append(s)
        # Do attribute substitution last so {brkbar} can be used to escape |.
        # But don't do attribute substitution on title -- we've already done it.
        title = d.get('title')
        if title:
            d['title'] = chr(0)  # Replace with unused character.
        stag = subs_attrs(stag, d)
        etag = subs_attrs(etag, d)
        # Put the {title} back.
        if title:
            stag = map(lambda x: x.replace(chr(0), title), stag)
            etag = map(lambda x: x.replace(chr(0), title), etag)
            d['title'] = title
        return (stag,etag)


#---------------------------------------------------------------------------
# Deprecated old table classes follow.
# Naming convention is an _OLD name suffix.
# These will be removed from future versions of AsciiDoc
#

def join_lines_OLD(lines):
    """Return a list in which lines terminated with the backslash line
    continuation character are joined."""
    result = []
    s = ''
    continuation = False
    for line in lines:
        if line and line[-1] == '\\':
            s = s + line[:-1]
            continuation = True
            continue
        if continuation:
            result.append(s+line)
            s = ''
            continuation = False
        else:
            result.append(line)
    if continuation:
        result.append(s)
    return result

class Column_OLD:
    """Table column."""
    def __init__(self):
        self.colalign = None    # 'left','right','center'
        self.rulerwidth = None
        self.colwidth = None    # Output width in page units.

class Table_OLD(AbstractBlock):
    COL_STOP = r"(`|'|\.)"  # RE.
    ALIGNMENTS = {'`':'left', "'":'right', '.':'center'}
    FORMATS = ('fixed','csv','dsv')
    def __init__(self):
        AbstractBlock.__init__(self)
        self.CONF_ENTRIES += ('template','fillchar','format','colspec',
                              'headrow','footrow','bodyrow','headdata',
                              'footdata', 'bodydata')
        # Configuration parameters.
        self.fillchar=None
        self.format=None    # 'fixed','csv','dsv'
        self.colspec=None
        self.headrow=None
        self.footrow=None
        self.bodyrow=None
        self.headdata=None
        self.footdata=None
        self.bodydata=None
        # Calculated parameters.
        self.underline=None     # RE matching current table underline.
        self.isnumeric=False    # True if numeric ruler.
        self.tablewidth=None    # Optional table width scale factor.
        self.columns=[]         # List of Columns.
        # Other.
        self.check_msg=''       # Message set by previous self.validate() call.
    def load(self,name,entries):
        AbstractBlock.load(self,name,entries)
        """Update table definition from section entries in 'entries'."""
        for k,v in entries.items():
            if k == 'fillchar':
                if v and len(v) == 1:
                    self.fillchar = v
                else:
                    raise EAsciiDoc,'malformed table fillchar: %s' % v
            elif k == 'format':
                if v in Table_OLD.FORMATS:
                    self.format = v
                else:
                    raise EAsciiDoc,'illegal table format: %s' % v
            elif k == 'colspec':
                self.colspec = v
            elif k == 'headrow':
                self.headrow = v
            elif k == 'footrow':
                self.footrow = v
            elif k == 'bodyrow':
                self.bodyrow = v
            elif k == 'headdata':
                self.headdata = v
            elif k == 'footdata':
                self.footdata = v
            elif k == 'bodydata':
                self.bodydata = v
    def dump(self):
        AbstractBlock.dump(self)
        write = lambda s: sys.stdout.write('%s%s' % (s,writer.newline))
        write('fillchar='+self.fillchar)
        write('format='+self.format)
        if self.colspec:
            write('colspec='+self.colspec)
        if self.headrow:
            write('headrow='+self.headrow)
        if self.footrow:
            write('footrow='+self.footrow)
        write('bodyrow='+self.bodyrow)
        if self.headdata:
            write('headdata='+self.headdata)
        if self.footdata:
            write('footdata='+self.footdata)
        write('bodydata='+self.bodydata)
        write('')
    def validate(self):
        AbstractBlock.validate(self)
        """Check table definition and set self.check_msg if invalid else set
        self.check_msg to blank string."""
        # Check global table parameters.
        if config.textwidth is None:
            self.check_msg = 'missing [miscellaneous] textwidth entry'
        elif config.pagewidth is None:
            self.check_msg = 'missing [miscellaneous] pagewidth entry'
        elif config.pageunits is None:
            self.check_msg = 'missing [miscellaneous] pageunits entry'
        elif self.headrow is None:
            self.check_msg = 'missing headrow entry'
        elif self.footrow is None:
            self.check_msg = 'missing footrow entry'
        elif self.bodyrow is None:
            self.check_msg = 'missing bodyrow entry'
        elif self.headdata is None:
            self.check_msg = 'missing headdata entry'
        elif self.footdata is None:
            self.check_msg = 'missing footdata entry'
        elif self.bodydata is None:
            self.check_msg = 'missing bodydata entry'
        else:
            # No errors.
            self.check_msg = ''
    def isnext(self):
        return AbstractBlock.isnext(self)
    def parse_ruler(self,ruler):
        """Parse ruler calculating underline and ruler column widths."""
        fc = re.escape(self.fillchar)
        # Strip and save optional tablewidth from end of ruler.
        mo = re.match(r'^(.*'+fc+r'+)([\d\.]+)$',ruler)
        if mo:
            ruler = mo.group(1)
            self.tablewidth = float(mo.group(2))
            self.attributes['tablewidth'] = str(float(self.tablewidth))
        else:
            self.tablewidth = None
            self.attributes['tablewidth'] = '100.0'
        # Guess whether column widths are specified numerically or not.
        if ruler[1] != self.fillchar:
            # If the first column does not start with a fillchar then numeric.
            self.isnumeric = True
        elif ruler[1:] == self.fillchar*len(ruler[1:]):
            # The case of one column followed by fillchars is numeric.
            self.isnumeric = True
        else:
            self.isnumeric = False
        # Underlines must be 3 or more fillchars.
        self.underline = r'^' + fc + r'{3,}$'
        splits = re.split(self.COL_STOP,ruler)[1:]
        # Build self.columns.
        for i in range(0,len(splits),2):
            c = Column_OLD()
            c.colalign = self.ALIGNMENTS[splits[i]]
            s = splits[i+1]
            if self.isnumeric:
                # Strip trailing fillchars.
                s = re.sub(fc+r'+$','',s)
                if s == '':
                    c.rulerwidth = None
                else:
                    c.rulerwidth = int(validate(s,'int($)>0',
                        'malformed ruler: bad width'))
            else:   # Calculate column width from inter-fillchar intervals.
                if not re.match(r'^'+fc+r'+$',s):
                    raise EAsciiDoc,'malformed ruler: illegal fillchars'
                c.rulerwidth = len(s)+1
            self.columns.append(c)
        # Fill in unspecified ruler widths.
        if self.isnumeric:
            if self.columns[0].rulerwidth is None:
                prevwidth = 1
            for c in self.columns:
                if c.rulerwidth is None:
                    c.rulerwidth = prevwidth
                prevwidth = c.rulerwidth
    def build_colspecs(self):
        """Generate colwidths and colspecs. This can only be done after the
        table arguments have been parsed since we use the table format."""
        self.attributes['cols'] = len(self.columns)
        # Calculate total ruler width.
        totalwidth = 0
        for c in self.columns:
            totalwidth = totalwidth + c.rulerwidth
        if totalwidth <= 0:
            raise EAsciiDoc,'zero width table'
        # Calculate marked up colwidths from rulerwidths.
        for c in self.columns:
            # Convert ruler width to output page width.
            width = float(c.rulerwidth)
            if self.format == 'fixed':
                if self.tablewidth is None:
                    # Size proportional to ruler width.
                    colfraction = width/config.textwidth
                else:
                    # Size proportional to page width.
                    colfraction = width/totalwidth
            else:
                    # Size proportional to page width.
                colfraction = width/totalwidth
            c.colwidth = colfraction * config.pagewidth # To page units.
            if self.tablewidth is not None:
                c.colwidth = c.colwidth * self.tablewidth   # Scale factor.
                if self.tablewidth > 1:
                    c.colwidth = c.colwidth/100 # tablewidth is in percent.
        # Build colspecs.
        if self.colspec:
            cols = []
            i = 0
            for c in self.columns:
                i += 1
                self.attributes['colalign'] = c.colalign
                self.attributes['colwidth'] = str(int(c.colwidth))
                self.attributes['colnumber'] = str(i + 1)
                s = subs_attrs(self.colspec,self.attributes)
                if not s:
                    message.warning('colspec dropped: contains undefined attribute')
                else:
                    cols.append(s)
            self.attributes['colspecs'] = writer.newline.join(cols)
    def split_rows(self,rows):
        """Return a two item tuple containing a list of lines up to but not
        including the next underline (continued lines are joined ) and the
        tuple of all lines after the underline."""
        reo = re.compile(self.underline)
        i = 0
        while not reo.match(rows[i]):
            i = i+1
        if i == 0:
            raise EAsciiDoc,'missing table rows'
        if i >= len(rows):
            raise EAsciiDoc,'closing [%s] underline expected' % self.name
        return (join_lines_OLD(rows[:i]), rows[i+1:])
    def parse_rows(self, rows, rtag, dtag):
        """Parse rows list using the row and data tags. Returns a substituted
        list of output lines."""
        result = []
        # Source rows are parsed as single block, rather than line by line, to
        # allow the CSV reader to handle multi-line rows.
        if self.format == 'fixed':
            rows = self.parse_fixed(rows)
        elif self.format == 'csv':
            rows = self.parse_csv(rows)
        elif self.format == 'dsv':
            rows = self.parse_dsv(rows)
        else:
            assert True,'illegal table format'
        # Substitute and indent all data in all rows.
        stag,etag = subs_tag(rtag,self.attributes)
        for row in rows:
            result.append('  '+stag)
            for data in self.subs_row(row,dtag):
                result.append('    '+data)
            result.append('  '+etag)
        return result
    def subs_row(self, data, dtag):
        """Substitute the list of source row data elements using the data tag.
        Returns a substituted list of output table data items."""
        result = []
        if len(data) < len(self.columns):
            message.warning('fewer row data items then table columns')
        if len(data) > len(self.columns):
            message.warning('more row data items than table columns')
        for i in range(len(self.columns)):
            if i > len(data) - 1:
                d = ''  # Fill missing column data with blanks.
            else:
                d = data[i]
            c = self.columns[i]
            self.attributes['colalign'] = c.colalign
            self.attributes['colwidth'] = str(int(c.colwidth))
            self.attributes['colnumber'] = str(i + 1)
            stag,etag = subs_tag(dtag,self.attributes)
            # Insert AsciiDoc line break (' +') where row data has newlines
            # ('\n').  This is really only useful when the table format is csv
            # and the output markup is HTML. It's also a bit dubious in that it
            # assumes the user has not modified the shipped line break pattern.
            subs = self.get_subs()[0]
            if 'replacements' in subs:
                # Insert line breaks in cell data.
                d = re.sub(r'(?m)\n',r' +\n',d)
                d = d.split('\n')    # So writer.newline is written.
            else:
                d = [d]
            result = result + [stag] + Lex.subs(d,subs) + [etag]
        return result
    def parse_fixed(self,rows):
        """Parse the list of source table rows. Each row item in the returned
        list contains a list of cell data elements."""
        result = []
        for row in rows:
            data = []
            start = 0
            # build an encoded representation
            row = char_decode(row)
            for c in self.columns:
                end = start + c.rulerwidth
                if c is self.columns[-1]:
                    # Text in last column can continue forever.
                    # Use the encoded string to slice, but convert back
                    # to plain string before further processing
                    data.append(char_encode(row[start:]).strip())
                else:
                    data.append(char_encode(row[start:end]).strip())
                start = end
            result.append(data)
        return result
    def parse_csv(self,rows):
        """Parse the list of source table rows. Each row item in the returned
        list contains a list of cell data elements."""
        import StringIO
        import csv
        result = []
        rdr = csv.reader(StringIO.StringIO('\r\n'.join(rows)),
            skipinitialspace=True)
        try:
            for row in rdr:
                result.append(row)
        except Exception:
            raise EAsciiDoc,'csv parse error: %s' % row
        return result
    def parse_dsv(self,rows):
        """Parse the list of source table rows. Each row item in the returned
        list contains a list of cell data elements."""
        separator = self.attributes.get('separator',':')
        separator = eval('"'+separator+'"')
        if len(separator) != 1:
            raise EAsciiDoc,'malformed dsv separator: %s' % separator
        # TODO If separator is preceeded by an odd number of backslashes then
        # it is escaped and should not delimit.
        result = []
        for row in rows:
            # Skip blank lines
            if row == '': continue
            # Unescape escaped characters.
            row = eval('"'+row.replace('"','\\"')+'"')
            data = row.split(separator)
            data = [s.strip() for s in data]
            result.append(data)
        return result
    def translate(self):
        message.deprecated('old tables syntax')
        AbstractBlock.translate(self)
        # Reset instance specific properties.
        self.underline = None
        self.columns = []
        attrs = {}
        BlockTitle.consume(attrs)
        # Add relevant globals to table substitutions.
        attrs['pagewidth'] = str(config.pagewidth)
        attrs['pageunits'] = config.pageunits
        # Mix in document attribute list.
        AttributeList.consume(attrs)
        # Validate overridable attributes.
        for k,v in attrs.items():
            if k == 'format':
                if v not in self.FORMATS:
                    raise EAsciiDoc, 'illegal [%s] %s: %s' % (self.name,k,v)
                self.format = v
            elif k == 'tablewidth':
                try:
                    self.tablewidth = float(attrs['tablewidth'])
                except Exception:
                    raise EAsciiDoc, 'illegal [%s] %s: %s' % (self.name,k,v)
        self.merge_attributes(attrs)
        # Parse table ruler.
        ruler = reader.read()
        assert re.match(self.delimiter,ruler)
        self.parse_ruler(ruler)
        # Read the entire table.
        table = []
        while True:
            line = reader.read_next()
            # Table terminated by underline followed by a blank line or EOF.
            if len(table) > 0 and re.match(self.underline,table[-1]):
                if line in ('',None):
                    break;
            if line is None:
                raise EAsciiDoc,'closing [%s] underline expected' % self.name
            table.append(reader.read())
        # EXPERIMENTAL: The number of lines in the table, requested by Benjamin Klum.
        self.attributes['rows'] = str(len(table))
        #TODO: Inherited validate() doesn't set check_msg, needs checking.
        if self.check_msg:  # Skip if table definition was marked invalid.
            message.warning('skipping %s table: %s' % (self.name,self.check_msg))
            return
        # Generate colwidths and colspecs.
        self.build_colspecs()
        # Generate headrows, footrows, bodyrows.
        # Headrow, footrow and bodyrow data replaces same named attributes in
        # the table markup template. In order to ensure this data does not get
        # a second attribute substitution (which would interfere with any
        # already substituted inline passthroughs) unique placeholders are used
        # (the tab character does not appear elsewhere since it is expanded on
        # input) which are replaced after template attribute substitution.
        headrows = footrows = []
        bodyrows,table = self.split_rows(table)
        if table:
            headrows = bodyrows
            bodyrows,table = self.split_rows(table)
            if table:
                footrows,table = self.split_rows(table)
        if headrows:
            headrows = self.parse_rows(headrows, self.headrow, self.headdata)
            headrows = writer.newline.join(headrows)
            self.attributes['headrows'] = '\x07headrows\x07'
        if footrows:
            footrows = self.parse_rows(footrows, self.footrow, self.footdata)
            footrows = writer.newline.join(footrows)
            self.attributes['footrows'] = '\x07footrows\x07'
        bodyrows = self.parse_rows(bodyrows, self.bodyrow, self.bodydata)
        bodyrows = writer.newline.join(bodyrows)
        self.attributes['bodyrows'] = '\x07bodyrows\x07'
        table = subs_attrs(config.sections[self.template],self.attributes)
        table = writer.newline.join(table)
        # Before we finish replace the table head, foot and body place holders
        # with the real data.
        if headrows:
            table = table.replace('\x07headrows\x07', headrows, 1)
        if footrows:
            table = table.replace('\x07footrows\x07', footrows, 1)
        table = table.replace('\x07bodyrows\x07', bodyrows, 1)
        writer.write(table,trace='table')

class Tables_OLD(AbstractBlocks):
    """List of tables."""
    BLOCK_TYPE = Table_OLD
    PREFIX = 'old_tabledef-'
    def __init__(self):
        AbstractBlocks.__init__(self)
    def load(self,sections):
        AbstractBlocks.load(self,sections)
    def validate(self):
        # Does not call AbstractBlocks.validate().
        # Check we have a default table definition,
        for i in range(len(self.blocks)):
            if self.blocks[i].name == 'old_tabledef-default':
                default = self.blocks[i]
                break
        else:
            raise EAsciiDoc,'missing [OLD_tabledef-default] section'
        # Set default table defaults.
        if default.format is None: default.subs = 'fixed'
        # Propagate defaults to unspecified table parameters.
        for b in self.blocks:
            if b is not default:
                if b.fillchar is None: b.fillchar = default.fillchar
                if b.format is None: b.format = default.format
                if b.template is None: b.template = default.template
                if b.colspec is None: b.colspec = default.colspec
                if b.headrow is None: b.headrow = default.headrow
                if b.footrow is None: b.footrow = default.footrow
                if b.bodyrow is None: b.bodyrow = default.bodyrow
                if b.headdata is None: b.headdata = default.headdata
                if b.footdata is None: b.footdata = default.footdata
                if b.bodydata is None: b.bodydata = default.bodydata
        # Check all tables have valid fill character.
        for b in self.blocks:
            if not b.fillchar or len(b.fillchar) != 1:
                raise EAsciiDoc,'[%s] missing or illegal fillchar' % b.name
        # Build combined tables delimiter patterns and assign defaults.
        delimiters = []
        for b in self.blocks:
            # Ruler is:
            #   (ColStop,(ColWidth,FillChar+)?)+, FillChar+, TableWidth?
            b.delimiter = r'^(' + Table_OLD.COL_STOP \
                + r'(\d*|' + re.escape(b.fillchar) + r'*)' \
                + r')+' \
                + re.escape(b.fillchar) + r'+' \
                + '([\d\.]*)$'
            delimiters.append(b.delimiter)
            if not b.headrow:
                b.headrow = b.bodyrow
            if not b.footrow:
                b.footrow = b.bodyrow
            if not b.headdata:
                b.headdata = b.bodydata
            if not b.footdata:
                b.footdata = b.bodydata
        self.delimiters = re_join(delimiters)
        # Check table definitions are valid.
        for b in self.blocks:
            b.validate()
            if config.verbose:
                if b.check_msg:
                    message.warning('[%s] table definition: %s' % (b.name,b.check_msg))

# End of deprecated old table classes.
#---------------------------------------------------------------------------

#---------------------------------------------------------------------------
# Application code.
#---------------------------------------------------------------------------
# Constants
# ---------
APP_FILE = None             # This file's full path.
APP_DIR = None              # This file's directory.
USER_DIR = None             # ~/.asciidoc
# Global configuration files directory (set by Makefile build target).
CONF_DIR = '/etc/asciidoc'
HELP_FILE = 'help.conf'     # Default (English) help file.

# Globals
# -------
document = Document()       # The document being processed.
config = Config()           # Configuration file reader.
reader = Reader()           # Input stream line reader.
writer = Writer()           # Output stream line writer.
message = Message()         # Message functions.
paragraphs = Paragraphs()   # Paragraph definitions.
lists = Lists()             # List definitions.
blocks = DelimitedBlocks()  # DelimitedBlock definitions.
tables_OLD = Tables_OLD()   # Table_OLD definitions.
tables = Tables()           # Table definitions.
macros = Macros()           # Macro definitions.
calloutmap = CalloutMap()   # Coordinates callouts and callout list.
trace = Trace()             # Implements trace attribute processing.

### Used by asciidocapi.py ###
# List of message strings written to stderr.
messages = message.messages


def asciidoc(backend, doctype, confiles, infile, outfile, options):
    """Convert AsciiDoc document to DocBook document of type doctype
    The AsciiDoc document is read from file object src the translated
    DocBook file written to file object dst."""
    try:
        if doctype not in ('article','manpage','book'):
            raise EAsciiDoc,'illegal document type'
        document.backend = backend
        if not os.path.exists(os.path.join(APP_DIR, backend+'.conf')) and not \
               os.path.exists(os.path.join(CONF_DIR, backend+'.conf')):
            message.warning('non-standard %s backend' % backend, linenos=False)
        document.doctype = doctype
        document.infile = infile
        document.update_attributes()
        # Set processing options.
        for o in options:
            if o == '-c': config.dumping = True
            if o == '-s': config.header_footer = False
            if o == '-v': config.verbose = True
        # Check the infile exists.
        if infile != '<stdin>' and not os.path.isfile(infile):
            raise EAsciiDoc,'input file %s missing' % infile
        if '-e' not in options:
            config.load_all()
        if infile != '<stdin>':
            # Load implicit document specific configuration files if they exist.
            config.load_file(os.path.splitext(infile)[0] + '.conf')
            config.load_file(os.path.splitext(infile)[0] + '-' + backend + '.conf')
        # If user specified configuration file(s) overlay the defaults.
        if confiles:
            for conf in confiles:
                if os.path.isfile(conf):
                    config.load_file(conf)
                else:
                    raise EAsciiDoc,'configuration file %s missing' % conf
        document.update_attributes()
        # Check configuration for consistency.
        config.validate()
        # Build outfile name now all conf files have been read.
        if outfile is None:
            outfile = os.path.splitext(infile)[0] + '.' + backend
            if config.outfilesuffix:
                # Change file extension.
                outfile = os.path.splitext(outfile)[0] + config.outfilesuffix
        document.outfile = outfile
        if config.dumping:
            config.dump()
        else:
            reader.tabsize = config.tabsize
            reader.open(infile)
            try:
                writer.newline = config.newline
                writer.open(outfile)
                try:
                    AttributeList.initialize()
                    paragraphs.initialize()
                    lists.initialize()
                    document.update_attributes()   # Add file name related.
                    document.translate()
                finally:
                    writer.close()
            finally:
                reader.closefile()  # Keep reader state for postmortem.
    except KeyboardInterrupt:
        raise
    except Exception,e:
        # Cleanup.
        if outfile and outfile != '<stdout>' and os.path.isfile(outfile):
            os.unlink(outfile)
        # Build and print error description.
        msg = 'FAILED: '
        if reader.cursor:
            msg = msg + message.format('')
        if isinstance(e,EAsciiDoc):
            message.stderr(msg+str(e))
        else:
            if __name__ == '__main__':
                message.stderr(msg+'unexpected error:')
                message.stderr('-'*60)
                traceback.print_exc(file=sys.stderr)
                message.stderr('-'*60)
            else:
                message.stderr('%sunexpected error: %s' % (msg,str(e)))
        sys.exit(1)

def usage(msg=''):
    if msg:
        message.stderr(msg)
    show_help('default', sys.stderr)

def show_help(topic, f=None):
    """Print help topic to file object f."""
    if f is None:
        f = sys.stdout
    # Select help file.
    lang = config.cmd_attrs.get('lang')
    if lang and lang != 'en':
        help_file = 'help-' + lang + '.conf'
    else:
        help_file = HELP_FILE
    # Print [topic] section from help file.
    topics = OrderedDict()
    load_conf_file(topics, help_file, CONF_DIR)
    load_conf_file(topics, help_file, APP_DIR)
    if USER_DIR is not None:
        load_conf_file(topics, help_file, USER_DIR)
    if len(topics) == 0:
        # Default to English if specified language help files not found.
        help_file = HELP_FILE
        load_conf_file(topics, help_file, CONF_DIR)
        load_conf_file(topics, help_file, APP_DIR)
    if len(topics) == 0:
        message.stderr('no help topics found')
        sys.exit(1)
    n = 0
    for k in topics.keys():
        if re.match(re.escape(topic), k):
            n += 1
            lines = topics[k]
    if n == 0:
        message.stderr('help topic not found: [%s] in %s' % (topic, help_file))
        message.stderr('available help topics: %s' % ', '.join(topics.keys()))
        sys.exit(1)
    elif n > 1:
        message.stderr('ambiguous help topic: %s' % topic)
    else:
        for line in lines:
            print >>f, line

### Used by asciidocapi.py ###
def execute(cmd,opts,args):
    """
    Execute asciidoc with command-line options and arguments.
    cmd is asciidoc command or asciidoc.py path.
    opts and args conform to values returned by getopt.getopt().
    Raises SystemExit if an error occurs.

    Doctests:

    1. Check execution:

       >>> import StringIO
       >>> infile = StringIO.StringIO('Hello *{author}*')
       >>> outfile = StringIO.StringIO()
       >>> opts = []
       >>> opts.append(('--backend','html4'))
       >>> opts.append(('--no-header-footer',None))
       >>> opts.append(('--attribute','author=Joe Bloggs'))
       >>> opts.append(('--out-file',outfile))
       >>> execute(__file__, opts, [infile])
       >>> print outfile.getvalue()
       <p>Hello <strong>Joe Bloggs</strong></p>

       >>>

    """
    if float(sys.version[:3]) < MIN_PYTHON_VERSION:
        message.stderr('FAILED: Python 2.3 or better required')
        sys.exit(1)
    if not os.path.exists(cmd):
        message.stderr('FAILED: Missing asciidoc command: %s' % cmd)
        sys.exit(1)
    # Locate the executable and configuration files directory.
    global APP_FILE
    APP_FILE = os.path.realpath(cmd)
    global APP_DIR
    APP_DIR = os.path.dirname(APP_FILE)
    global USER_DIR
    USER_DIR = os.environ.get('HOME')
    if USER_DIR is not None:
        USER_DIR = os.path.join(USER_DIR,'.asciidoc')
        if not os.path.isdir(USER_DIR):
            USER_DIR = None
    if len(args) > 1:
        usage('To many arguments')
        sys.exit(1)
    backend = DEFAULT_BACKEND
    doctype = DEFAULT_DOCTYPE
    confiles = []
    outfile = None
    options = []
    help_option = False
    for o,v in opts:
        if o in ('--help','-h'):
            help_option = True
        if o == '--unsafe':
            document.safe = False
        if o == '--version':
            print('asciidoc %s' % VERSION)
            sys.exit(0)
        if o in ('-b','--backend'):
            backend = v
        if o in ('-c','--dump-conf'):
            options.append('-c')
        if o in ('-d','--doctype'):
            doctype = v
        if o in ('-e','--no-conf'):
            options.append('-e')
        if o in ('-f','--conf-file'):
            confiles.append(v)
        if o in ('-n','--section-numbers'):
            o = '-a'
            v = 'numbered'
        if o in ('-a','--attribute'):
            e = parse_entry(v, allow_name_only=True)
            if not e:
                usage('Illegal -a option: %s' % v)
                sys.exit(1)
            k,v = e
            # A @ suffix denotes don't override existing document attributes.
            if v and v[-1] == '@':
                document.attributes[k] = v[:-1]
            else:
                config.cmd_attrs[k] = v
        if o in ('-o','--out-file'):
            outfile = v
        if o in ('-s','--no-header-footer'):
            options.append('-s')
        if o in ('-v','--verbose'):
            options.append('-v')
    if help_option:
        if len(args) == 0:
            show_help('default')
        else:
            show_help(args[-1])
        sys.exit(0)
    if len(args) == 0 and len(opts) == 0:
        usage()
        sys.exit(0)
    if len(args) == 0:
        usage('No source file specified')
        sys.exit(1)
    if not backend:
        usage('No --backend option specified')
        sys.exit(1)
    stdin,stdout = sys.stdin,sys.stdout
    try:
        infile = args[0]
        if infile == '-':
            infile = '<stdin>'
        elif isinstance(infile, str):
            infile = os.path.abspath(infile)
        else:   # Input file is file object from API call.
            sys.stdin = infile
            infile = '<stdin>'
        if outfile == '-':
            outfile = '<stdout>'
        elif isinstance(outfile, str):
            outfile = os.path.abspath(outfile)
        elif outfile is None:
            if infile == '<stdin>':
                outfile = '<stdout>'
        else:   # Output file is file object from API call.
            sys.stdout = outfile
            outfile = '<stdout>'
        # Do the work.
        asciidoc(backend, doctype, confiles, infile, outfile, options)
        if document.has_errors:
            sys.exit(1)
    finally:
        sys.stdin,sys.stdout = stdin,stdout

if __name__ == '__main__':
    # Process command line options.
    import getopt
    try:
        #DEPRECATED: --safe option.
        opts,args = getopt.getopt(sys.argv[1:],
            'a:b:cd:ef:hno:svw:',
            ['attribute=','backend=','conf-file=','doctype=','dump-conf',
            'help','no-conf','no-header-footer','out-file=',
            'section-numbers','verbose','version','safe','unsafe',
            'doctest'])
    except getopt.GetoptError:
        usage('illegal command options')
        sys.exit(1)
    if '--doctest' in [opt[0] for opt in opts]:
        # Run module doctests.
        import doctest
        options = doctest.NORMALIZE_WHITESPACE + doctest.ELLIPSIS
        failures,tries = doctest.testmod(optionflags=options)
        if failures == 0:
            message.stderr('All doctests passed')
            exit(0)
        else:
            exit(1)
    try:
        execute(sys.argv[0],opts,args)
    except KeyboardInterrupt:
        message.stderr()
