/* Copyright (C) 1993, 2000 Aladdin Enterprises.  All rights reserved.
  
  This program is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License version 2
  as published by the Free Software Foundation.


  This software is provided AS-IS with no warranty, either express or
  implied. That is, this program is distributed in the hope that it will 
  be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details

  You should have received a copy of the GNU General Public License along
  with this program; if not, write to the Free Software Foundation, Inc.,
  59 Temple Place, Suite 330, Boston, MA, 02111-1307.
  
  For more information about licensing, please refer to
  http://www.ghostscript.com/licensing/. For information on
  commercial licensing, go to http://www.artifex.com/licensing/ or
  contact Artifex Software, Inc., 101 Lucas Valley Road #110,
  San Rafael, CA  94903, U.S.A., +1(415)492-9861.
*/

/* $Id: iparam.c,v 1.8 2002/06/16 03:48:22 lpd Exp $ */
/* Interpreter implementations of parameter dictionaries */
#include "memory_.h"
#include "string_.h"
#include "ghost.h"
#include "errors.h"
#include "oper.h"		/* for check_type */
#include "opcheck.h"
#include "ialloc.h"
#include "idict.h"
#include "imemory.h"		/* for iutil.h */
#include "iname.h"
#include "istack.h"
#include "iparam.h"
#include "iutil.h"		/* for num_params */
#include "ivmspace.h"
#include "store.h"

/* ================ Utilities ================ */

/* Convert a key to a ref. */
private int
ref_param_key(const iparam_list * plist, gs_param_name pkey, ref * pkref)
{
    if (plist->int_keys) {
	long key;

	if (sscanf(pkey, "%ld", &key) != 1)
	    return_error(e_rangecheck);
	make_int(pkref, key);
	return 0;
    } else
	return name_ref((const byte *)pkey, strlen(pkey), pkref, 0);
}

/* Fill in a gs_param_key_t from a name or int ref. */
private int
ref_to_key(const ref * pref, gs_param_key_t * key, iparam_list *plist)
{
    if (r_has_type(pref, t_name)) {
	ref nref;

	name_string_ref(pref, &nref);
	key->data = nref.value.const_bytes;
	key->size = r_size(&nref);
	key->persistent = false; /* names may be freed */
    } else if (r_has_type(pref, t_integer)) {
	char istr[sizeof(long) * 8 / 3 + 2];
	int len;
	byte *buf;

	sprintf(istr, "%ld", pref->value.intval);
	len = strlen(istr);
	/* GC will take care of freeing this: */
	buf = gs_alloc_string(plist->memory, len, "ref_to_key");
	if (!buf)
	    return_error(e_VMerror);
	key->data = buf;
	key->size = len;
	key->persistent = true;
    } else
	return_error(e_typecheck);
    return 0;
}

/* ================ Writing parameters to refs ================ */

/* Forward references */
private int array_new_indexed_plist_write(dict_param_list *plist,
					  ref *parray, const ref *pwanted,
					  gs_ref_memory_t *imem);

/* ---------------- Generic writing procedures ---------------- */

private param_proc_begin_xmit_collection(ref_param_begin_write_collection);
private param_proc_end_xmit_collection(ref_param_end_write_collection);
private param_proc_xmit_typed(ref_param_write_typed);
private param_proc_next_key(ref_param_get_next_key);
private param_proc_requested(ref_param_requested);
private const gs_param_list_procs ref_write_procs =
{
    ref_param_write_typed,
    ref_param_begin_write_collection,
    ref_param_end_write_collection,
    ref_param_get_next_key,
    NULL,			/* request */
    ref_param_requested
};
private int ref_array_param_requested(const iparam_list *, gs_param_name,
				      ref *, uint, client_name_t);
private int ref_param_write(iparam_list *, gs_param_name, const ref *);
private int ref_param_write_string_value(ref *, const gs_param_string *,
					 gs_ref_memory_t *);
private int ref_param_write_name_value(ref *, const gs_param_string *);
private int
ref_param_make_int(ref *pe, const void *pvalue, uint i, gs_ref_memory_t *imem)
{
    make_tav(pe, t_integer, imemory_new_mask(imem), intval,
	     ((const gs_param_int_array *)pvalue)->data[i]);
    return 0;
}
private int
ref_param_make_float(ref *pe, const void *pvalue, uint i, gs_ref_memory_t *imem)
{
    make_tav(pe, t_real, imemory_new_mask(imem), realval,
	     ((const gs_param_float_array *)pvalue)->data[i]);
    return 0;
}
private int
ref_param_make_string(ref *pe, const void *pvalue, uint i, gs_ref_memory_t *imem)
{
    return ref_param_write_string_value(pe,
			 &((const gs_param_string_array *)pvalue)->data[i],
					imem);
}
private int
ref_param_make_name(ref * pe, const void *pvalue, uint i, gs_ref_memory_t *imem)
{
    return ref_param_write_name_value(pe,
			 &((const gs_param_string_array *)pvalue)->data[i]);
}
private int
ref_param_write_typed_array(gs_param_list * plist, gs_param_name pkey,
			    void *pvalue, uint count,
			    int (*make)(ref *, const void *, uint,
					gs_ref_memory_t *))
{
    iparam_list *const iplist = (iparam_list *) plist;
    ref value;
    uint i;
    ref *pe;
    int code;

    if ((code = ref_array_param_requested(iplist, pkey, &value, count,
				       "ref_param_write_typed_array")) <= 0)
	return code;
    for (i = 0, pe = value.value.refs; i < count; ++i, ++pe)
	if ((code = (*make) (pe, pvalue, i, iplist->ref_memory)) < 0)
	    return code;
    return ref_param_write(iplist, pkey, &value);
}
private int
ref_param_begin_write_collection(gs_param_list * plist, gs_param_name pkey,
				 gs_param_dict * pvalue,
				 gs_param_collection_type_t coll_type)
{
    iparam_list *const iplist = (iparam_list *) plist;
    gs_ref_memory_t *imem = iplist->ref_memory;
    dict_param_list *dlist = (dict_param_list *)
	gs_alloc_bytes(plist->memory, size_of(dict_param_list),
		       "ref_param_begin_write_collection");
    int code;

    if (dlist == 0)
	return_error(e_VMerror);
    if (coll_type != gs_param_collection_array) {
	ref dref;

	code = dict_alloc(imem, pvalue->size, &dref);
	if (code >= 0) {
	    code = dict_param_list_write(dlist, &dref, NULL, imem);
	    dlist->int_keys = coll_type == gs_param_collection_dict_int_keys;
	}
    } else {
	ref aref;

	code = gs_alloc_ref_array(imem, &aref, a_all, pvalue->size,
				  "ref_param_begin_write_collection");
	if (code >= 0)
	    code = array_new_indexed_plist_write(dlist, &aref, NULL, imem);
    }
    if (code < 0)
	gs_free_object(plist->memory, dlist, "ref_param_begin_write_collection");
    else
	pvalue->list = (gs_param_list *) dlist;
    return code;
}
private int
ref_param_end_write_collection(gs_param_list * plist, gs_param_name pkey,
			       gs_param_dict * pvalue)
{
    iparam_list *const iplist = (iparam_list *) plist;
    int code = ref_param_write(iplist, pkey,
			       &((dict_param_list *) pvalue->list)->dict);

    gs_free_object(plist->memory, pvalue->list, "ref_param_end_write_collection");
    return code;
}
private int
ref_param_write_typed(gs_param_list * plist, gs_param_name pkey,
		      gs_param_typed_value * pvalue)
{
    iparam_list *const iplist = (iparam_list *) plist;
    ref value;
    int code = 0;

    switch (pvalue->type) {
	case gs_param_type_null:
	    make_null(&value);
	    break;
	case gs_param_type_bool:
	    make_bool(&value, pvalue->value.b);
	    break;
	case gs_param_type_int:
	    make_int(&value, pvalue->value.i);
	    break;
	case gs_param_type_long:
	    make_int(&value, pvalue->value.l);
	    break;
	case gs_param_type_float:
	    make_real(&value, pvalue->value.f);
	    break;
	case gs_param_type_string:
	    if (!ref_param_requested(plist, pkey))
		return 0;
	    code = ref_param_write_string_value(&value, &pvalue->value.s,
						iplist->ref_memory);
	    break;
	case gs_param_type_name:
	    if (!ref_param_requested(plist, pkey))
		return 0;
	    code = ref_param_write_name_value(&value, &pvalue->value.n);
	    break;
	case gs_param_type_int_array:
	    return ref_param_write_typed_array(plist, pkey, &pvalue->value.ia,
					       pvalue->value.ia.size,
					       ref_param_make_int);
	case gs_param_type_float_array:
	    return ref_param_write_typed_array(plist, pkey, &pvalue->value.fa,
					       pvalue->value.fa.size,
					       ref_param_make_float);
	case gs_param_type_string_array:
	    return ref_param_write_typed_array(plist, pkey, &pvalue->value.sa,
					       pvalue->value.sa.size,
					       ref_param_make_string);
	case gs_param_type_name_array:
	    return ref_param_write_typed_array(plist, pkey, &pvalue->value.na,
					       pvalue->value.na.size,
					       ref_param_make_name);
	case gs_param_type_dict:
	case gs_param_type_dict_int_keys:
	case gs_param_type_array:
	    return ref_param_begin_write_collection(plist, pkey,
						    &pvalue->value.d,
	      (gs_param_collection_type_t)(pvalue->type - gs_param_type_dict));
	default:
	    return_error(e_typecheck);
    }
    if (code < 0)
	return code;
    return ref_param_write(iplist, pkey, &value);
}

/* Check whether a given parameter was requested. */
private int
ref_param_requested(const gs_param_list * plist, gs_param_name pkey)
{
    const iparam_list *const ciplist = (const iparam_list *)plist;
    ref kref;
    ref *ignore_value;

    if (!r_has_type(&ciplist->u.w.wanted, t_dictionary))
	return -1;
    if (ref_param_key(ciplist, pkey, &kref) < 0)
	return -1;		/* catch it later */
    return (dict_find(&ciplist->u.w.wanted, &kref, &ignore_value) > 0);
}

/* Check whether an array parameter is wanted, and allocate it if so. */
/* Return <0 on error, 0 if not wanted, 1 if wanted. */
private int
ref_array_param_requested(const iparam_list *iplist, gs_param_name pkey,
			  ref *pvalue, uint size, client_name_t cname)
{
    int code;

    if (!ref_param_requested((const gs_param_list *)iplist, pkey))
	return 0;
    code = gs_alloc_ref_array(iplist->ref_memory, pvalue, a_all, size, cname);
    return (code < 0 ? code : 1);
}

/* ---------------- Internal routines ---------------- */

/* Prepare to write a string value. */
private int
ref_param_write_string_value(ref * pref, const gs_param_string * pvalue,
			     gs_ref_memory_t *imem)
{
    const byte *pdata = pvalue->data;
    uint n = pvalue->size;

    if (pvalue->persistent)
	make_const_string(pref, a_readonly | avm_foreign, n, pdata);
    else {
	byte *pstr = gs_alloc_string((gs_memory_t *)imem, n,
				     "ref_param_write_string");

	if (pstr == 0)
	    return_error(e_VMerror);
	memcpy(pstr, pdata, n);
	make_string(pref, a_readonly | imemory_space(imem), n, pstr);
    }
    return 0;
}

/* Prepare to write a name value. */
private int
ref_param_write_name_value(ref * pref, const gs_param_string * pvalue)
{
    return name_ref(pvalue->data, pvalue->size, pref,
		    (pvalue->persistent ? 0 : 1));
}

/* Generic routine for writing a ref parameter. */
private int
ref_param_write(iparam_list * plist, gs_param_name pkey, const ref * pvalue)
{
    ref kref;
    int code;

    if (!ref_param_requested((gs_param_list *) plist, pkey))
	return 0;
    code = ref_param_key(plist, pkey, &kref);
    if (code < 0)
	return code;
    return (*plist->u.w.write) (plist, &kref, pvalue);
}

/* ---------------- Implementations ---------------- */

/* Initialize for writing parameters. */
private void
ref_param_write_init(iparam_list * plist, const ref * pwanted,
		     gs_ref_memory_t *imem)
{
    gs_param_list_init((gs_param_list *)plist, &ref_write_procs,
		       (gs_memory_t *)imem);
    plist->ref_memory = imem;
    if (pwanted == 0)
	make_null(&plist->u.w.wanted);
    else
	plist->u.w.wanted = *pwanted;
    plist->results = 0;
    plist->int_keys = false;
}

/* Implementation for getting parameters to a stack. */
private int
stack_param_write(iparam_list * plist, const ref * pkey, const ref * pvalue)
{
    stack_param_list *const splist = (stack_param_list *) plist;
    ref_stack_t *pstack = splist->pstack;
    s_ptr p = pstack->p;

    if (pstack->top - p < 2) {
	int code = ref_stack_push(pstack, 2);

	if (code < 0)
	    return code;
	*ref_stack_index(pstack, 1) = *pkey;
	p = pstack->p;
    } else {
	pstack->p = p += 2;
	p[-1] = *pkey;
    }
    *p = *pvalue;
    splist->count++;
    return 0;
}

/* Implementation for enumerating parameters on a stack */
private int			/* ret 0 ok, 1 if EOF, or -ve err */
stack_param_enumerate(iparam_list * plist, gs_param_enumerator_t * penum,
		      gs_param_key_t * key, ref_type * type)
{
    int code;
    stack_param_list *const splist = (stack_param_list *) plist;
    long index = penum->intval;
    ref *stack_element;

    do {
	stack_element =
	    ref_stack_index(splist->pstack, index + 1 + splist->skip);
	if (!stack_element)
	    return 1;
    } while (index += 2, !r_has_type(stack_element, t_name));
    *type = r_type(stack_element);
    code = ref_to_key(stack_element, key, plist);
    penum->intval = index;
    return code;
}

int
stack_param_list_write(stack_param_list * plist, ref_stack_t * pstack,
		       const ref * pwanted, gs_ref_memory_t *imem)
{
    plist->u.w.write = stack_param_write;
    ref_param_write_init((iparam_list *) plist, pwanted, imem);
    plist->enumerate = stack_param_enumerate;
    plist->pstack = pstack;
    plist->skip = 0;
    plist->count = 0;
    return 0;
}

/* Implementation for getting parameters to a dictionary. */
private int
dict_param_write(iparam_list * plist, const ref * pkey, const ref * pvalue)
{
    int code =
	dict_put(&((dict_param_list *) plist)->dict, pkey, pvalue, NULL);

    return min(code, 0);
}

/* Implementation for enumerating parameters in a dictionary */
private int			/* ret 0 ok, 1 if EOF, or -ve err */
dict_param_enumerate(iparam_list * plist, gs_param_enumerator_t * penum,
		     gs_param_key_t * key, ref_type * type)
{
    ref elt[2];
    int code;
    dict_param_list *const pdlist = (dict_param_list *) plist;
    int index =
    (penum->intval != 0 ? penum->intval : dict_first(&pdlist->dict));

    index = dict_next(&pdlist->dict, index, elt);
    if (index < 0)
	return 1;
    *type = r_type(&elt[1]);
    code = ref_to_key(&elt[0], key, plist);
    penum->intval = index;
    return code;
}

int
dict_param_list_write(dict_param_list *plist, ref *pdict, const ref *pwanted,
		      gs_ref_memory_t *imem)
{
    check_dict_write(*pdict);
    plist->u.w.write = dict_param_write;
    plist->enumerate = dict_param_enumerate;
    ref_param_write_init((iparam_list *) plist, pwanted, imem);
    plist->dict = *pdict;
    return 0;
}

/* Implementation for getting parameters to an indexed array. */
/* Note that this is now internal, since it only handles "new" arrays. */
private int
array_new_indexed_param_write(iparam_list * iplist, const ref * pkey,
			  const ref * pvalue)
{
    const ref *const arr = &((dict_param_list *)iplist)->dict;
    ref *eltp;

    if (!r_has_type(pkey, t_integer))
	return_error(e_typecheck);
    check_int_ltu(*pkey, r_size(arr));
    store_check_dest(arr, pvalue);
    eltp = arr->value.refs + pkey->value.intval;
    /* ref_assign_new(eltp, pvalue); */
    ref_assign(eltp, pvalue);
    r_set_attrs(eltp, imemory_new_mask(iplist->ref_memory));
    return 0;
}
private int
array_new_indexed_plist_write(dict_param_list * plist, ref * parray,
			      const ref * pwanted, gs_ref_memory_t *imem)
{
    check_array(*parray);
    check_write(*parray);
    plist->u.w.write = array_new_indexed_param_write;
    ref_param_write_init((iparam_list *) plist, pwanted, imem);
    plist->dict = *parray;
    plist->int_keys = true;
    return 0;
}

/* ================ Reading refs to parameters ================ */

/* ---------------- Generic reading procedures ---------------- */

private param_proc_begin_xmit_collection(ref_param_begin_read_collection);
private param_proc_end_xmit_collection(ref_param_end_read_collection);
private param_proc_xmit_typed(ref_param_read_typed);

/*private param_proc_next_key(ref_param_get_next_key); already dec'ld above */
private param_proc_get_policy(ref_param_read_get_policy);
private param_proc_signal_error(ref_param_read_signal_error);
private param_proc_commit(ref_param_read_commit);
private const gs_param_list_procs ref_read_procs =
{
    ref_param_read_typed,
    ref_param_begin_read_collection,
    ref_param_end_read_collection,
    ref_param_get_next_key,
    NULL,			/* request */
    NULL,			/* requested */
    ref_param_read_get_policy,
    ref_param_read_signal_error,
    ref_param_read_commit
};
private int ref_param_read(iparam_list *, gs_param_name,
			   iparam_loc *, int);
private int ref_param_read_string_value(const iparam_loc *,
					gs_param_string *);
private int ref_param_read_array(iparam_list *, gs_param_name,
				 iparam_loc *);

#define iparam_note_error(loc, code)\
  gs_note_error(*(loc).presult = code)
#define iparam_check_type(loc, typ)\
  if ( !r_has_type((loc).pvalue, typ) )\
    return iparam_note_error(loc, e_typecheck)
#define iparam_check_read(loc)\
  if ( !r_has_attr((loc).pvalue, a_read) )\
    return iparam_note_error(loc, e_invalidaccess)

private int
ref_param_read_int_array(gs_param_list * plist, gs_param_name pkey,
			 gs_param_int_array * pvalue)
{
    iparam_list *const iplist = (iparam_list *) plist;
    iparam_loc loc;
    int code = ref_param_read_array(iplist, pkey, &loc);
    int *piv;
    uint size;
    long i;

    if (code != 0)
	return code;
    size = r_size(loc.pvalue);
    piv = (int *)gs_alloc_byte_array(plist->memory, size, sizeof(int),
				     "ref_param_read_int_array");

    if (piv == 0)
	return_error(e_VMerror);
    for (i = 0; i < size; i++) {
	ref elt;

	array_get(loc.pvalue, i, &elt);
	if (!r_has_type(&elt, t_integer)) {
	    code = gs_note_error(e_typecheck);
	    break;
	}
#if arch_sizeof_int < arch_sizeof_long
	if (elt.value.intval != (int)elt.value.intval) {
	    code = gs_note_error(e_rangecheck);
	    break;
	}
#endif
	piv[i] = (int)elt.value.intval;
    }
    if (code < 0) {
	gs_free_object(plist->memory, piv, "ref_param_read_int_array");
	return (*loc.presult = code);
    }
    pvalue->data = piv;
    pvalue->size = size;
    pvalue->persistent = true;
    return 0;
}
private int
ref_param_read_float_array(gs_param_list * plist, gs_param_name pkey,
			   gs_param_float_array * pvalue)
{
    iparam_list *const iplist = (iparam_list *) plist;
    iparam_loc loc;
    ref aref, elt;
    int code = ref_param_read_array(iplist, pkey, &loc);
    float *pfv;
    uint size;
    long i;

    if (code != 0)
	return code;
    size = r_size(loc.pvalue);
    pfv = (float *)gs_alloc_byte_array(plist->memory, size, sizeof(float),
				       "ref_param_read_float_array");

    if (pfv == 0)
	return_error(e_VMerror);
    aref = *loc.pvalue;
    loc.pvalue = &elt;
    for (i = 0; code >= 0 && i < size; i++) {
	array_get(&aref, i, &elt);
	code = float_param(&elt, pfv + i);
    }
    if (code < 0) {
	gs_free_object(plist->memory, pfv, "ref_read_float_array_param");
	return (*loc.presult = code);
    }
    pvalue->data = pfv;
    pvalue->size = size;
    pvalue->persistent = true;
    return 0;
}
private int
ref_param_read_string_array(gs_param_list * plist, gs_param_name pkey,
			    gs_param_string_array * pvalue)
{
    iparam_list *const iplist = (iparam_list *) plist;
    iparam_loc loc;
    ref aref;
    int code = ref_param_read_array(iplist, pkey, &loc);
    gs_param_string *psv;
    uint size;
    long i;

    if (code != 0)
	return code;
    size = r_size(loc.pvalue);
    psv = (gs_param_string *)
	gs_alloc_byte_array(plist->memory, size, sizeof(gs_param_string),
			    "ref_param_read_string_array");
    if (psv == 0)
	return_error(e_VMerror);
    aref = *loc.pvalue;
    if (r_has_type(&aref, t_array)) {
	for (i = 0; code >= 0 && i < size; i++) {
	    loc.pvalue = aref.value.refs + i;
	    code = ref_param_read_string_value(&loc, psv + i);
	}
    } else {
	ref elt;

	loc.pvalue = &elt;
	for (i = 0; code >= 0 && i < size; i++) {
	    array_get(&aref, i, &elt);
	    code = ref_param_read_string_value(&loc, psv + i);
	}
    }
    if (code < 0) {
	gs_free_object(plist->memory, psv, "ref_param_read_string_array");
	return (*loc.presult = code);
    }
    pvalue->data = psv;
    pvalue->size = size;
    pvalue->persistent = true;
    return 0;
}
private int
ref_param_begin_read_collection(gs_param_list * plist, gs_param_name pkey,
				gs_param_dict * pvalue,
				gs_param_collection_type_t coll_type)
{
    iparam_list *const iplist = (iparam_list *) plist;
    iparam_loc loc;
    bool int_keys = coll_type != 0;
    int code = ref_param_read(iplist, pkey, &loc, -1);
    dict_param_list *dlist;

    if (code != 0)
	return code;
    dlist = (dict_param_list *)
	gs_alloc_bytes(plist->memory, size_of(dict_param_list),
		       "ref_param_begin_read_collection");
    if (dlist == 0)
	return_error(e_VMerror);
    if (r_has_type(loc.pvalue, t_dictionary)) {
	code = dict_param_list_read(dlist, loc.pvalue, NULL, false,
				    iplist->ref_memory);
	dlist->int_keys = int_keys;
	if (code >= 0)
	    pvalue->size = dict_length(loc.pvalue);
    } else if (int_keys && r_is_array(loc.pvalue)) {
	code = array_indexed_param_list_read(dlist, loc.pvalue, NULL, false,
					     iplist->ref_memory);
	if (code >= 0)
	    pvalue->size = r_size(loc.pvalue);
    } else
	code = gs_note_error(e_typecheck);
    if (code < 0) {
	gs_free_object(plist->memory, dlist, "ref_param_begin_write_collection");
	return iparam_note_error(loc, code);
    }
    pvalue->list = (gs_param_list *) dlist;
    return 0;
}
private int
ref_param_end_read_collection(gs_param_list * plist, gs_param_name pkey,
			      gs_param_dict * pvalue)
{
    iparam_list_release((dict_param_list *) pvalue->list);
    gs_free_object(plist->memory, pvalue->list,
		   "ref_param_end_read_collection");
    return 0;
}
private int
ref_param_read_typed(gs_param_list * plist, gs_param_name pkey,
		     gs_param_typed_value * pvalue)
{
    iparam_list *const iplist = (iparam_list *) plist;
    iparam_loc loc;
    ref elt;
    int code = ref_param_read(iplist, pkey, &loc, -1);

    if (code != 0)
	return code;
    switch (r_type(loc.pvalue)) {
	case t_array:
	case t_mixedarray:
	case t_shortarray:
	    iparam_check_read(loc);
	    if (r_size(loc.pvalue) <= 0) {
		/* 0-length array; can't get type info */
		pvalue->type = gs_param_type_array;
		pvalue->value.d.list = 0;
		pvalue->value.d.size = 0;
		return 0;
	    }
	    /*
	     * We have to guess at the array type.  First we guess based
	     * on the type of the first element of the array.  If that
	     * fails, we try again with more general types.
	     */
	    array_get(loc.pvalue, 0, &elt);
	    switch (r_type(&elt)) {
		case t_integer:
		    pvalue->type = gs_param_type_int_array;
		    code = ref_param_read_int_array(plist, pkey,
						    &pvalue->value.ia);
		    if (code != e_typecheck)
			return code;
		    /* This might be a float array.  Fall through. */
		    *loc.presult = 0;  /* reset error */
		case t_real:
		    pvalue->type = gs_param_type_float_array;
		    return ref_param_read_float_array(plist, pkey,
						      &pvalue->value.fa);
		case t_string:
		    pvalue->type = gs_param_type_string_array;
		    return ref_param_read_string_array(plist, pkey,
						       &pvalue->value.sa);
		case t_name:
		    pvalue->type = gs_param_type_name_array;
		    return ref_param_read_string_array(plist, pkey,
						       &pvalue->value.na);
		default:
		    break;
	    }
	    return gs_note_error(e_typecheck);
	case t_boolean:
	    pvalue->type = gs_param_type_bool;
	    pvalue->value.b = loc.pvalue->value.boolval;
	    return 0;
	case t_dictionary:
	    code = ref_param_begin_read_collection(plist, pkey,
			    &pvalue->value.d, gs_param_collection_dict_any);
	    if (code < 0)
		return code;
	    pvalue->type = gs_param_type_dict;

	    /* fixup new dict's type & int_keys field if contents have int keys */
	    {
		gs_param_enumerator_t enumr;
		gs_param_key_t key;
		ref_type keytype;

		param_init_enumerator(&enumr);
		if (!(*((iparam_list *) plist)->enumerate)
		    ((iparam_list *) pvalue->value.d.list, &enumr, &key, &keytype)
		    && keytype == t_integer) {
		    ((dict_param_list *) pvalue->value.d.list)->int_keys = 1;
		    pvalue->type = gs_param_type_dict_int_keys;
		}
	    }
	    return 0;
	case t_integer:
	    pvalue->type = gs_param_type_long;
	    pvalue->value.l = loc.pvalue->value.intval;
	    return 0;
	case t_name:
	    pvalue->type = gs_param_type_name;
	    return ref_param_read_string_value(&loc, &pvalue->value.n);
	case t_null:
	    pvalue->type = gs_param_type_null;
	    return 0;
	case t_real:
	    pvalue->value.f = loc.pvalue->value.realval;
	    pvalue->type = gs_param_type_float;
	    return 0;
	case t_string:
	    pvalue->type = gs_param_type_string;
	    return ref_param_read_string_value(&loc, &pvalue->value.s);
	default:
	    break;
    }
    return gs_note_error(e_typecheck);
}

private int
ref_param_read_get_policy(gs_param_list * plist, gs_param_name pkey)
{
    iparam_list *const iplist = (iparam_list *) plist;
    ref *pvalue;

    if (!(r_has_type(&iplist->u.r.policies, t_dictionary) &&
	  dict_find_string(&iplist->u.r.policies, pkey, &pvalue) > 0 &&
	  r_has_type(pvalue, t_integer))
	)
	return gs_param_policy_ignore;
    return (int)pvalue->value.intval;
}
private int
ref_param_read_signal_error(gs_param_list * plist, gs_param_name pkey, int code)
{
    iparam_list *const iplist = (iparam_list *) plist;
    iparam_loc loc;

    ref_param_read(iplist, pkey, &loc, -1);	/* can't fail */
    *loc.presult = code;
    switch (ref_param_read_get_policy(plist, pkey)) {
	case gs_param_policy_ignore:
	    return 0;
	case gs_param_policy_consult_user:
	    return_error(e_configurationerror);
	default:
	    return code;
    }
}
private int
ref_param_read_commit(gs_param_list * plist)
{
    iparam_list *const iplist = (iparam_list *) plist;
    int i;
    int ecode = 0;

    if (!iplist->u.r.require_all)
	return 0;
    /* Check to make sure that all parameters were actually read. */
    for (i = 0; i < iplist->count; ++i)
	if (iplist->results[i] == 0)
	    iplist->results[i] = ecode = gs_note_error(e_undefined);
    return ecode;
}
private int
ref_param_get_next_key(gs_param_list * plist, gs_param_enumerator_t * penum,
		       gs_param_key_t * key)
{
    ref_type keytype;		/* result not needed here */
    iparam_list *const pilist = (iparam_list *) plist;

    return (*pilist->enumerate) (pilist, penum, key, &keytype);
}

/* ---------------- Internal routines ---------------- */

/* Read a string value. */
private int
ref_param_read_string_value(const iparam_loc * ploc, gs_param_string * pvalue)
{
    const ref *pref = ploc->pvalue;

    switch (r_type(pref)) {
	case t_name: {
	    ref nref;

	    name_string_ref(pref, &nref);
	    pvalue->data = nref.value.const_bytes;
	    pvalue->size = r_size(&nref);
	    pvalue->persistent = true;
	}
	    break;
	case t_string:
	    iparam_check_read(*ploc);
	    pvalue->data = pref->value.const_bytes;
	    pvalue->size = r_size(pref);
	    pvalue->persistent = false;
	    break;
	default:
	    return iparam_note_error(*ploc, e_typecheck);
    }
    return 0;
}

/* Read an array (or packed array) parameter. */
private int
ref_param_read_array(iparam_list * plist, gs_param_name pkey, iparam_loc * ploc)
{
    int code = ref_param_read(plist, pkey, ploc, -1);

    if (code != 0)
	return code;
    if (!r_is_array(ploc->pvalue))
	return iparam_note_error(*ploc, e_typecheck);
    iparam_check_read(*ploc);
    return 0;
}

/* Generic routine for reading a ref parameter. */
private int
ref_param_read(iparam_list * plist, gs_param_name pkey, iparam_loc * ploc,
	       int type)
{
    iparam_list *const iplist = (iparam_list *) plist;
    ref kref;
    int code = ref_param_key(plist, pkey, &kref);

    if (code < 0)
	return code;
    code = (*plist->u.r.read) (iplist, &kref, ploc);
    if (code != 0)
	return code;
    if (type >= 0)
	iparam_check_type(*ploc, type);
    return 0;
}

/* ---------------- Implementations ---------------- */

/* Implementation for putting parameters from an empty collection. */
private int
empty_param_read(iparam_list * plist, const ref * pkey, iparam_loc * ploc)
{
    return 1;
}

/* Initialize for reading parameters. */
private int
ref_param_read_init(iparam_list * plist, uint count, const ref * ppolicies,
		    bool require_all, gs_ref_memory_t *imem)
{
    gs_param_list_init((gs_param_list *)plist, &ref_read_procs,
		       (gs_memory_t *)imem);
    plist->ref_memory = imem;
    if (ppolicies == 0)
	make_null(&plist->u.r.policies);
    else
	plist->u.r.policies = *ppolicies;
    plist->u.r.require_all = require_all;
    plist->count = count;
    plist->results = (int *)
	gs_alloc_byte_array(plist->memory, count, sizeof(int),
			    "ref_param_read_init");

    if (plist->results == 0)
	return_error(e_VMerror);
    memset(plist->results, 0, count * sizeof(int));

    plist->int_keys = false;
    return 0;
}

/* Implementation for putting parameters from an indexed array. */
private int
array_indexed_param_read(iparam_list * plist, const ref * pkey, iparam_loc * ploc)
{
    ref *const arr = &((dict_param_list *) plist)->dict;

    check_type(*pkey, t_integer);
    if (pkey->value.intval < 0 || pkey->value.intval >= r_size(arr))
	return 1;
    ploc->pvalue = arr->value.refs + pkey->value.intval;
    ploc->presult = &plist->results[pkey->value.intval];
    *ploc->presult = 1;
    return 0;
}
int
array_indexed_param_list_read(dict_param_list * plist, const ref * parray,
			      const ref * ppolicies, bool require_all,
			      gs_ref_memory_t *ref_memory)
{
    iparam_list *const iplist = (iparam_list *) plist;
    int code;

    check_read_type(*parray, t_array);
    plist->u.r.read = array_indexed_param_read;
    plist->dict = *parray;
    code = ref_param_read_init(iplist, r_size(parray), ppolicies,
			       require_all, ref_memory);
    plist->int_keys = true;
    return code;
}

/* Implementation for putting parameters from an array. */
private int
array_param_read(iparam_list * plist, const ref * pkey, iparam_loc * ploc)
{
    ref *bot = ((array_param_list *) plist)->bot;
    ref *ptr = bot;
    ref *top = ((array_param_list *) plist)->top;

    for (; ptr < top; ptr += 2) {
	if (r_has_type(ptr, t_name) && name_eq(ptr, pkey)) {
	    ploc->pvalue = ptr + 1;
	    ploc->presult = &plist->results[ptr - bot];
	    *ploc->presult = 1;
	    return 0;
	}
    }
    return 1;
}

/* Implementation for enumerating parameters in an array */
private int			/* ret 0 ok, 1 if EOF, or -ve err */
array_param_enumerate(iparam_list * plist, gs_param_enumerator_t * penum,
		      gs_param_key_t * key, ref_type * type)
{
    int index = penum->intval;
    ref *bot = ((array_param_list *) plist)->bot;
    ref *ptr = bot + index;
    ref *top = ((array_param_list *) plist)->top;

    for (; ptr < top; ptr += 2) {
	index += 2;

	if (r_has_type(ptr, t_name)) {
	    int code = ref_to_key(ptr, key, plist);

	    *type = r_type(ptr);
	    penum->intval = index;
	    return code;
	}
    }
    return 1;
}

int
array_param_list_read(array_param_list * plist, ref * bot, uint count,
		      const ref * ppolicies, bool require_all,
		      gs_ref_memory_t *imem)
{
    iparam_list *const iplist = (iparam_list *) plist;

    if (count & 1)
	return_error(e_rangecheck);
    plist->u.r.read = array_param_read;
    plist->enumerate = array_param_enumerate;
    plist->bot = bot;
    plist->top = bot + count;
    return ref_param_read_init(iplist, count, ppolicies, require_all, imem);
}

/* Implementation for putting parameters from a stack. */
private int
stack_param_read(iparam_list * plist, const ref * pkey, iparam_loc * ploc)
{
    stack_param_list *const splist = (stack_param_list *) plist;
    ref_stack_t *pstack = splist->pstack;

    /* This implementation is slow, but it probably doesn't matter. */
    uint index = splist->skip + 1;
    uint count = splist->count;

    for (; count; count--, index += 2) {
	const ref *p = ref_stack_index(pstack, index);

	if (r_has_type(p, t_name) && name_eq(p, pkey)) {
	    ploc->pvalue = ref_stack_index(pstack, index - 1);
	    ploc->presult = &plist->results[count - 1];
	    *ploc->presult = 1;
	    return 0;
	}
    }
    return 1;
}
int
stack_param_list_read(stack_param_list * plist, ref_stack_t * pstack,
		      uint skip, const ref * ppolicies, bool require_all,
		      gs_ref_memory_t *imem)
{
    iparam_list *const iplist = (iparam_list *) plist;
    uint count = ref_stack_counttomark(pstack);

    if (count == 0)
	return_error(e_unmatchedmark);
    count -= skip + 1;
    if (count & 1)
	return_error(e_rangecheck);
    plist->u.r.read = stack_param_read;
    plist->enumerate = stack_param_enumerate;
    plist->pstack = pstack;
    plist->skip = skip;
    return ref_param_read_init(iplist, count >> 1, ppolicies, require_all, imem);
}

/* Implementation for putting parameters from a dictionary. */
private int
dict_param_read(iparam_list * plist, const ref * pkey, iparam_loc * ploc)
{
    ref const *spdict = &((dict_param_list *) plist)->dict;
    int code = dict_find(spdict, pkey, &ploc->pvalue);

    if (code != 1)
	return 1;
    ploc->presult =
	&plist->results[dict_value_index(spdict, ploc->pvalue)];
    *ploc->presult = 1;
    return 0;
}
int
dict_param_list_read(dict_param_list * plist, const ref * pdict,
		     const ref * ppolicies, bool require_all,
		     gs_ref_memory_t *imem)
{
    iparam_list *const iplist = (iparam_list *) plist;
    uint count;

    if (pdict == 0) {
	plist->u.r.read = empty_param_read;
	count = 0;
    } else {
	check_dict_read(*pdict);
	plist->u.r.read = dict_param_read;
	plist->dict = *pdict;
	count = dict_max_index(pdict) + 1;
    }
    plist->enumerate = dict_param_enumerate;
    return ref_param_read_init(iplist, count, ppolicies, require_all, imem);
}
