#include <selfmt.h>
Public Member Functions | |
SelectFormat (const UnicodeString &pattern, UErrorCode &status) | |
Creates a new SelectFormat for a given pattern string. | |
SelectFormat (const SelectFormat &other) | |
copy constructor. | |
virtual | ~SelectFormat () |
Destructor. | |
void | applyPattern (const UnicodeString &pattern, UErrorCode &status) |
Sets the pattern used by this select format. | |
UnicodeString & | format (const UnicodeString &keyword, UnicodeString &appendTo, FieldPosition &pos, UErrorCode &status) const |
Selects the phrase for the given keyword. | |
SelectFormat & | operator= (const SelectFormat &other) |
Assignment operator. | |
virtual UBool | operator== (const Format &other) const |
Return true if another object is semantically equal to this one. | |
virtual UBool | operator!= (const Format &other) const |
Return true if another object is semantically unequal to this one. | |
virtual Format * | clone (void) const |
Clones this Format object polymorphically. | |
UnicodeString & | format (const Formattable &obj, UnicodeString &appendTo, FieldPosition &pos, UErrorCode &status) const |
Format an object to produce a string. | |
UnicodeString & | toPattern (UnicodeString &appendTo) |
Returns the pattern from applyPattern() or constructor. | |
virtual void | parseObject (const UnicodeString &source, Formattable &result, ParsePosition &parse_pos) const |
This method is not yet supported by SelectFormat . | |
virtual UClassID | getDynamicClassID () const |
ICU "poor man's RTTI", returns a UClassID for the actual class. | |
Static Public Member Functions | |
static UClassID | getStaticClassID (void) |
ICU "poor man's RTTI", returns a UClassID for this class. |
SelectFormat
supports the creation of internationalized messages by selecting phrases based on keywords. The pattern specifies how to map keywords to phrases and provides a default phrase. The object provided to the format method is a string that's matched against the keywords. If there is a match, the corresponding phrase is selected; otherwise, the default phrase is used.
SelectFormat
for Gender AgreementThe main use case for the select format is gender based inflection. When names or nouns are inserted into sentences, their gender can affect pronouns, verb forms, articles, and adjectives. Special care needs to be taken for the case where the gender cannot be determined. The impact varies between languages:
Some other languages have noun classes that are not related to gender, but similar in grammatical use. Some African languages have around 20 noun classes.
To enable localizers to create sentence patterns that take their language's gender dependencies into consideration, software has to provide information about the gender associated with a noun or name to MessageFormat
. Two main cases can be distinguished:
For people, natural gender information should be maintained for each person. The keywords "male", "female", "mixed" (for groups of people) and "unknown" are used.
The resulting keyword is provided to MessageFormat
as a parameter separate from the name or noun it's associated with. For example, to generate a message such as "Jean went to Paris", three separate arguments would be provided: The name of the person as argument 0, the gender of the person as argument 1, and the name of the city as argument 2. The sentence pattern for English, where the gender of the person has no impact on this simple sentence, would not refer to argument 1 at all:
{0} went to {2}.
The sentence pattern for French, where the gender of the person affects the form of the participle, uses a select format based on argument 1:
{0} est {1, select, female {allée} other {allé}} à {2}.
Patterns can be nested, so that it's possible to handle interactions of number and gender where necessary. For example, if the above sentence should allow for the names of several people to be inserted, the following sentence pattern can be used (with argument 0 the list of people's names, argument 1 the number of people, argument 2 their combined gender, and argument 3 the city name):
{0} {1, plural, one {est {2, select, female {allée} other {allé}}} other {sont {2, select, female {allées} other {allés}}} }à {3}.
The SelectFormat
pattern text defines the phrase output for each user-defined keyword. The pattern is a sequence of keyword{phrase}
clauses. Each clause assigns the phrase phrase
to the user-defined keyword
.
Keywords must match the pattern [a-zA-Z][a-zA-Z0-9_-]*; keywords that don't match this pattern result in the error code U_ILLEGAL_CHARACTER
. You always have to define a phrase for the default keyword other
; this phrase is returned when the keyword provided to the format
method matches no other keyword. If a pattern does not provide a phrase for other
, the method it's provided to returns the error U_DEFAULT_KEYWORD_MISSING
. If a pattern provides more than one phrase for the same keyword, the error U_DUPLICATE_KEYWORD
is returned.
Spaces between keyword
and {phrase}
will be ignored; spaces within {phrase}
will be preserved.
The phrase for a particular select case may contain other message format patterns. SelectFormat
preserves these so that you can use the strings produced by SelectFormat
with other formatters. If you are using SelectFormat
inside a MessageFormat
pattern, MessageFormat
will automatically evaluate the resulting format pattern. Thus, curly braces ({
, }
) are only allowed in phrases to define a nested format pattern.
Example: UErrorCode status = U_ZERO_ERROR; MessageFormat *msgFmt = new MessageFormat(UnicodeString("{0} est {1, select, female {allée} other {allé}} à Paris."), Locale("fr"), status); if (U_FAILURE(status)) { return; } FieldPosition ignore(FieldPosition::DONT_CARE); UnicodeString result; char* str1= "Kirti,female"; Formattable args1[] = {"Kirti","female"}; msgFmt->format(args1, 2, result, ignore, status); cout << "Input is " << str1 << " and result is: " << result << endl; delete msgFmt;
Produces the output:
Kirti est allée à Paris.
Definition at line 184 of file selfmt.h.
SelectFormat::SelectFormat | ( | const UnicodeString & | pattern, | |
UErrorCode & | status | |||
) |
Creates a new SelectFormat
for a given pattern string.
pattern | the pattern for this SelectFormat . errors are returned to status if the pattern is invalid. | |
status | output param set to success/failure code on exit, which must not indicate a failure before the function call. |
SelectFormat::SelectFormat | ( | const SelectFormat & | other | ) |
copy constructor.
virtual SelectFormat::~SelectFormat | ( | ) | [virtual] |
Destructor.
void SelectFormat::applyPattern | ( | const UnicodeString & | pattern, | |
UErrorCode & | status | |||
) |
Sets the pattern used by this select format.
for the keyword rules. Patterns and their interpretation are specified in the class description.
pattern | the pattern for this select format errors are returned to status if the pattern is invalid. | |
status | output param set to success/failure code on exit, which must not indicate a failure before the function call. |
virtual Format* SelectFormat::clone | ( | void | ) | const [virtual] |
UnicodeString& SelectFormat::format | ( | const Formattable & | obj, | |
UnicodeString & | appendTo, | |||
FieldPosition & | pos, | |||
UErrorCode & | status | |||
) | const [virtual] |
Format an object to produce a string.
This method handles keyword strings. If the Formattable object is not a UnicodeString
, then it returns a failing UErrorCode.
obj | A keyword string that is used to select an alternative. | |
appendTo | output parameter to receive result. Result is appended to existing contents. | |
pos | On input: an alignment field, if desired. On output: the offsets of the alignment field. | |
status | output param filled with success/failure status. |
Implements Format.
UnicodeString& SelectFormat::format | ( | const UnicodeString & | keyword, | |
UnicodeString & | appendTo, | |||
FieldPosition & | pos, | |||
UErrorCode & | status | |||
) | const |
Selects the phrase for the given keyword.
keyword | The keyword that is used to select an alternative. | |
appendTo | output parameter to receive result. result is appended to existing contents. | |
pos | On input: an alignment field, if desired. On output: the offsets of the alignment field. | |
status | output param set to success/failure code on exit, which must not indicate a failure before the function call. |
virtual UClassID SelectFormat::getDynamicClassID | ( | ) | const [virtual] |
static UClassID SelectFormat::getStaticClassID | ( | void | ) | [static] |
ICU "poor man's RTTI", returns a UClassID for this class.
Return true if another object is semantically unequal to this one.
other | the SelectFormat object to be compared with. |
SelectFormat& SelectFormat::operator= | ( | const SelectFormat & | other | ) |
Assignment operator.
other | the SelectFormat object to copy from. |
Reimplemented from Format.
Return true if another object is semantically equal to this one.
other | the SelectFormat object to be compared with. |
virtual void SelectFormat::parseObject | ( | const UnicodeString & | source, | |
Formattable & | result, | |||
ParsePosition & | parse_pos | |||
) | const [virtual] |
This method is not yet supported by SelectFormat
.
Before calling, set parse_pos.index to the offset you want to start parsing at in the source. After calling, parse_pos.index is the end of the text you parsed. If error occurs, index is unchanged.
When parsing, leading whitespace is discarded (with a successful parse), while trailing whitespace is left as is.
See Format::parseObject() for more.
source | The string to be parsed into an object. | |
result | Formattable to be set to the parse result. If parse fails, return contents are undefined. | |
parse_pos | The position to start parsing at. Upon return this param is set to the position after the last character successfully parsed. If the source is not parsed successfully, this param will remain unchanged. |
Implements Format.
UnicodeString& SelectFormat::toPattern | ( | UnicodeString & | appendTo | ) |
Returns the pattern from applyPattern() or constructor.
appendTo | output parameter to receive result. Result is appended to existing contents. |