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/*
 *******************************************************************************
 * Copyright (C) 2004-2016, International Business Machines Corporation and    *
 * others. All Rights Reserved.                                                *
 * Copyright (C) 2009 , Yahoo! Inc.                                            *
 *******************************************************************************
 */
package com.ibm.icu.text;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.text.FieldPosition;
import java.text.Format;
import java.text.ParsePosition;

import com.ibm.icu.impl.PatternProps;

/**
 * 

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. * *

Using SelectFormat for Gender Agreement

* *

Note: Typically, select formatting is done via MessageFormat * with a select argument type, * rather than using a stand-alone SelectFormat. * *

The 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: * *

    *
  • English has three genders, and unknown gender is handled as a special * case. Names use the gender of the named person (if known), nouns referring * to people use natural gender, and inanimate objects are usually neutral. * The gender only affects pronouns: "he", "she", "it", "they". * *
  • German differs from English in that the gender of nouns is rather * arbitrary, even for nouns referring to people ("Mädchen", girl, is neutral). * The gender affects pronouns ("er", "sie", "es"), articles ("der", "die", * "das"), and adjective forms ("guter Mann", "gute Frau", "gutes Mädchen"). * *
  • French has only two genders; as in German the gender of nouns * is rather arbitrary - for sun and moon, the genders * are the opposite of those in German. The gender affects * pronouns ("il", "elle"), articles ("le", "la"), * adjective forms ("bon", "bonne"), and sometimes * verb forms ("allé", "allée"). * *
  • Polish distinguishes five genders (or noun classes), * human masculine, animate non-human masculine, inanimate masculine, * feminine, and neuter. *
* *

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. * *

Note:For the gender of a person in a given sentence, * we usually need to distinguish only between female, male and other/unknown. * *

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. * Keywords like "male", "female", "mixed" (for groups of people) * and "unknown" could be used. * *
  • For nouns, grammatical gender information should be maintained for * each noun and per language, e.g., in resource bundles. * The keywords "masculine", "feminine", and "neuter" are commonly used, * but some languages may require other keywords. *
* *

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}.
* *

Note: The entire sentence should be included (and partially repeated) * inside each phrase. Otherwise translators would have to be trained on how to * move bits of the sentence in and out of the select argument of a message. * (The examples below do not follow this recommendation!) * *

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}.
* *

Patterns and Their Interpretation

* *

The SelectFormat pattern string defines the phrase output * for each user-defined keyword. * The pattern is a sequence of (keyword, message) pairs. * A keyword is a "pattern identifier": [^[[:Pattern_Syntax:][:Pattern_White_Space:]]]+ * *

Each message is a MessageFormat pattern string enclosed in {curly braces}. * *

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. *
* Pattern_White_Space between keywords and messages is ignored. * Pattern_White_Space within a message is preserved and output. * *

Example:
 * MessageFormat msgFmt = new MessageFormat("{0} est " +
 *     "{1, select, female {allée} other {allé}} à Paris.",
 *     new ULocale("fr"));
 * Object args[] = {"Kirti","female"};
 * System.out.println(msgFmt.format(args));
 * 
*

* Produces the output:
* Kirti est allée à Paris. * * @stable ICU 4.4 */ public class SelectFormat extends Format{ // Generated by serialver from JDK 1.5 private static final long serialVersionUID = 2993154333257524984L; /* * The applied pattern string. */ private String pattern = null; /** * The MessagePattern which contains the parsed structure of the pattern string. */ transient private MessagePattern msgPattern; /** * Creates a new SelectFormat for a given pattern string. * @param pattern the pattern for this SelectFormat. * @stable ICU 4.4 */ public SelectFormat(String pattern) { applyPattern(pattern); } /* * Resets the SelectFormat object. */ private void reset() { pattern = null; if(msgPattern != null) { msgPattern.clear(); } } /** * Sets the pattern used by this select format. * Patterns and their interpretation are specified in the class description. * * @param pattern the pattern for this select format. * @throws IllegalArgumentException when the pattern is not a valid select format pattern. * @stable ICU 4.4 */ public void applyPattern(String pattern) { this.pattern = pattern; if (msgPattern == null) { msgPattern = new MessagePattern(); } try { msgPattern.parseSelectStyle(pattern); } catch(RuntimeException e) { reset(); throw e; } } /** * Returns the pattern for this SelectFormat * * @return the pattern string * @stable ICU 4.4 */ public String toPattern() { return pattern; } /** * Finds the SelectFormat sub-message for the given keyword, or the "other" sub-message. * @param pattern A MessagePattern. * @param partIndex the index of the first SelectFormat argument style part. * @param keyword a keyword to be matched to one of the SelectFormat argument's keywords. * @return the sub-message start part index. */ /*package*/ static int findSubMessage(MessagePattern pattern, int partIndex, String keyword) { int count=pattern.countParts(); int msgStart=0; // Iterate over (ARG_SELECTOR, message) pairs until ARG_LIMIT or end of select-only pattern. do { MessagePattern.Part part=pattern.getPart(partIndex++); MessagePattern.Part.Type type=part.getType(); if(type==MessagePattern.Part.Type.ARG_LIMIT) { break; } assert type==MessagePattern.Part.Type.ARG_SELECTOR; // part is an ARG_SELECTOR followed by a message if(pattern.partSubstringMatches(part, keyword)) { // keyword matches return partIndex; } else if(msgStart==0 && pattern.partSubstringMatches(part, "other")) { msgStart=partIndex; } partIndex=pattern.getLimitPartIndex(partIndex); } while(++partIndexStringBuffer
. * @param keyword a phrase selection keyword. * @param toAppendTo the selected phrase will be appended to this * StringBuffer. * @param pos will be ignored by this method. * @throws IllegalArgumentException when the given keyword is not a String * or not a "pattern identifier" * @return the string buffer passed in as toAppendTo, with formatted text * appended. * @stable ICU 4.4 */ public StringBuffer format(Object keyword, StringBuffer toAppendTo, FieldPosition pos) { if (keyword instanceof String) { toAppendTo.append(format( (String)keyword)); }else{ throw new IllegalArgumentException("'" + keyword + "' is not a String"); } return toAppendTo; } /** * This method is not supported by SelectFormat. * @param source the string to be parsed. * @param pos defines the position where parsing is to begin, * and upon return, the position where parsing left off. If the position * has not changed upon return, then parsing failed. * @return nothing because this method is not supported. * @throws UnsupportedOperationException thrown always. * @stable ICU 4.4 */ public Object parseObject(String source, ParsePosition pos) { throw new UnsupportedOperationException(); } /** * {@inheritDoc} * @stable ICU 4.4 */ @Override public boolean equals(Object obj) { if(this == obj) { return true; } if(obj == null || getClass() != obj.getClass()) { return false; } SelectFormat sf = (SelectFormat) obj; return msgPattern == null ? sf.msgPattern == null : msgPattern.equals(sf.msgPattern); } /** * {@inheritDoc} * @stable ICU 4.4 */ @Override public int hashCode() { if (pattern != null) { return pattern.hashCode(); } return 0; } /** * {@inheritDoc} * @stable ICU 4.4 */ @Override public String toString() { return "pattern='" + pattern + "'"; } private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException { in.defaultReadObject(); if (pattern != null) { applyPattern(pattern); } } }





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