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icu46/source/i18n/unicode/selfmt.h

+/********************************************************************
+ * COPYRIGHT:
+ * Copyright (c) 1997-2010, International Business Machines Corporation and
+ * others. All Rights Reserved.
+ * Copyright (C) 2010 , Yahoo! Inc.
+ ********************************************************************
+ *
+ * File SELFMT.H
+ *
+ * Modification History:
+ *
+ *   Date        Name        Description
+ *   11/11/09    kirtig      Finished first cut of implementation.
+ ********************************************************************/
+
+#ifndef SELFMT
+#define SELFMT
+
+#include "unicode/utypes.h"
+#include "unicode/numfmt.h"
+
+/**
+ * \file
+ * \brief C++ API: SelectFormat object
+ */
+
+#if !UCONFIG_NO_FORMATTING
+
+U_NAMESPACE_BEGIN
+
+class Hashtable;
+
+/**
+  * <p><code>SelectFormat</code> 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.</p>
+  *
+  * <h4>Using <code>SelectFormat</code> for Gender Agreement</h4>
+  *
+  * <p>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:</p>
+  * \htmlonly
+  * <ul>
+  * <li>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".
+  *
+  * <li>German differs from English in that the gender of nouns is  rather
+  * arbitrary, even for nouns referring to people ("M&#x00E4;dchen", girl, is  neutral).
+  * The gender affects pronouns ("er", "sie", "es"), articles ("der",  "die",
+  * "das"), and adjective forms ("guter Mann", "gute Frau", "gutes  M&#x00E4;dchen").
+  *
+  * <li>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 ("all&#x00E9;", "all&#x00E9;e").
+  *
+  * <li>Polish distinguishes five genders (or noun classes),
+  * human masculine, animate non-human masculine, inanimate masculine,
+  * feminine, and neuter.
+  * </ul>
+  * \endhtmlonly
+  * <p>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.</p>
+  *
+  * <p>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
+  * <code>MessageFormat</code>.
+  * Two main cases can be distinguished:</p>
+  *
+  * <ul>
+  * <li>For people, natural gender information should be maintained  for each person.
+  * The keywords "male", "female", "mixed" (for groups of people)
+  * and "unknown" are used.
+  *
+  * <li>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.
+  * </ul>
+  *
+  * <p>The resulting keyword is provided to <code>MessageFormat</code>  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:</p>
+  *
+  * <pre>{0} went to {2}.</pre>
+  *
+  * <p>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:</p>
+  *
+  * \htmlonly<pre>{0} est {1, select, female {all&#x00E9;e} other {all&#x00E9;}} &#x00E0; {2}.</pre>\endhtmlonly
+  *
+  * <p>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):</p>
+  *
+  * \htmlonly
+  * <pre>{0} {1, plural,
+  *                 one {est {2, select, female {all&#x00E9;e} other  {all&#x00E9;}}}
+  *                 other {sont {2, select, female {all&#x00E9;es} other {all&#x00E9;s}}}
+  *          }&#x00E0; {3}.</pre>
+  * \endhtmlonly
+  *
+  * <h4>Patterns and Their Interpretation</h4>
+  *
+  * <p>The <code>SelectFormat</code> pattern text defines the phrase  output
+  * for each user-defined keyword.
+  * The pattern is a sequence of <code><i>keyword</i>{<i>phrase</i>}</code>
+  * clauses.
+  * Each clause assigns the phrase <code><i>phrase</i></code>
+  * to the user-defined <code><i>keyword</i></code>.</p>
+  *
+  * <p>Keywords must match the pattern [a-zA-Z][a-zA-Z0-9_-]*; keywords
+  * that don't match this pattern result in the error code
+  * <code>U_ILLEGAL_CHARACTER</code>.
+  * You always have to define a phrase for the default keyword
+  * <code>other</code>; this phrase is returned when the keyword
+  * provided to
+  * the <code>format</code> method matches no other keyword.
+  * If a pattern does not provide a phrase for <code>other</code>, the  method
+  * it's provided to returns the error  <code>U_DEFAULT_KEYWORD_MISSING</code>.
+  * If a pattern provides more than one phrase for the same keyword, the
+  * error <code>U_DUPLICATE_KEYWORD</code> is returned.
+  * <br>
+  * Spaces between <code><i>keyword</i></code> and
+  * <code>{<i>phrase</i>}</code>  will be ignored; spaces within
+  * <code>{<i>phrase</i>}</code> will be preserved.<p>
+  *
+  * <p>The phrase for a particular select case may contain other message
+  * format patterns. <code>SelectFormat</code> preserves these so that  you
+  * can use the strings produced by <code>SelectFormat</code> with other
+  * formatters. If you are using <code>SelectFormat</code> inside a
+  * <code>MessageFormat</code> pattern, <code>MessageFormat</code> will
+  * automatically evaluate the resulting format pattern.
+  * Thus, curly braces (<code>{</code>, <code>}</code>) are <i>only</i> allowed
+  * in phrases to define a nested format pattern.</p>
+  *
+  * <p>Example:
+  * \htmlonly
+  *
+  * UErrorCode status = U_ZERO_ERROR;
+  * MessageFormat *msgFmt = new MessageFormat(UnicodeString("{0} est  {1, select, female {all&#x00E9;e} other {all&#x00E9;}} &#x00E0; 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;
+  *
+  * \endhtmlonly
+  * </p>
+  *
+  * Produces the output:<br>
+  * \htmlonly
+  * <code>Kirti est all&#x00E9;e &#x00E0; Paris.</code>
+  * \endhtmlonly
+  *
+  * @stable ICU 4.4
+  */
+
+class U_I18N_API SelectFormat : public Format {
+public:
+
+    /**
+     * Creates a new <code>SelectFormat</code> for a given pattern string.
+     * @param  pattern the pattern for this <code>SelectFormat</code>.
+     *                 errors are returned to status if the pattern is invalid.
+     * @param status   output param set to success/failure code on exit, which
+     *                 must not indicate a failure before the function call.
+     * @stable ICU 4.4
+     */
+    SelectFormat(const UnicodeString& pattern, UErrorCode& status);
+
+    /**
+     * copy constructor.
+     * @stable ICU 4.4
+     */
+    SelectFormat(const SelectFormat& other);
+
+    /**
+     * Destructor.
+     * @stable ICU 4.4
+     */
+    virtual ~SelectFormat();
+
+    /**
+     * Sets the pattern used by this select format.
+     * for the keyword rules.
+     * Patterns and their interpretation are specified in the class description.
+     *
+     * @param pattern the pattern for this select format
+     *                errors are returned to status if the pattern is invalid.
+     * @param status  output param set to success/failure code on exit, which
+     *                must not indicate a failure before the function call.
+     * @stable ICU 4.4
+     */
+    void applyPattern(const UnicodeString& pattern, UErrorCode& status);
+
+
+    using Format::format;
+
+    /**
+     * Selects the phrase for  the given keyword
+     *
+     * @param keyword  The keyword that is used to select an alternative.
+     * @param appendTo output parameter to receive result.
+     *                 result is appended to existing contents.
+     * @param pos      On input: an alignment field, if desired.
+     *                 On output: the offsets of the alignment field.
+     * @param status  output param set to success/failure code on exit, which
+     *                 must not indicate a failure before the function call.
+     * @return         Reference to 'appendTo' parameter.
+     * @stable ICU 4.4
+     */
+    UnicodeString& format(const UnicodeString& keyword,
+                            UnicodeString& appendTo,
+                            FieldPosition& pos,
+                            UErrorCode& status) const;
+
+    /**
+     * Assignment operator
+     *
+     * @param other    the SelectFormat object to copy from.
+     * @stable ICU 4.4
+     */
+    SelectFormat& operator=(const SelectFormat& other);
+
+    /**
+     * Return true if another object is semantically equal to this one.
+     *
+     * @param other    the SelectFormat object to be compared with.
+     * @return         true if other is semantically equal to this.
+     * @stable ICU 4.4
+     */
+    virtual UBool operator==(const Format& other) const;
+
+    /**
+     * Return true if another object is semantically unequal to this one.
+     *
+     * @param other    the SelectFormat object to be compared with.
+     * @return         true if other is semantically unequal to this.
+     * @stable ICU 4.4
+     */
+    virtual UBool operator!=(const Format& other) const;
+
+    /**
+     * Clones this Format object polymorphically.  The caller owns the
+     * result and should delete it when done.
+     * @stable ICU 4.4
+     */
+    virtual Format* clone(void) const;
+
+    /**
+     * Format an object to produce a string.
+     * This method handles keyword strings.
+     * If the Formattable object is not a <code>UnicodeString</code>,
+     * then it returns a failing UErrorCode.
+     *
+     * @param obj       A keyword string that is used to select an alternative.
+     * @param appendTo  output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @param pos       On input: an alignment field, if desired.
+     *                  On output: the offsets of the alignment field.
+     * @param status    output param filled with success/failure status.
+     * @return          Reference to 'appendTo' parameter.
+     * @stable ICU 4.4
+     */
+    UnicodeString& format(const Formattable& obj,
+                         UnicodeString& appendTo,
+                         FieldPosition& pos,
+                         UErrorCode& status) const;
+
+    /**
+     * Returns the pattern from applyPattern() or constructor.
+     *
+     * @param  appendTo  output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @return the UnicodeString with inserted pattern.
+     * @stable ICU 4.4
+     */
+    UnicodeString& toPattern(UnicodeString& appendTo);
+
+    /**
+     * This method is not yet supported by <code>SelectFormat</code>.
+     * <P>
+     * 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.
+     * <P>
+     * When parsing, leading whitespace is discarded (with a successful parse),
+     * while trailing whitespace is left as is.
+     * <P>
+     * See Format::parseObject() for more.
+     *
+     * @param source     The string to be parsed into an object.
+     * @param result     Formattable to be set to the parse result.
+     *     If parse fails, return contents are undefined.
+     * @param 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.
+     * @stable ICU 4.4
+     */
+    virtual void parseObject(const UnicodeString& source,
+                            Formattable& result,
+                            ParsePosition& parse_pos) const;
+
+    /**
+     * ICU "poor man's RTTI", returns a UClassID for this class.
+     * @stable ICU 4.4
+     */
+    static UClassID U_EXPORT2 getStaticClassID(void);
+
+    /**
+     * ICU "poor man's RTTI", returns a UClassID for the actual class.
+     * @stable ICU 4.4
+     */
+    virtual UClassID getDynamicClassID() const;
+
+private:
+    typedef enum classesForSelectFormat{
+        tStartKeyword,
+        tContinueKeyword,
+        tLeftBrace,
+        tRightBrace,
+        tSpace,
+        tOther
+    }CharacterClass;
+
+    UnicodeString pattern;
+    //Hash to store the keyword, phrase pairs.
+    Hashtable  *parsedValuesHash;
+
+    SelectFormat();   // default constructor not implemented.
+    void initHashTable(UErrorCode &status);
+    void cleanHashTable();
+
+    //For the applyPattern , classifies char.s in one of the characterClass.
+    CharacterClass classifyCharacter(UChar ch) const;
+    //Checks if the "other" keyword is present in pattern.
+    UBool checkSufficientDefinition();
+    //Checks if the keyword passed is valid.
+    UBool checkValidKeyword(const UnicodeString& argKeyword) const;
+    void parsingFailure();
+    void copyHashtable(Hashtable *other, UErrorCode& status);
+};
+
+U_NAMESPACE_END
+
+#endif /* #if !UCONFIG_NO_FORMATTING */
+
+#endif // _SELFMT
+//eof