The Tor Browser: intl/icu/source/i18n/rbt.h@b8a032363ba2 (annotated)

intl/icu/source/i18n/rbt.h@b8a032363ba2 (annotated)

intl/icu/source/i18n/rbt.h

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /*
 **********************************************************************
 *   Copyright (C) 1999-2007, International Business Machines
 *   Corporation and others.  All Rights Reserved.
 **********************************************************************
 *   Date        Name        Description
 *   11/17/99    aliu        Creation.
 **********************************************************************
 */
 #ifndef RBT_H
 #define RBT_H
 #include "unicode/utypes.h"
 #if !UCONFIG_NO_TRANSLITERATION
 #include "unicode/translit.h"
 #include "unicode/utypes.h"
 #include "unicode/parseerr.h"
 #include "unicode/udata.h"
 #define U_ICUDATA_TRANSLIT U_ICUDATA_NAME U_TREE_SEPARATOR_STRING "translit"
 U_NAMESPACE_BEGIN
 class TransliterationRuleData;
 /**
  * <code>RuleBasedTransliterator</code> is a transliterator
  * that reads a set of rules in order to determine how to perform
  * translations. Rule sets are stored in resource bundles indexed by
  * name. Rules within a rule set are separated by semicolons (';').
  * To include a literal semicolon, prefix it with a backslash ('\').
  * Whitespace, as defined by <code>Character.isWhitespace()</code>,
  * is ignored. If the first non-blank character on a line is '#',
  * the entire line is ignored as a comment. </p>
  *
  * <p>Each set of rules consists of two groups, one forward, and one
  * reverse. This is a convention that is not enforced; rules for one
  * direction may be omitted, with the result that translations in
  * that direction will not modify the source text. In addition,
  * bidirectional forward-reverse rules may be specified for
  * symmetrical transformations.</p>
  *
  * <p><b>Rule syntax</b> </p>
  *
  * <p>Rule statements take one of the following forms: </p>
  *
  * <dl>
  *     <dt><code>$alefmadda=\u0622;</code></dt>
  *     <dd><strong>Variable definition.</strong> The name on the
  *         left is assigned the text on the right. In this example,
  *         after this statement, instances of the left hand name,
  *         &quot;<code>$alefmadda</code>&quot;, will be replaced by
  *         the Unicode character U+0622. Variable names must begin
  *         with a letter and consist only of letters, digits, and
  *         underscores. Case is significant. Duplicate names cause
  *         an exception to be thrown, that is, variables cannot be
  *         redefined. The right hand side may contain well-formed
  *         text of any length, including no text at all (&quot;<code>$empty=;</code>&quot;).
  *         The right hand side may contain embedded <code>UnicodeSet</code>
  *         patterns, for example, &quot;<code>$softvowel=[eiyEIY]</code>&quot;.</dd>
  *     <dd>&nbsp;</dd>
  *     <dt><code>ai&gt;$alefmadda;</code></dt>
  *     <dd><strong>Forward translation rule.</strong> This rule
  *         states that the string on the left will be changed to the
  *         string on the right when performing forward
  *         transliteration.</dd>
  *     <dt>&nbsp;</dt>
  *     <dt><code>ai<$alefmadda;</code></dt>
  *     <dd><strong>Reverse translation rule.</strong> This rule
  *         states that the string on the right will be changed to
  *         the string on the left when performing reverse
  *         transliteration.</dd>
  * </dl>
  *
  * <dl>
  *     <dt><code>ai<>$alefmadda;</code></dt>
  *     <dd><strong>Bidirectional translation rule.</strong> This
  *         rule states that the string on the right will be changed
  *         to the string on the left when performing forward
  *         transliteration, and vice versa when performing reverse
  *         transliteration.</dd>
  * </dl>
  *
  * <p>Translation rules consist of a <em>match pattern</em> and an <em>output
  * string</em>. The match pattern consists of literal characters,
  * optionally preceded by context, and optionally followed by
  * context. Context characters, like literal pattern characters,
  * must be matched in the text being transliterated. However, unlike
  * literal pattern characters, they are not replaced by the output
  * text. For example, the pattern &quot;<code>abc{def}</code>&quot;
  * indicates the characters &quot;<code>def</code>&quot; must be
  * preceded by &quot;<code>abc</code>&quot; for a successful match.
  * If there is a successful match, &quot;<code>def</code>&quot; will
  * be replaced, but not &quot;<code>abc</code>&quot;. The final '<code>}</code>'
  * is optional, so &quot;<code>abc{def</code>&quot; is equivalent to
  * &quot;<code>abc{def}</code>&quot;. Another example is &quot;<code>{123}456</code>&quot;
  * (or &quot;<code>123}456</code>&quot;) in which the literal
  * pattern &quot;<code>123</code>&quot; must be followed by &quot;<code>456</code>&quot;.
  * </p>
  *
  * <p>The output string of a forward or reverse rule consists of
  * characters to replace the literal pattern characters. If the
  * output string contains the character '<code>|</code>', this is
  * taken to indicate the location of the <em>cursor</em> after
  * replacement. The cursor is the point in the text at which the
  * next replacement, if any, will be applied. The cursor is usually
  * placed within the replacement text; however, it can actually be
  * placed into the precending or following context by using the
  * special character '<code>@</code>'. Examples:</p>
  *
  * <blockquote>
  *     <p><code>a {foo} z &gt; | @ bar; # foo -&gt; bar, move cursor
  *     before a<br>
  *     {foo} xyz &gt; bar @@|; #&nbsp;foo -&gt; bar, cursor between
  *     y and z</code></p>
  * </blockquote>
  *
  * <p><b>UnicodeSet</b></p>
  *
  * <p><code>UnicodeSet</code> patterns may appear anywhere that
  * makes sense. They may appear in variable definitions.
  * Contrariwise, <code>UnicodeSet</code> patterns may themselves
  * contain variable references, such as &quot;<code>$a=[a-z];$not_a=[^$a]</code>&quot;,
  * or &quot;<code>$range=a-z;$ll=[$range]</code>&quot;.</p>
  *
  * <p><code>UnicodeSet</code> patterns may also be embedded directly
  * into rule strings. Thus, the following two rules are equivalent:</p>
  *
  * <blockquote>
  *     <p><code>$vowel=[aeiou]; $vowel&gt;'*'; # One way to do this<br>
  *     [aeiou]&gt;'*';
  *     &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#
  *     Another way</code></p>
  * </blockquote>
  *
  * <p>See {@link UnicodeSet} for more documentation and examples.</p>
  *
  * <p><b>Segments</b></p>
  *
  * <p>Segments of the input string can be matched and copied to the
  * output string. This makes certain sets of rules simpler and more
  * general, and makes reordering possible. For example:</p>
  *
  * <blockquote>
  *     <p><code>([a-z]) &gt; $1 $1;
  *     &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#
  *     double lowercase letters<br>
  *     ([:Lu:]) ([:Ll:]) &gt; $2 $1; # reverse order of Lu-Ll pairs</code></p>
  * </blockquote>
  *
  * <p>The segment of the input string to be copied is delimited by
  * &quot;<code>(</code>&quot; and &quot;<code>)</code>&quot;. Up to
  * nine segments may be defined. Segments may not overlap. In the
  * output string, &quot;<code>$1</code>&quot; through &quot;<code>$9</code>&quot;
  * represent the input string segments, in left-to-right order of
  * definition.</p>
  *
  * <p><b>Anchors</b></p>
  *
  * <p>Patterns can be anchored to the beginning or the end of the text. This is done with the
  * special characters '<code>^</code>' and '<code>$</code>'. For example:</p>
  *
  * <blockquote>
  *   <p><code>^ a&nbsp;&nbsp; &gt; 'BEG_A'; &nbsp;&nbsp;# match 'a' at start of text<br>
  *   &nbsp; a&nbsp;&nbsp; &gt; 'A';&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; # match other instances
  *   of 'a'<br>
  *   &nbsp; z $ &gt; 'END_Z'; &nbsp;&nbsp;# match 'z' at end of text<br>
  *   &nbsp; z&nbsp;&nbsp; &gt; 'Z';&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; # match other instances
  *   of 'z'</code></p>
  * </blockquote>
  *
  * <p>It is also possible to match the beginning or the end of the text using a <code>UnicodeSet</code>.
  * This is done by including a virtual anchor character '<code>$</code>' at the end of the
  * set pattern. Although this is usually the match chafacter for the end anchor, the set will
  * match either the beginning or the end of the text, depending on its placement. For
  * example:</p>
  *
  * <blockquote>
  *   <p><code>$x = [a-z$]; &nbsp;&nbsp;# match 'a' through 'z' OR anchor<br>
  *   $x 1&nbsp;&nbsp;&nbsp; &gt; 2;&nbsp;&nbsp; # match '1' after a-z or at the start<br>
  *   &nbsp;&nbsp; 3 $x &gt; 4; &nbsp;&nbsp;# match '3' before a-z or at the end</code></p>
  * </blockquote>
  *
  * <p><b>Example</b> </p>
  *
  * <p>The following example rules illustrate many of the features of
  * the rule language. </p>
  *
  * <table border="0" cellpadding="4">
  *     <tr>
  *         <td valign="top">Rule 1.</td>
  *         <td valign="top" nowrap><code>abc{def}&gt;x|y</code></td>
  *     </tr>
  *     <tr>
  *         <td valign="top">Rule 2.</td>
  *         <td valign="top" nowrap><code>xyz&gt;r</code></td>
  *     </tr>
  *     <tr>
  *         <td valign="top">Rule 3.</td>
  *         <td valign="top" nowrap><code>yz&gt;q</code></td>
  *     </tr>
  * </table>
  *
  * <p>Applying these rules to the string &quot;<code>adefabcdefz</code>&quot;
  * yields the following results: </p>
  *
  * <table border="0" cellpadding="4">
  *     <tr>
  *         <td valign="top" nowrap><code>|adefabcdefz</code></td>
  *         <td valign="top">Initial state, no rules match. Advance
  *         cursor.</td>
  *     </tr>
  *     <tr>
  *         <td valign="top" nowrap><code>a|defabcdefz</code></td>
  *         <td valign="top">Still no match. Rule 1 does not match
  *         because the preceding context is not present.</td>
  *     </tr>
  *     <tr>
  *         <td valign="top" nowrap><code>ad|efabcdefz</code></td>
  *         <td valign="top">Still no match. Keep advancing until
  *         there is a match...</td>
  *     </tr>
  *     <tr>
  *         <td valign="top" nowrap><code>ade|fabcdefz</code></td>
  *         <td valign="top">...</td>
  *     </tr>
  *     <tr>
  *         <td valign="top" nowrap><code>adef|abcdefz</code></td>
  *         <td valign="top">...</td>
  *     </tr>
  *     <tr>
  *         <td valign="top" nowrap><code>adefa|bcdefz</code></td>
  *         <td valign="top">...</td>
  *     </tr>
  *     <tr>
  *         <td valign="top" nowrap><code>adefab|cdefz</code></td>
  *         <td valign="top">...</td>
  *     </tr>
  *     <tr>
  *         <td valign="top" nowrap><code>adefabc|defz</code></td>
  *         <td valign="top">Rule 1 matches; replace &quot;<code>def</code>&quot;
  *         with &quot;<code>xy</code>&quot; and back up the cursor
  *         to before the '<code>y</code>'.</td>
  *     </tr>
  *     <tr>
  *         <td valign="top" nowrap><code>adefabcx|yz</code></td>
  *         <td valign="top">Although &quot;<code>xyz</code>&quot; is
  *         present, rule 2 does not match because the cursor is
  *         before the '<code>y</code>', not before the '<code>x</code>'.
  *         Rule 3 does match. Replace &quot;<code>yz</code>&quot;
  *         with &quot;<code>q</code>&quot;.</td>
  *     </tr>
  *     <tr>
  *         <td valign="top" nowrap><code>adefabcxq|</code></td>
  *         <td valign="top">The cursor is at the end;
  *         transliteration is complete.</td>
  *     </tr>
  * </table>
  *
  * <p>The order of rules is significant. If multiple rules may match
  * at some point, the first matching rule is applied. </p>
  *
  * <p>Forward and reverse rules may have an empty output string.
  * Otherwise, an empty left or right hand side of any statement is a
  * syntax error. </p>
  *
  * <p>Single quotes are used to quote any character other than a
  * digit or letter. To specify a single quote itself, inside or
  * outside of quotes, use two single quotes in a row. For example,
  * the rule &quot;<code>'&gt;'&gt;o''clock</code>&quot; changes the
  * string &quot;<code>&gt;</code>&quot; to the string &quot;<code>o'clock</code>&quot;.
  * </p>
  *
  * <p><b>Notes</b> </p>
  *
  * <p>While a RuleBasedTransliterator is being built, it checks that
  * the rules are added in proper order. For example, if the rule
  * &quot;a&gt;x&quot; is followed by the rule &quot;ab&gt;y&quot;,
  * then the second rule will throw an exception. The reason is that
  * the second rule can never be triggered, since the first rule
  * always matches anything it matches. In other words, the first
  * rule <em>masks</em> the second rule. </p>
  *
  * @author Alan Liu
  * @internal Use transliterator factory methods instead since this class will be removed in that release.
  */
 class RuleBasedTransliterator : public Transliterator {
 private:
     /**
      * The data object is immutable, so we can freely share it with
      * other instances of RBT, as long as we do NOT own this object.
      *  TODO:  data is no longer immutable.  See bugs #1866, 2155
      */
     TransliterationRuleData* fData;
     /**
      * If true, we own the data object and must delete it.
      */
     UBool isDataOwned;
 public:
     /**
      * Constructs a new transliterator from the given rules.
      * @param rules rules, separated by ';'
      * @param direction either FORWARD or REVERSE.
      * @exception IllegalArgumentException if rules are malformed.
      * @internal Use transliterator factory methods instead since this class will be removed in that release.
      */
     RuleBasedTransliterator(const UnicodeString& id,
                             const UnicodeString& rules,
                             UTransDirection direction,
                             UnicodeFilter* adoptedFilter,
                             UParseError& parseError,
                             UErrorCode& status);
     /**
      * Constructs a new transliterator from the given rules.
      * @param rules rules, separated by ';'
      * @param direction either FORWARD or REVERSE.
      * @exception IllegalArgumentException if rules are malformed.
      * @internal Use transliterator factory methods instead since this class will be removed in that release.
      */
     /*RuleBasedTransliterator(const UnicodeString& id,
                             const UnicodeString& rules,
                             UTransDirection direction,
                             UnicodeFilter* adoptedFilter,
                             UErrorCode& status);*/
     /**
      * Covenience constructor with no filter.
      * @internal Use transliterator factory methods instead since this class will be removed in that release.
      */
     /*RuleBasedTransliterator(const UnicodeString& id,
                             const UnicodeString& rules,
                             UTransDirection direction,
                             UErrorCode& status);*/
     /**
      * Covenience constructor with no filter and FORWARD direction.
      * @internal Use transliterator factory methods instead since this class will be removed in that release.
      */
     /*RuleBasedTransliterator(const UnicodeString& id,
                             const UnicodeString& rules,
                             UErrorCode& status);*/
     /**
      * Covenience constructor with FORWARD direction.
      * @internal Use transliterator factory methods instead since this class will be removed in that release.
      */
     /*RuleBasedTransliterator(const UnicodeString& id,
                             const UnicodeString& rules,
                             UnicodeFilter* adoptedFilter,
                             UErrorCode& status);*/
 private:
      friend class TransliteratorRegistry; // to access TransliterationRuleData convenience ctor
     /**
      * Covenience constructor.
      * @param id            the id for the transliterator.
      * @param theData       the rule data for the transliterator.
      * @param adoptedFilter the filter for the transliterator
      */
     RuleBasedTransliterator(const UnicodeString& id,
                             const TransliterationRuleData* theData,
                             UnicodeFilter* adoptedFilter = 0);
     friend class Transliterator; // to access following ct
     /**
      * Internal constructor.
      * @param id            the id for the transliterator.
      * @param theData       the rule data for the transliterator.
      * @param isDataAdopted determine who will own the 'data' object. True, the caller should not delete 'data'.
      */
     RuleBasedTransliterator(const UnicodeString& id,
                             TransliterationRuleData* data,
                             UBool isDataAdopted);
 public:
     /**
      * Copy constructor.
      * @internal Use transliterator factory methods instead since this class will be removed in that release.
      */
     RuleBasedTransliterator(const RuleBasedTransliterator&);
     virtual ~RuleBasedTransliterator();
     /**
      * Implement Transliterator API.
      * @internal Use transliterator factory methods instead since this class will be removed in that release.
      */
     virtual Transliterator* clone(void) const;
 protected:
     /**
      * Implements {@link Transliterator#handleTransliterate}.
      * @internal Use transliterator factory methods instead since this class will be removed in that release.
      */
     virtual void handleTransliterate(Replaceable& text, UTransPosition& offsets,
                                      UBool isIncremental) const;
 public:
     /**
      * Return a representation of this transliterator as source rules.
      * These rules will produce an equivalent transliterator if used
      * to construct a new transliterator.
      * @param result the string to receive the rules.  Previous
      * contents will be deleted.
      * @param escapeUnprintable if TRUE then convert unprintable
      * character to their hex escape representations, \uxxxx or
      * \Uxxxxxxxx.  Unprintable characters are those other than
      * U+000A, U+0020..U+007E.
      * @internal Use transliterator factory methods instead since this class will be removed in that release.
      */
     virtual UnicodeString& toRules(UnicodeString& result,
                                    UBool escapeUnprintable) const;
 protected:
     /**
      * Implement Transliterator framework
      */
     virtual void handleGetSourceSet(UnicodeSet& result) const;
 public:
     /**
      * Override Transliterator framework
      */
     virtual UnicodeSet& getTargetSet(UnicodeSet& result) const;
     /**
      * Return the class ID for this class.  This is useful only for
      * comparing to a return value from getDynamicClassID().  For example:
      * <pre>
      * .      Base* polymorphic_pointer = createPolymorphicObject();
      * .      if (polymorphic_pointer->getDynamicClassID() ==
      * .          Derived::getStaticClassID()) ...
      * </pre>
      * @return          The class ID for all objects of this class.
      * @internal Use transliterator factory methods instead since this class will be removed in that release.
      */
     U_I18N_API static UClassID U_EXPORT2 getStaticClassID(void);
     /**
      * Returns a unique class ID <b>polymorphically</b>.  This method
      * is to implement a simple version of RTTI, since not all C++
      * compilers support genuine RTTI.  Polymorphic operator==() and
      * clone() methods call this method.
      *
      * @return The class ID for this object. All objects of a given
      * class have the same class ID.  Objects of other classes have
      * different class IDs.
      */
     virtual UClassID getDynamicClassID(void) const;
 private:
     void _construct(const UnicodeString& rules,
                     UTransDirection direction,
                     UParseError& parseError,
                     UErrorCode& status);
 };
 U_NAMESPACE_END
 #endif /* #if !UCONFIG_NO_TRANSLITERATION */
 #endif

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intl/icu/source/i18n/rbt.h@b8a032363ba2 (annotated)

intl/icu/source/i18n/rbt.h