icuSources/i18n/unicode/unirepl.h

   1 /*
   2 **********************************************************************
   3 *   Copyright (c) 2002-2004, International Business Machines Corporation
   4 *   and others.  All Rights Reserved.
   5 **********************************************************************
   6 *   Date        Name        Description
   7 *   01/14/2002  aliu        Creation.
   8 **********************************************************************
   9 */
  10 #ifndef UNIREPL_H
  11 #define UNIREPL_H
  12
  13 #include "unicode/utypes.h"
  14
  15 U_NAMESPACE_BEGIN
  16
  17 class Replaceable;
  18 class UnicodeString;
  19 class UnicodeSet;
  20
  21 /**
  22  * <code>UnicodeReplacer</code> defines a protocol for objects that
  23  * replace a range of characters in a Replaceable string with output
  24  * text.  The replacement is done via the Replaceable API so as to
  25  * preserve out-of-band data.
  26  *
  27  * <p>This is a mixin class.
  28  * @author Alan Liu
  29  * @stable ICU 2.4
  30  */
  31 class U_I18N_API UnicodeReplacer /* not : public UObject because this is an interface/mixin class */ {
  32
  33  public:
  34
  35     /**
  36      * Destructor.
  37      * @stable ICU 2.4
  38      */
  39     virtual ~UnicodeReplacer();
  40
  41     /**
  42      * Replace characters in 'text' from 'start' to 'limit' with the
  43      * output text of this object.  Update the 'cursor' parameter to
  44      * give the cursor position and return the length of the
  45      * replacement text.
  46      *
  47      * @param text the text to be matched
  48      * @param start inclusive start index of text to be replaced
  49      * @param limit exclusive end index of text to be replaced;
  50      * must be greater than or equal to start
  51      * @param cursor output parameter for the cursor position.
  52      * Not all replacer objects will update this, but in a complete
  53      * tree of replacer objects, representing the entire output side
  54      * of a transliteration rule, at least one must update it.
  55      * @return the number of 16-bit code units in the text replacing
  56      * the characters at offsets start..(limit-1) in text
  57      * @stable ICU 2.4
  58      */
  59     virtual int32_t replace(Replaceable& text,
  60                             int32_t start,
  61                             int32_t limit,
  62                             int32_t& cursor) = 0;
  63
  64     /**
  65      * Returns a string representation of this replacer.  If the
  66      * result of calling this function is passed to the appropriate
  67      * parser, typically TransliteratorParser, it will produce another
  68      * replacer that is equal to this one.
  69      * @param result the string to receive the pattern.  Previous
  70      * contents will be deleted.
  71      * @param escapeUnprintable if TRUE then convert unprintable
  72      * character to their hex escape representations, \\uxxxx or
  73      * \\Uxxxxxxxx.  Unprintable characters are defined by
  74      * Utility.isUnprintable().
  75      * @return a reference to 'result'.
  76      * @stable ICU 2.4
  77      */
  78     virtual UnicodeString& toReplacerPattern(UnicodeString& result,
  79                                              UBool escapeUnprintable) const = 0;
  80
  81     /**
  82      * Union the set of all characters that may output by this object
  83      * into the given set.
  84      * @param toUnionTo the set into which to union the output characters
  85      * @stable ICU 2.4
  86      */
  87     virtual void addReplacementSetTo(UnicodeSet& toUnionTo) const = 0;
  88 };
  89
  90 U_NAMESPACE_END
  91
  92 #endif