intl/lwbrk/WordBreaker.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5 #ifndef mozilla_intl_WordBreaker_h__
   6 #define mozilla_intl_WordBreaker_h__
   7
   8 #include "nsStringFwd.h"
   9 #include <cstdint>
  10
  11 #define NS_WORDBREAKER_NEED_MORE_TEXT -1
  12
  13 namespace mozilla {
  14 namespace intl {
  15
  16 struct WordRange {
  17   uint32_t mBegin;
  18   uint32_t mEnd;
  19 };
  20
  21 class WordBreaker final {
  22  public:
  23   // WordBreaker is a utility class with only static methods. No need to
  24   // instantiate it.
  25   WordBreaker() = delete;
  26   ~WordBreaker() = delete;
  27
  28   // Find the word boundary by scanning forward and backward from aPos.
  29   //
  30   // @return WordRange where mBegin equals to the offset to first character in
  31   // the word and mEnd equals to the offset to the last character plus 1. mEnd
  32   // can be aText.Lengh() if the desired word is at the end of aText.
  33   //
  34   // If aPos is already at the end of aText or beyond, both mBegin and mEnd
  35   // equals to aText.Length().
  36   //
  37   // If setting StopAtPunctuation, even if using UAX#29 word segmenter rule,
  38   // there will be break opportunities on characters with punctuation class.
  39   enum class FindWordOptions { None, StopAtPunctuation };
  40
  41   static WordRange FindWord(
  42       const nsAString& aText, uint32_t aPos,
  43       const FindWordOptions aOptions = FindWordOptions::None);
  44
  45   // Find the next word break opportunity starting from aPos + 1. It can return
  46   // aLen if there's no break opportunity between [aPos + 1, aLen - 1].
  47   //
  48   // If aPos is already at the end of aText or beyond, i.e. aPos >= aLen, return
  49   // NS_WORDBREAKER_NEED_MORE_TEXT.
  50   //
  51   // DEPRECATED: Use WordBreakIteratorUtf16 instead.
  52   static int32_t Next(const char16_t* aText, uint32_t aLen, uint32_t aPos);
  53
  54  private:
  55   enum WordBreakClass : uint8_t {
  56     kWbClassSpace = 0,
  57     kWbClassAlphaLetter,
  58     kWbClassPunct,
  59     kWbClassHanLetter,
  60     kWbClassKatakanaLetter,
  61     kWbClassHiraganaLetter,
  62     kWbClassHWKatakanaLetter,
  63     kWbClassScriptioContinua
  64   };
  65
  66   static WordBreakClass GetClass(char16_t aChar);
  67 };
  68
  69 }  // namespace intl
  70 }  // namespace mozilla
  71
  72 #endif /* mozilla_intl_WordBreaker_h__ */