Class ScriptScanner

cld2/internal/getonescriptspan.h:49–105

class ScriptScanner {
 public:
  ScriptScanner(const char* buffer, int buffer_length, bool is_plain_text);
  ScriptScanner(const char* buffer, int buffer_length, bool is_plain_text,
                bool any_text, bool any_script);
  ~ScriptScanner();

  // Copy next run of same-script non-tag letters to buffer [NUL terminated]
  bool GetOneScriptSpan(LangSpan* span);

  // Force Latin and Cyrillic scripts to be lowercase
  void LowerScriptSpan(LangSpan* span);

  // Copy next run of same-script non-tag letters to buffer [NUL terminated]
  // Force Latin and Cyrillic scripts to be lowercase
  bool GetOneScriptSpanLower(LangSpan* span);

  // Copy next run of non-tag characters to buffer [NUL terminated]
  // This just removes tags and removes entities
  // Buffer has leading space
  bool GetOneTextSpan(LangSpan* span);

  // Maps byte offset in most recent GetOneScriptSpan/Lower
  // span->text [0..text_bytes] into an additional byte offset from
  // span->offset, to get back to corresponding text in the original
  // input buffer.
  // text_offset must be the first byte
  // of a UTF-8 character, or just beyond the last character. Normally this
  // routine is called with the first byte of an interesting range and
  // again with the first byte of the following range.
  int MapBack(int text_offset);

  const char* GetBufferStart() {return start_byte_;};

 private:
  // Skip over tags and non-letters
  int SkipToFrontOfSpan(const char* src, int len, int* script);

  const char* start_byte_;        // Starting byte of buffer to scan
  const char* next_byte_;         // First unscanned byte
  const char* next_byte_limit_;   // Last byte + 1
  int byte_length_;               // Bytes left: next_byte_limit_ - next_byte_

  bool is_plain_text_;            // true fo text, false for HTML
  char* script_buffer_;           // Holds text with expanded entities
  char* script_buffer_lower_;     // Holds lowercased text
  bool letters_marks_only_;       // To distinguish scriptspan of one
                                  // letters/marks vs. any mixture of text
  bool one_script_only_;          // To distinguish scriptspan of one
                                  // script vs. any mixture of scripts
  int exit_state_;                // For tag parser kTagParseTbl_0, based
                                  // on letters_marks_only_
 public :
  // Expose for debugging
  OffsetMap map2original_;    // map from script_buffer_ to buffer
  OffsetMap map2uplow_;       // map from script_buffer_lower_ to script_buffer_
};