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// Copyright 2013 Google Inc. All Rights Reserved.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.
// Author: (Dick Sites)
#include "integral_types.h"
#include "langspan.h"
#include "offsetmap.h"
namespace CLD2 {
static const int kMaxScriptBuffer = 40960;
static const int kMaxScriptLowerBuffer = (kMaxScriptBuffer * 3) / 2;
static const int kMaxScriptBytes = kMaxScriptBuffer - 32; // Leave some room
static const int kWithinScriptTail = 32; // Stop at word space in last
// N bytes of script buffer
static inline bool IsContinuationByte(char c) {
return static_cast<signed char>(c) < -64;
// Gets lscript number for letters; always returns
// 0 (common script) for non-letters
int GetUTF8LetterScriptNum(const char* src);
// Update src pointer to point to next quadgram, +2..+5
// Looks at src[0..4]
const char* AdvanceQuad(const char* src);
class ScriptScanner {
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);
// 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_;};
// 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_
} // namespace CLD2