| /////////////////////////////////////////////////////////////////////// |
| // File: unichar.h |
| // Description: Unicode character/ligature class. |
| // Author: Ray Smith |
| // Created: Wed Jun 28 17:05:01 PDT 2006 |
| // |
| // (C) Copyright 2006, Google Inc. |
| // 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 |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| // |
| /////////////////////////////////////////////////////////////////////// |
| |
| #ifndef TESSERACT_CCUTIL_UNICHAR_H__ |
| #define TESSERACT_CCUTIL_UNICHAR_H__ |
| |
| #include <memory.h> |
| #include <string.h> |
| |
| // Maximum number of characters that can be stored in a UNICHAR. Must be |
| // at least 4. Must not exceed 31 without changing the coding of length. |
| #define UNICHAR_LEN 24 |
| |
| // A UNICHAR_ID is the unique id of a unichar. |
| typedef int UNICHAR_ID; |
| |
| // A variable to indicate an invalid or uninitialized unichar id. |
| static const int INVALID_UNICHAR_ID = -1; |
| // A special unichar that corresponds to INVALID_UNICHAR_ID. |
| static const char INVALID_UNICHAR[] = "__INVALID_UNICHAR__"; |
| |
| // The UNICHAR class holds a single classification result. This may be |
| // a single Unicode character (stored as between 1 and 4 utf8 bytes) or |
| // multple Unicode characters representing the NFKC expansion of a ligature |
| // such as fi, ffl etc. These are also stored as utf8. |
| class UNICHAR { |
| public: |
| UNICHAR() { |
| memset(chars, 0, UNICHAR_LEN); |
| } |
| |
| // Construct from a utf8 string. If len<0 then the string is null terminated. |
| // If the string is too long to fit in the UNICHAR then it takes only what |
| // will fit. |
| UNICHAR(const char* utf8_str, int len); |
| |
| // Construct from a single UCS4 character. |
| explicit UNICHAR(int unicode); |
| |
| // Default copy constructor and operator= are OK. |
| |
| // Get the first character as UCS-4. |
| int first_uni() const; |
| |
| // Get the length of the UTF8 string. |
| int utf8_len() const { |
| int len = chars[UNICHAR_LEN - 1]; |
| return len >=0 && len < UNICHAR_LEN ? len : UNICHAR_LEN; |
| } |
| |
| // Get a UTF8 string, but NOT NULL terminated. |
| const char* utf8() const { |
| return chars; |
| } |
| |
| // Get a terminated UTF8 string: Must delete[] it after use. |
| char* utf8_str() const; |
| |
| // Get the number of bytes in the first character of the given utf8 string. |
| static int utf8_step(const char* utf8_str); |
| |
| private: |
| // A UTF-8 representation of 1 or more Unicode characters. |
| // The last element (chars[UNICHAR_LEN - 1]) is a length if |
| // its value < UNICHAR_LEN, otherwise it is a genuine character. |
| char chars[UNICHAR_LEN]; |
| }; |
| |
| #endif // TESSERACT_CCUTIL_UNICHAR_H__ |