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88 lines
3.4 KiB
C++
88 lines
3.4 KiB
C++
/**********************************************************************
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* File: normstrngs.h
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* Description: Utilities to normalize and manipulate UTF-32 and
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* UTF-8 strings.
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* Author: Ranjith Unnikrishnan
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* Created: Thu July 4 2013
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*
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* (C) Copyright 2013, Google Inc.
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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* http://www.apache.org/licenses/LICENSE-2.0
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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**********************************************************************/
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#ifndef TESSERACT_CCUTIL_NORMSTRNGS_H_
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#define TESSERACT_CCUTIL_NORMSTRNGS_H_
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#include "genericvector.h"
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#include "strngs.h"
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typedef signed int char32;
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namespace tesseract {
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// UTF-8 to UTF-32 conversion function.
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void UTF8ToUTF32(const char* utf8_str, GenericVector<char32>* str32);
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// UTF-32 to UTF-8 convesion function.
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void UTF32ToUTF8(const GenericVector<char32>& str32, STRING* utf8_str);
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// Normalize a single char32 using NFKC + OCR-specific transformations.
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// NOTE that proper NFKC may require multiple characters as input. The
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// assumption of this function is that the input is already as fully composed
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// as it can be, but may require some compatibility normalizations or just
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// OCR evaluation related normalizations.
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void NormalizeChar32(char32 ch, bool decompose, GenericVector<char32>* str);
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// Normalize a UTF8 string. Same as above, but for UTF8-encoded strings, that
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// can contain multiple UTF32 code points.
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STRING NormalizeUTF8String(bool decompose, const char* str8);
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// Default behavior is to compose, until it is proven that decomposed benefits
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// at least one language.
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inline STRING NormalizeUTF8String(const char* str8) {
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return NormalizeUTF8String(false, str8);
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}
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// Apply just the OCR-specific normalizations and return the normalized char.
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char32 OCRNormalize(char32 ch);
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// Returns true if the OCRNormalized ch1 and ch2 are the same.
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bool IsOCREquivalent(char32 ch1, char32 ch2);
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// Returns true if the value lies in the range of valid unicodes.
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bool IsValidCodepoint(const char32 ch);
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// Returns true a code point has the White_Space Unicode property.
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bool IsWhitespace(const char32 ch);
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// Returns true if every char in the given (null-terminated) string has the
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// White_Space Unicode property.
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bool IsUTF8Whitespace(const char* text);
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// Returns the length of bytes of the prefix of 'text' that have the White_Space
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// unicode property.
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int SpanUTF8Whitespace(const char* text);
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// Returns the length of bytes of the prefix of 'text' that DO NOT have the
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// White_Space unicode property.
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int SpanUTF8NotWhitespace(const char* text);
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// Returns true if the char is interchange valid i.e. no C0 or C1 control codes
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// (other than CR LF HT FF) and no non-characters.
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bool IsInterchangeValid(const char32 ch);
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// Same as above but restricted to 7-bit ASCII.
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bool IsInterchangeValid7BitAscii(const char32 ch);
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// Convert a full-width UTF-8 string to half-width.
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char32 FullwidthToHalfwidth(const char32 ch);
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} // namespace tesseract
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#endif // TESSERACT_CCUTIL_NORMSTRNGS_H_
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