tesseract/src/training/validate_grapheme.h

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2018-04-25 16:35:26 +08:00
#ifndef TESSERACT_TRAINING_VALIDATE_GRAPHEME_H_
#define TESSERACT_TRAINING_VALIDATE_GRAPHEME_H_
#include "validator.h"
namespace tesseract {
// Subclass of Validator that validates and segments generic unicode into
// grapheme clusters, including Latin with diacritics.
class ValidateGrapheme : public Validator {
public:
ValidateGrapheme(ViramaScript script, bool report_errors)
: Validator(script, report_errors) {}
~ValidateGrapheme() {}
protected:
// Consumes the next Grapheme in codes_[codes_used_++...] and copies it to
// parts_ and output_. Returns true if a valid Grapheme was consumed,
// otherwise does not increment codes_used_.
bool ConsumeGraphemeIfValid() override;
// Returns the CharClass corresponding to the given Unicode ch.
CharClass UnicodeToCharClass(char32 ch) const override;
private:
// Helper returns true if the sequence prev_ch,ch is invalid.
bool IsBadlyFormed(char32 prev_ch, char32 ch);
// Helper returns true if the sequence prev_ch,ch is an invalid Indic vowel.
static bool IsBadlyFormedIndicVowel(char32 prev_ch, char32 ch);
// Helper returns true if the sequence prev_ch,ch is invalid Thai.
static bool IsBadlyFormedThai(char32 prev_ch, char32 ch);
};
} // namespace tesseract
#endif // TESSERACT_TRAINING_VALIDATE_GRAPHEME_H_