unicharset.h

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// File:        unicharset.h
// Description: Unicode character/ligature set class.
// Author:      Thomas Kielbus
//
// (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_UNICHARSET_H_
#define TESSERACT_CCUTIL_UNICHARSET_H_
 
#include "errcode.h"
#include "unicharmap.h"
 
#include <tesseract/unichar.h>
#include "helpers.h"
#include "serialis.h"
 
#include <functional> // for std::function
 
namespace tesseract {
 
// Enum holding special values of unichar_id. Every unicharset has these.
// Warning! Keep in sync with kSpecialUnicharCodes.
enum SpecialUnicharCodes {
  UNICHAR_SPACE,
  UNICHAR_JOINED,
  UNICHAR_BROKEN,
 
  SPECIAL_UNICHAR_CODES_COUNT
};
 
// Boolean flag for unichar_insert. It's a bit of a double negative to allow
// the default value to be false.
enum class OldUncleanUnichars {
  kFalse,
  kTrue,
};
 
class TESS_API CHAR_FRAGMENT {
public:
  // Minimum number of characters used for fragment representation.
  static const int kMinLen = 6;
  // Maximum number of characters used for fragment representation.
  static const int kMaxLen = 3 + UNICHAR_LEN + 2;
  // Maximum number of fragments per character.
  static const int kMaxChunks = 5;
 
  // Setters and Getters.
  inline void set_all(const char *unichar, int pos, int total, bool natural) {
    set_unichar(unichar);
    set_pos(pos);
    set_total(total);
    set_natural(natural);
  }
  inline void set_unichar(const char *uch) {
    strncpy(this->unichar, uch, sizeof(this->unichar));
    this->unichar[UNICHAR_LEN] = '\0';
  }
  inline void set_pos(int p) {
    this->pos = p;
  }
  inline void set_total(int t) {
    this->total = t;
  }
  inline const char *get_unichar() const {
    return this->unichar;
  }
  inline int get_pos() const {
    return this->pos;
  }
  inline int get_total() const {
    return this->total;
  }
 
  // Returns the string that represents a fragment
  // with the given unichar, pos and total.
  static std::string to_string(const char *unichar, int pos, int total,
                               bool natural);
  // Returns the string that represents this fragment.
  std::string to_string() const {
    return to_string(unichar, pos, total, natural);
  }
 
  // Checks whether a fragment has the same unichar,
  // position and total as the given inputs.
  inline bool equals(const char *other_unichar, int other_pos,
                     int other_total) const {
    return (strcmp(this->unichar, other_unichar) == 0 &&
            this->pos == other_pos && this->total == other_total);
  }
  inline bool equals(const CHAR_FRAGMENT *other) const {
    return this->equals(other->get_unichar(), other->get_pos(),
                        other->get_total());
  }
 
  // Checks whether a given fragment is a continuation of this fragment.
  // Assumes that the given fragment pointer is not nullptr.
  inline bool is_continuation_of(const CHAR_FRAGMENT *fragment) const {
    return (strcmp(this->unichar, fragment->get_unichar()) == 0 &&
            this->total == fragment->get_total() &&
            this->pos == fragment->get_pos() + 1);
  }
 
  // Returns true if this fragment is a beginning fragment.
  inline bool is_beginning() const {
    return this->pos == 0;
  }
 
  // Returns true if this fragment is an ending fragment.
  inline bool is_ending() const {
    return this->pos == this->total - 1;
  }
 
  // Returns true if the fragment was a separate component to begin with,
  // ie did not need chopping to be isolated, but may have been separated
  // out from a multi-outline blob.
  inline bool is_natural() const {
    return natural;
  }
  void set_natural(bool value) {
    natural = value;
  }
 
  // Parses the string to see whether it represents a character fragment
  // (rather than a regular character). If so, allocates memory for a new
  // CHAR_FRAGMENT instance and fills it in with the corresponding fragment
  // information. Fragments are of the form:
  // |m|1|2, meaning chunk 1 of 2 of character m, or
  // |:|1n2, meaning chunk 1 of 2 of character :, and no chopping was needed
  // to divide the parts, as they were already separate connected components.
  //
  // If parsing succeeded returns the pointer to the allocated CHAR_FRAGMENT
  // instance, otherwise (if the string does not represent a fragment or it
  // looks like it does, but parsing it as a fragment fails) returns nullptr.
  //
  // Note: The caller is responsible for deallocating memory
  // associated with the returned pointer.
  static CHAR_FRAGMENT *parse_from_string(const char *str);
 
private:
  char unichar[UNICHAR_LEN + 1];
  // True if the fragment was a separate component to begin with,
  // ie did not need chopping to be isolated, but may have been separated
  // out from a multi-outline blob.
  bool natural;
  int16_t pos;   // fragment position in the character
  int16_t total; // total number of fragments in the character
};
 
// The UNICHARSET class is an utility class for Tesseract that holds the
// set of characters that are used by the engine. Each character is identified
// by a unique number, from 0 to (size - 1).
class TESS_API UNICHARSET {
public:
  // Custom list of characters and their ligature forms (UTF8)
  // These map to unicode values in the private use area (PUC) and are supported
  // by only few font families (eg. Wyld, Adobe Caslon Pro).
  static const char *kCustomLigatures[][2];
 
  // List of strings for the SpecialUnicharCodes. Keep in sync with the enum.
  static const char *kSpecialUnicharCodes[SPECIAL_UNICHAR_CODES_COUNT];
 
  // ICU 2.0 UCharDirection enum (from icu/include/unicode/uchar.h)
  enum Direction {
    U_LEFT_TO_RIGHT = 0,
    U_RIGHT_TO_LEFT = 1,
    U_EUROPEAN_NUMBER = 2,
    U_EUROPEAN_NUMBER_SEPARATOR = 3,
    U_EUROPEAN_NUMBER_TERMINATOR = 4,
    U_ARABIC_NUMBER = 5,
    U_COMMON_NUMBER_SEPARATOR = 6,
    U_BLOCK_SEPARATOR = 7,
    U_SEGMENT_SEPARATOR = 8,
    U_WHITE_SPACE_NEUTRAL = 9,
    U_OTHER_NEUTRAL = 10,
    U_LEFT_TO_RIGHT_EMBEDDING = 11,
    U_LEFT_TO_RIGHT_OVERRIDE = 12,
    U_RIGHT_TO_LEFT_ARABIC = 13,
    U_RIGHT_TO_LEFT_EMBEDDING = 14,
    U_RIGHT_TO_LEFT_OVERRIDE = 15,
    U_POP_DIRECTIONAL_FORMAT = 16,
    U_DIR_NON_SPACING_MARK = 17,
    U_BOUNDARY_NEUTRAL = 18,
    U_FIRST_STRONG_ISOLATE = 19,
    U_LEFT_TO_RIGHT_ISOLATE = 20,
    U_RIGHT_TO_LEFT_ISOLATE = 21,
    U_POP_DIRECTIONAL_ISOLATE = 22,
#ifndef U_HIDE_DEPRECATED_API
    U_CHAR_DIRECTION_COUNT
#endif // U_HIDE_DEPRECATED_API
  };
 
  // Create an empty UNICHARSET
  UNICHARSET();
 
  ~UNICHARSET();
 
  // Return the UNICHAR_ID of a given unichar representation within the
  // UNICHARSET.
  UNICHAR_ID unichar_to_id(const char *const unichar_repr) const;
 
  // Return the UNICHAR_ID of a given unichar representation within the
  // UNICHARSET. Only the first length characters from unichar_repr are used.
  UNICHAR_ID unichar_to_id(const char *const unichar_repr, int length) const;
 
  // Return the minimum number of bytes that matches a legal UNICHAR_ID,
  // while leaving the rest of the string encodable. Returns 0 if the
  // beginning of the string is not encodable.
  // WARNING: this function now encodes the whole string for precision.
  // Use encode_string in preference to repeatedly calling step.
  int step(const char *str) const;
 
  // Returns true if the given UTF-8 string is encodable with this UNICHARSET.
  // If not encodable, write the first byte offset which cannot be converted
  // into the second (return) argument.
  bool encodable_string(const char *str, unsigned *first_bad_position) const;
 
  // Encodes the given UTF-8 string with this UNICHARSET.
  // Any part of the string that cannot be encoded (because the utf8 can't
  // be broken up into pieces that are in the unicharset) then:
  // if give_up_on_failure, stops and returns a partial encoding,
  // else continues and inserts an INVALID_UNICHAR_ID in the returned encoding.
  // Returns true if the encoding succeeds completely, false if there is at
  // least one failure.
  // If lengths is not nullptr, then it is filled with the corresponding
  // byte length of each encoded UNICHAR_ID.
  // If encoded_length is not nullptr then on return it contains the length of
  // str that was encoded. (if give_up_on_failure the location of the first
  // failure, otherwise strlen(str).)
  // WARNING: Caller must guarantee that str has already been cleaned of codes
  // that do not belong in the unicharset, or encoding may fail.
  // Use CleanupString to perform the cleaning.
  bool encode_string(const char *str, bool give_up_on_failure,
                     std::vector<UNICHAR_ID> *encoding,
                     std::vector<char> *lengths,
                     unsigned *encoded_length) const;
 
  // Return the unichar representation corresponding to the given UNICHAR_ID
  // within the UNICHARSET.
  const char *id_to_unichar(UNICHAR_ID id) const;
 
  // Return the UTF8 representation corresponding to the given UNICHAR_ID after
  // resolving any private encodings internal to Tesseract. This method is
  // preferable to id_to_unichar for outputting text that will be visible to
  // external applications.
  const char *id_to_unichar_ext(UNICHAR_ID id) const;
 
  // Return a string that reformats the utf8 str into the str followed
  // by its hex unicodes.
  static std::string debug_utf8_str(const char *str);
 
  // Removes/replaces content that belongs in rendered text, but not in the
  // unicharset.
  static std::string CleanupString(const char *utf8_str) {
    return CleanupString(utf8_str, strlen(utf8_str));
  }
  static std::string CleanupString(const char *utf8_str, size_t length);
 
  // Return a string containing debug information on the unichar, including
  // the id_to_unichar, its hex unicodes and the properties.
  std::string debug_str(UNICHAR_ID id) const;
  std::string debug_str(const char *unichar_repr) const {
    return debug_str(unichar_to_id(unichar_repr));
  }
 
  // Adds a unichar representation to the set. If old_style is true, then
  // TATWEEL characters are kept and n-grams are allowed. Otherwise TATWEEL
  // characters are ignored/skipped as if they don't exist and n-grams that
  // can already be encoded are not added.
  void unichar_insert(const char *const unichar_repr,
                      OldUncleanUnichars old_style);
  void unichar_insert(const char *const unichar_repr) {
    unichar_insert(unichar_repr, OldUncleanUnichars::kFalse);
  }
  // Adds a unichar representation to the set. Avoids setting old_style to true,
  // unless it is necessary to make the new unichar get added.
  void unichar_insert_backwards_compatible(const char *const unichar_repr) {
    std::string cleaned = CleanupString(unichar_repr);
    if (cleaned != unichar_repr) {
      unichar_insert(unichar_repr, OldUncleanUnichars::kTrue);
    } else {
      auto old_size = size();
      unichar_insert(unichar_repr, OldUncleanUnichars::kFalse);
      if (size() == old_size) {
        unichar_insert(unichar_repr, OldUncleanUnichars::kTrue);
      }
    }
  }
 
  // Return true if the given unichar id exists within the set.
  // Relies on the fact that unichar ids are contiguous in the unicharset.
  bool contains_unichar_id(UNICHAR_ID unichar_id) const {
    return static_cast<size_t>(unichar_id) < unichars.size();
  }
 
  // Return true if the given unichar representation exists within the set.
  bool contains_unichar(const char *const unichar_repr) const;
  bool contains_unichar(const char *const unichar_repr, int length) const;
 
  // Return true if the given unichar representation corresponds to the given
  // UNICHAR_ID within the set.
  bool eq(UNICHAR_ID unichar_id, const char *const unichar_repr) const;
 
  // Delete CHAR_FRAGMENTs stored in properties of unichars array.
  void delete_pointers_in_unichars() {
    for (auto &unichar : unichars) {
      delete unichar.properties.fragment;
      unichar.properties.fragment = nullptr;
    }
  }
 
  // Clear the UNICHARSET (all the previous data is lost).
  void clear() {
    if (script_table != nullptr) {
      for (int i = 0; i < script_table_size_used; ++i) {
        delete[] script_table[i];
      }
      delete[] script_table;
      script_table = nullptr;
      script_table_size_used = 0;
    }
    script_table_size_reserved = 0;
    delete_pointers_in_unichars();
    unichars.clear();
    ids.clear();
    top_bottom_set_ = false;
    script_has_upper_lower_ = false;
    script_has_xheight_ = false;
    old_style_included_ = false;
    null_sid_ = 0;
    common_sid_ = 0;
    latin_sid_ = 0;
    cyrillic_sid_ = 0;
    greek_sid_ = 0;
    han_sid_ = 0;
    hiragana_sid_ = 0;
    katakana_sid_ = 0;
    thai_sid_ = 0;
    hangul_sid_ = 0;
    default_sid_ = 0;
  }
 
  // Return the size of the set (the number of different UNICHAR it holds).
  size_t size() const {
    return unichars.size();
  }
 
  // Opens the file indicated by filename and saves unicharset to that file.
  // Returns true if the operation is successful.
  bool save_to_file(const char *const filename) const {
    FILE *file = fopen(filename, "w+b");
    if (file == nullptr) {
      return false;
    }
    bool result = save_to_file(file);
    fclose(file);
    return result;
  }
 
  // Saves the content of the UNICHARSET to the given file.
  // Returns true if the operation is successful.
  bool save_to_file(FILE *file) const {
    std::string str;
    return save_to_string(str) &&
           tesseract::Serialize(file, &str[0], str.length());
  }
 
  bool save_to_file(tesseract::TFile *file) const {
    std::string str;
    return save_to_string(str) && file->Serialize(&str[0], str.length());
  }
 
  // Saves the content of the UNICHARSET to the given string.
  // Returns true if the operation is successful.
  bool save_to_string(std::string &str) const;
 
  // Opens the file indicated by filename and loads the UNICHARSET
  // from the given file. The previous data is lost.
  // Returns true if the operation is successful.
  bool load_from_file(const char *const filename, bool skip_fragments) {
    FILE *file = fopen(filename, "rb");
    if (file == nullptr) {
      return false;
    }
    bool result = load_from_file(file, skip_fragments);
    fclose(file);
    return result;
  }
  // returns true if the operation is successful.
  bool load_from_file(const char *const filename) {
    return load_from_file(filename, false);
  }
 
  // Loads the UNICHARSET from the given file. The previous data is lost.
  // Returns true if the operation is successful.
  bool load_from_file(FILE *file, bool skip_fragments);
  bool load_from_file(FILE *file) {
    return load_from_file(file, false);
  }
  bool load_from_file(tesseract::TFile *file, bool skip_fragments);
 
  // Sets up internal data after loading the file, based on the char
  // properties. Called from load_from_file, but also needs to be run
  // during set_unicharset_properties.
  void post_load_setup();
 
  // Returns true if right_to_left scripts are significant in the unicharset,
  // but without being so sensitive that "universal" unicharsets containing
  // characters from many scripts, like orientation and script detection,
  // look like they are right_to_left.
  bool major_right_to_left() const;
 
  // Set a whitelist and/or blacklist of characters to recognize.
  // An empty or nullptr whitelist enables everything (minus any blacklist).
  // An empty or nullptr blacklist disables nothing.
  // An empty or nullptr unblacklist has no effect.
  // The blacklist overrides the whitelist.
  // The unblacklist overrides the blacklist.
  // Each list is a string of utf8 character strings. Boundaries between
  // unicharset units are worked out automatically, and characters not in
  // the unicharset are silently ignored.
  void set_black_and_whitelist(const char *blacklist, const char *whitelist,
                               const char *unblacklist);
 
  // Set the isalpha property of the given unichar to the given value.
  void set_isalpha(UNICHAR_ID unichar_id, bool value) {
    unichars[unichar_id].properties.isalpha = value;
  }
 
  // Set the islower property of the given unichar to the given value.
  void set_islower(UNICHAR_ID unichar_id, bool value) {
    unichars[unichar_id].properties.islower = value;
  }
 
  // Set the isupper property of the given unichar to the given value.
  void set_isupper(UNICHAR_ID unichar_id, bool value) {
    unichars[unichar_id].properties.isupper = value;
  }
 
  // Set the isdigit property of the given unichar to the given value.
  void set_isdigit(UNICHAR_ID unichar_id, bool value) {
    unichars[unichar_id].properties.isdigit = value;
  }
 
  // Set the ispunctuation property of the given unichar to the given value.
  void set_ispunctuation(UNICHAR_ID unichar_id, bool value) {
    unichars[unichar_id].properties.ispunctuation = value;
  }
 
  // Set the isngram property of the given unichar to the given value.
  void set_isngram(UNICHAR_ID unichar_id, bool value) {
    unichars[unichar_id].properties.isngram = value;
  }
 
  // Set the script name of the given unichar to the given value.
  // Value is copied and thus can be a temporary;
  void set_script(UNICHAR_ID unichar_id, const char *value) {
    unichars[unichar_id].properties.script_id = add_script(value);
  }
 
  // Set other_case unichar id in the properties for the given unichar id.
  void set_other_case(UNICHAR_ID unichar_id, UNICHAR_ID other_case) {
    unichars[unichar_id].properties.other_case = other_case;
  }
 
  // Set the direction property of the given unichar to the given value.
  void set_direction(UNICHAR_ID unichar_id, UNICHARSET::Direction value) {
    unichars[unichar_id].properties.direction = value;
  }
 
  // Set mirror unichar id in the properties for the given unichar id.
  void set_mirror(UNICHAR_ID unichar_id, UNICHAR_ID mirror) {
    unichars[unichar_id].properties.mirror = mirror;
  }
 
  // Record normalized version of unichar with the given unichar_id.
  void set_normed(UNICHAR_ID unichar_id, const char *normed) {
    unichars[unichar_id].properties.normed = normed;
    unichars[unichar_id].properties.normed_ids.clear();
  }
  // Sets the normed_ids vector from the normed string. normed_ids is not
  // stored in the file, and needs to be set when the UNICHARSET is loaded.
  void set_normed_ids(UNICHAR_ID unichar_id);
 
  // Return the isalpha property of the given unichar.
  bool get_isalpha(UNICHAR_ID unichar_id) const {
    if (INVALID_UNICHAR_ID == unichar_id) {
      return false;
    }
    ASSERT_HOST(contains_unichar_id(unichar_id));
    return unichars[unichar_id].properties.isalpha;
  }
 
  // Return the islower property of the given unichar.
  bool get_islower(UNICHAR_ID unichar_id) const {
    if (INVALID_UNICHAR_ID == unichar_id) {
      return false;
    }
    ASSERT_HOST(contains_unichar_id(unichar_id));
    return unichars[unichar_id].properties.islower;
  }
 
  // Return the isupper property of the given unichar.
  bool get_isupper(UNICHAR_ID unichar_id) const {
    if (INVALID_UNICHAR_ID == unichar_id) {
      return false;
    }
    ASSERT_HOST(contains_unichar_id(unichar_id));
    return unichars[unichar_id].properties.isupper;
  }
 
  // Return the isdigit property of the given unichar.
  bool get_isdigit(UNICHAR_ID unichar_id) const {
    if (INVALID_UNICHAR_ID == unichar_id) {
      return false;
    }
    ASSERT_HOST(contains_unichar_id(unichar_id));
    return unichars[unichar_id].properties.isdigit;
  }
 
  // Return the ispunctuation property of the given unichar.
  bool get_ispunctuation(UNICHAR_ID unichar_id) const {
    if (INVALID_UNICHAR_ID == unichar_id) {
      return false;
    }
    ASSERT_HOST(contains_unichar_id(unichar_id));
    return unichars[unichar_id].properties.ispunctuation;
  }
 
  // Return the isngram property of the given unichar.
  bool get_isngram(UNICHAR_ID unichar_id) const {
    if (INVALID_UNICHAR_ID == unichar_id) {
      return false;
    }
    ASSERT_HOST(contains_unichar_id(unichar_id));
    return unichars[unichar_id].properties.isngram;
  }
 
  // Returns whether the unichar id represents a unicode value in the private
  // use area.
  bool get_isprivate(UNICHAR_ID unichar_id) const;
 
  // Returns true if the ids have useful min/max top/bottom values.
  bool top_bottom_useful() const {
    return top_bottom_set_;
  }
  // Sets all ranges to empty, so they can be expanded to set the values.
  void set_ranges_empty();
  // Sets all the properties for this unicharset given a src_unicharset with
  // everything set. The unicharsets don't have to be the same, and graphemes
  // are correctly accounted for.
  void SetPropertiesFromOther(const UNICHARSET &src) {
    PartialSetPropertiesFromOther(0, src);
  }
  // Sets properties from Other, starting only at the given index.
  void PartialSetPropertiesFromOther(int start_index, const UNICHARSET &src);
  // Expands the tops and bottoms and widths for this unicharset given a
  // src_unicharset with ranges in it. The unicharsets don't have to be the
  // same, and graphemes are correctly accounted for.
  void ExpandRangesFromOther(const UNICHARSET &src);
  // Makes this a copy of src. Clears this completely first, so the automattic
  // ids will not be present in this if not in src.
  void CopyFrom(const UNICHARSET &src);
  // For each id in src, if it does not occur in this, add it, as in
  // SetPropertiesFromOther, otherwise expand the ranges, as in
  // ExpandRangesFromOther.
  void AppendOtherUnicharset(const UNICHARSET &src);
  // Returns true if the acceptable ranges of the tops of the characters do
  // not overlap, making their x-height calculations distinct.
  bool SizesDistinct(UNICHAR_ID id1, UNICHAR_ID id2) const;
  // Returns the min and max bottom and top of the given unichar in
  // baseline-normalized coordinates, ie, where the baseline is
  // kBlnBaselineOffset and the meanline is kBlnBaselineOffset + kBlnXHeight
  // (See normalis.h for the definitions).
  void get_top_bottom(UNICHAR_ID unichar_id, int *min_bottom, int *max_bottom,
                      int *min_top, int *max_top) const {
    if (INVALID_UNICHAR_ID == unichar_id) {
      *min_bottom = *min_top = 0;
      *max_bottom = *max_top = 256; // kBlnCellHeight
      return;
    }
    ASSERT_HOST(contains_unichar_id(unichar_id));
    *min_bottom = unichars[unichar_id].properties.min_bottom;
    *max_bottom = unichars[unichar_id].properties.max_bottom;
    *min_top = unichars[unichar_id].properties.min_top;
    *max_top = unichars[unichar_id].properties.max_top;
  }
  void set_top_bottom(UNICHAR_ID unichar_id, int min_bottom, int max_bottom,
                      int min_top, int max_top) {
    unichars[unichar_id].properties.min_bottom =
        ClipToRange<int>(min_bottom, 0, UINT8_MAX);
    unichars[unichar_id].properties.max_bottom =
        ClipToRange<int>(max_bottom, 0, UINT8_MAX);
    unichars[unichar_id].properties.min_top =
        ClipToRange<int>(min_top, 0, UINT8_MAX);
    unichars[unichar_id].properties.max_top =
        ClipToRange<int>(max_top, 0, UINT8_MAX);
  }
  // Returns the width stats (as mean, sd) of the given unichar relative to the
  // median advance of all characters in the character set.
  void get_width_stats(UNICHAR_ID unichar_id, float *width,
                       float *width_sd) const {
    if (INVALID_UNICHAR_ID == unichar_id) {
      *width = 0.0f;
      *width_sd = 0.0f;
      return;
    }
    ASSERT_HOST(contains_unichar_id(unichar_id));
    *width = unichars[unichar_id].properties.width;
    *width_sd = unichars[unichar_id].properties.width_sd;
  }
  void set_width_stats(UNICHAR_ID unichar_id, float width, float width_sd) {
    unichars[unichar_id].properties.width = width;
    unichars[unichar_id].properties.width_sd = width_sd;
  }
  // Returns the stats of the x-bearing (as mean, sd) of the given unichar
  // relative to the median advance of all characters in the character set.
  void get_bearing_stats(UNICHAR_ID unichar_id, float *bearing,
                         float *bearing_sd) const {
    if (INVALID_UNICHAR_ID == unichar_id) {
      *bearing = *bearing_sd = 0.0f;
      return;
    }
    ASSERT_HOST(contains_unichar_id(unichar_id));
    *bearing = unichars[unichar_id].properties.bearing;
    *bearing_sd = unichars[unichar_id].properties.bearing_sd;
  }
  void set_bearing_stats(UNICHAR_ID unichar_id, float bearing,
                         float bearing_sd) {
    unichars[unichar_id].properties.bearing = bearing;
    unichars[unichar_id].properties.bearing_sd = bearing_sd;
  }
  // Returns the stats of the x-advance of the given unichar (as mean, sd)
  // relative to the median advance of all characters in the character set.
  void get_advance_stats(UNICHAR_ID unichar_id, float *advance,
                         float *advance_sd) const {
    if (INVALID_UNICHAR_ID == unichar_id) {
      *advance = *advance_sd = 0;
      return;
    }
    ASSERT_HOST(contains_unichar_id(unichar_id));
    *advance = unichars[unichar_id].properties.advance;
    *advance_sd = unichars[unichar_id].properties.advance_sd;
  }
  void set_advance_stats(UNICHAR_ID unichar_id, float advance,
                         float advance_sd) {
    unichars[unichar_id].properties.advance = advance;
    unichars[unichar_id].properties.advance_sd = advance_sd;
  }
  // Returns true if the font metrics properties are empty.
  bool PropertiesIncomplete(UNICHAR_ID unichar_id) const {
    return unichars[unichar_id].properties.AnyRangeEmpty();
  }
 
  // Returns true if the script of the given id is space delimited.
  // Returns false for Han and Thai scripts.
  bool IsSpaceDelimited(UNICHAR_ID unichar_id) const {
    if (INVALID_UNICHAR_ID == unichar_id) {
      return true;
    }
    int script_id = get_script(unichar_id);
    return script_id != han_sid_ && script_id != thai_sid_ &&
           script_id != hangul_sid_ && script_id != hiragana_sid_ &&
           script_id != katakana_sid_;
  }
 
  // Return the script name of the given unichar.
  // The returned pointer will always be the same for the same script, it's
  // managed by unicharset and thus MUST NOT be deleted
  int get_script(UNICHAR_ID unichar_id) const {
    if (INVALID_UNICHAR_ID == unichar_id) {
      return null_sid_;
    }
    ASSERT_HOST(contains_unichar_id(unichar_id));
    return unichars[unichar_id].properties.script_id;
  }
 
  // Return the character properties, eg. alpha/upper/lower/digit/punct,
  // as a bit field of unsigned int.
  unsigned int get_properties(UNICHAR_ID unichar_id) const;
 
  // Return the character property as a single char.  If a character has
  // multiple attributes, the main property is defined by the following order:
  //   upper_case : 'A'
  //   lower_case : 'a'
  //   alpha      : 'x'
  //   digit      : '0'
  //   punctuation: 'p'
  char get_chartype(UNICHAR_ID unichar_id) const;
 
  // Get other_case unichar id in the properties for the given unichar id.
  UNICHAR_ID get_other_case(UNICHAR_ID unichar_id) const {
    if (INVALID_UNICHAR_ID == unichar_id) {
      return INVALID_UNICHAR_ID;
    }
    ASSERT_HOST(contains_unichar_id(unichar_id));
    return unichars[unichar_id].properties.other_case;
  }
 
  // Returns the direction property of the given unichar.
  Direction get_direction(UNICHAR_ID unichar_id) const {
    if (INVALID_UNICHAR_ID == unichar_id) {
      return UNICHARSET::U_OTHER_NEUTRAL;
    }
    ASSERT_HOST(contains_unichar_id(unichar_id));
    return unichars[unichar_id].properties.direction;
  }
 
  // Get mirror unichar id in the properties for the given unichar id.
  UNICHAR_ID get_mirror(UNICHAR_ID unichar_id) const {
    if (INVALID_UNICHAR_ID == unichar_id) {
      return INVALID_UNICHAR_ID;
    }
    ASSERT_HOST(contains_unichar_id(unichar_id));
    return unichars[unichar_id].properties.mirror;
  }
 
  // Returns UNICHAR_ID of the corresponding lower-case unichar.
  UNICHAR_ID to_lower(UNICHAR_ID unichar_id) const {
    if (INVALID_UNICHAR_ID == unichar_id) {
      return INVALID_UNICHAR_ID;
    }
    ASSERT_HOST(contains_unichar_id(unichar_id));
    if (unichars[unichar_id].properties.islower) {
      return unichar_id;
    }
    return unichars[unichar_id].properties.other_case;
  }
 
  // Returns UNICHAR_ID of the corresponding upper-case unichar.
  UNICHAR_ID to_upper(UNICHAR_ID unichar_id) const {
    if (INVALID_UNICHAR_ID == unichar_id) {
      return INVALID_UNICHAR_ID;
    }
    ASSERT_HOST(contains_unichar_id(unichar_id));
    if (unichars[unichar_id].properties.isupper) {
      return unichar_id;
    }
    return unichars[unichar_id].properties.other_case;
  }
 
  // Returns true if this UNICHARSET has the special codes in
  // SpecialUnicharCodes available. If false then there are normal unichars
  // at these codes and they should not be used.
  bool has_special_codes() const {
    return get_fragment(UNICHAR_BROKEN) != nullptr &&
           strcmp(id_to_unichar(UNICHAR_BROKEN),
                  kSpecialUnicharCodes[UNICHAR_BROKEN]) == 0;
  }
 
  // Returns true if there are any repeated unicodes in the normalized
  // text of any unichar-id in the unicharset.
  bool AnyRepeatedUnicodes() const;
 
  // Return a pointer to the CHAR_FRAGMENT class if the given
  // unichar id represents a character fragment.
  const CHAR_FRAGMENT *get_fragment(UNICHAR_ID unichar_id) const {
    if (INVALID_UNICHAR_ID == unichar_id) {
      return nullptr;
    }
    ASSERT_HOST(contains_unichar_id(unichar_id));
    return unichars[unichar_id].properties.fragment;
  }
 
  // Return the isalpha property of the given unichar representation.
  bool get_isalpha(const char *const unichar_repr) const {
    return get_isalpha(unichar_to_id(unichar_repr));
  }
 
  // Return the islower property of the given unichar representation.
  bool get_islower(const char *const unichar_repr) const {
    return get_islower(unichar_to_id(unichar_repr));
  }
 
  // Return the isupper property of the given unichar representation.
  bool get_isupper(const char *const unichar_repr) const {
    return get_isupper(unichar_to_id(unichar_repr));
  }
 
  // Return the isdigit property of the given unichar representation.
  bool get_isdigit(const char *const unichar_repr) const {
    return get_isdigit(unichar_to_id(unichar_repr));
  }
 
  // Return the ispunctuation property of the given unichar representation.
  bool get_ispunctuation(const char *const unichar_repr) const {
    return get_ispunctuation(unichar_to_id(unichar_repr));
  }
 
  // Return the character properties, eg. alpha/upper/lower/digit/punct,
  // of the given unichar representation
  unsigned int get_properties(const char *const unichar_repr) const {
    return get_properties(unichar_to_id(unichar_repr));
  }
 
  char get_chartype(const char *const unichar_repr) const {
    return get_chartype(unichar_to_id(unichar_repr));
  }
 
  // Return the script name of the given unichar representation.
  // The returned pointer will always be the same for the same script, it's
  // managed by unicharset and thus MUST NOT be deleted
  int get_script(const char *const unichar_repr) const {
    return get_script(unichar_to_id(unichar_repr));
  }
 
  // Return a pointer to the CHAR_FRAGMENT class struct if the given
  // unichar representation represents a character fragment.
  const CHAR_FRAGMENT *get_fragment(const char *const unichar_repr) const {
    if (unichar_repr == nullptr || unichar_repr[0] == '\0' ||
        !ids.contains(unichar_repr, false)) {
      return nullptr;
    }
    return get_fragment(unichar_to_id(unichar_repr));
  }
 
  // Return the isalpha property of the given unichar representation.
  // Only the first length characters from unichar_repr are used.
  bool get_isalpha(const char *const unichar_repr, int length) const {
    return get_isalpha(unichar_to_id(unichar_repr, length));
  }
 
  // Return the islower property of the given unichar representation.
  // Only the first length characters from unichar_repr are used.
  bool get_islower(const char *const unichar_repr, int length) const {
    return get_islower(unichar_to_id(unichar_repr, length));
  }
 
  // Return the isupper property of the given unichar representation.
  // Only the first length characters from unichar_repr are used.
  bool get_isupper(const char *const unichar_repr, int length) const {
    return get_isupper(unichar_to_id(unichar_repr, length));
  }
 
  // Return the isdigit property of the given unichar representation.
  // Only the first length characters from unichar_repr are used.
  bool get_isdigit(const char *const unichar_repr, int length) const {
    return get_isdigit(unichar_to_id(unichar_repr, length));
  }
 
  // Return the ispunctuation property of the given unichar representation.
  // Only the first length characters from unichar_repr are used.
  bool get_ispunctuation(const char *const unichar_repr, int length) const {
    return get_ispunctuation(unichar_to_id(unichar_repr, length));
  }
 
  // Returns normalized version of unichar with the given unichar_id.
  const char *get_normed_unichar(UNICHAR_ID unichar_id) const {
    if (unichar_id == UNICHAR_SPACE) {
      return " ";
    }
    return unichars[unichar_id].properties.normed.c_str();
  }
  // Returns a vector of UNICHAR_IDs that represent the ids of the normalized
  // version of the given id. There may be more than one UNICHAR_ID in the
  // vector if unichar_id represents a ligature.
  const std::vector<UNICHAR_ID> &normed_ids(UNICHAR_ID unichar_id) const {
    return unichars[unichar_id].properties.normed_ids;
  }
 
  // Return the script name of the given unichar representation.
  // Only the first length characters from unichar_repr are used.
  // The returned pointer will always be the same for the same script, it's
  // managed by unicharset and thus MUST NOT be deleted
  int get_script(const char *const unichar_repr, int length) const {
    return get_script(unichar_to_id(unichar_repr, length));
  }
 
  // Return the (current) number of scripts in the script table
  int get_script_table_size() const {
    return script_table_size_used;
  }
 
  // Return the script string from its id
  const char *get_script_from_script_id(int id) const {
    if (id >= script_table_size_used || id < 0) {
      return null_script;
    }
    return script_table[id];
  }
 
  // Returns the id from the name of the script, or 0 if script is not found.
  // Note that this is an expensive operation since it involves iteratively
  // comparing strings in the script table.  To avoid dependency on STL, we
  // won't use a hash.  Instead, the calling function can use this to lookup
  // and save the ID for relevant scripts for fast comparisons later.
  int get_script_id_from_name(const char *script_name) const;
 
  // Return true if the given script is the null script
  bool is_null_script(const char *script) const {
    return script == null_script;
  }
 
  // Uniquify the given script. For two scripts a and b, if strcmp(a, b) == 0,
  // then the returned pointer will be the same.
  // The script parameter is copied and thus can be a temporary.
  int add_script(const char *script);
 
  // Return the enabled property of the given unichar.
  bool get_enabled(UNICHAR_ID unichar_id) const {
    ASSERT_HOST(contains_unichar_id(unichar_id));
    return unichars[unichar_id].properties.enabled;
  }
 
  int null_sid() const {
    return null_sid_;
  }
  int common_sid() const {
    return common_sid_;
  }
  int latin_sid() const {
    return latin_sid_;
  }
  int cyrillic_sid() const {
    return cyrillic_sid_;
  }
  int greek_sid() const {
    return greek_sid_;
  }
  int han_sid() const {
    return han_sid_;
  }
  int hiragana_sid() const {
    return hiragana_sid_;
  }
  int katakana_sid() const {
    return katakana_sid_;
  }
  int thai_sid() const {
    return thai_sid_;
  }
  int hangul_sid() const {
    return hangul_sid_;
  }
  int default_sid() const {
    return default_sid_;
  }
 
  // Returns true if the unicharset has the concept of upper/lower case.
  bool script_has_upper_lower() const {
    return script_has_upper_lower_;
  }
  // Returns true if the unicharset has the concept of x-height.
  // script_has_xheight can be true even if script_has_upper_lower is not,
  // when the script has a sufficiently predominant top line with ascenders,
  // such as Devanagari and Thai.
  bool script_has_xheight() const {
    return script_has_xheight_;
  }
 
private:
  struct TESS_API UNICHAR_PROPERTIES {
    UNICHAR_PROPERTIES();
    // Initializes all properties to sensible default values.
    void Init();
    // Sets all ranges wide open. Initialization default in case there are
    // no useful values available.
    void SetRangesOpen();
    // Sets all ranges to empty. Used before expanding with font-based data.
    void SetRangesEmpty();
    // Returns true if any of the top/bottom/width/bearing/advance ranges/stats
    // is empty.
    bool AnyRangeEmpty() const;
    // Expands the ranges with the ranges from the src properties.
    void ExpandRangesFrom(const UNICHAR_PROPERTIES &src);
    // Copies the properties from src into this.
    void CopyFrom(const UNICHAR_PROPERTIES &src);
 
    bool isalpha;
    bool islower;
    bool isupper;
    bool isdigit;
    bool ispunctuation;
    bool isngram;
    bool enabled;
    // Possible limits of the top and bottom of the bounding box in
    // baseline-normalized coordinates, ie, where the baseline is
    // kBlnBaselineOffset and the meanline is kBlnBaselineOffset + kBlnXHeight
    // (See normalis.h for the definitions).
    uint8_t min_bottom;
    uint8_t max_bottom;
    uint8_t min_top;
    uint8_t max_top;
    // Statistics of the widths of bounding box, relative to the median advance.
    float width;
    float width_sd;
    // Stats of the x-bearing and advance, also relative to the median advance.
    float bearing;
    float bearing_sd;
    float advance;
    float advance_sd;
    int script_id;
    UNICHAR_ID other_case; // id of the corresponding upper/lower case unichar
    Direction direction;   // direction of this unichar
    // Mirror property is useful for reverse DAWG lookup for words in
    // right-to-left languages (e.g. "(word)" would be in
    // '[open paren]' 'w' 'o' 'r' 'd' '[close paren]' in a UTF8 string.
    // However, what we want in our DAWG is
    // '[open paren]', 'd', 'r', 'o', 'w', '[close paren]' not
    // '[close paren]', 'd', 'r', 'o', 'w', '[open paren]'.
    UNICHAR_ID mirror;
    // A string of unichar_ids that represent the corresponding normed string.
    // For awkward characters like em-dash, this gives hyphen.
    // For ligatures, this gives the string of normal unichars.
    std::vector<UNICHAR_ID> normed_ids;
    std::string normed; // normalized version of this unichar
    // Contains meta information about the fragment if a unichar represents
    // a fragment of a character, otherwise should be set to nullptr.
    // It is assumed that character fragments are added to the unicharset
    // after the corresponding 'base' characters.
    CHAR_FRAGMENT *fragment;
  };
 
  struct UNICHAR_SLOT {
    char representation[UNICHAR_LEN + 1];
    UNICHAR_PROPERTIES properties;
  };
 
  // Internal recursive version of encode_string above.
  // str is the start of the whole string.
  // str_index is the current position in str.
  // str_length is the length of str.
  // encoding is a working encoding of str.
  // lengths is a working set of lengths of each element of encoding.
  // best_total_length is the longest length of str that has been successfully
  // encoded so far.
  // On return:
  // best_encoding contains the encoding that used the longest part of str.
  // best_lengths (may be null) contains the lengths of best_encoding.
  void encode_string(const char *str, int str_index, int str_length,
                     std::vector<UNICHAR_ID> *encoding,
                     std::vector<char> *lengths, unsigned *best_total_length,
                     std::vector<UNICHAR_ID> *best_encoding,
                     std::vector<char> *best_lengths) const;
 
  // Gets the properties for a grapheme string, combining properties for
  // multiple characters in a meaningful way where possible.
  // Returns false if no valid match was found in the unicharset.
  // NOTE that script_id, mirror, and other_case refer to this unicharset on
  // return and will need redirecting if the target unicharset is different.
  bool GetStrProperties(const char *utf8_str, UNICHAR_PROPERTIES *props) const;
 
  // Load ourselves from a "file" where our only interface to the file is
  // an implementation of fgets().  This is the parsing primitive accessed by
  // the public routines load_from_file().
  bool load_via_fgets(const std::function<char *(char *, int)> &fgets_cb,
                      bool skip_fragments);
 
  // List of mappings to make when ingesting strings from the outside.
  // The substitutions clean up text that should exists for rendering of
  // synthetic data, but not in the recognition set.
  static const char *kCleanupMaps[][2];
  static const char *null_script;
 
  std::vector<UNICHAR_SLOT> unichars;
  UNICHARMAP ids;
  char **script_table;
  int script_table_size_used;
  int script_table_size_reserved;
  // True if the unichars have their tops/bottoms set.
  bool top_bottom_set_;
  // True if the unicharset has significant upper/lower case chars.
  bool script_has_upper_lower_;
  // True if the unicharset has a significant mean-line with significant
  // ascenders above that.
  bool script_has_xheight_;
  // True if the set contains chars that would be changed by the cleanup.
  bool old_style_included_;
 
  // A few convenient script name-to-id mapping without using hash.
  // These are initialized when unicharset file is loaded.  Anything
  // missing from this list can be looked up using get_script_id_from_name.
  int null_sid_;
  int common_sid_;
  int latin_sid_;
  int cyrillic_sid_;
  int greek_sid_;
  int han_sid_;
  int hiragana_sid_;
  int katakana_sid_;
  int thai_sid_;
  int hangul_sid_;
  // The most frequently occurring script in the charset.
  int default_sid_;
};
 
} // namespace tesseract
 
#endif // TESSERACT_CCUTIL_UNICHARSET_H_