--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/tesseract/src/training/unicharset/lang_model_helpers.h	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,84 @@
+// Copyright 2017 Google Inc. All Rights Reserved.
+// Author: rays@google.com (Ray Smith)
+// Purpose: Collection of convenience functions to simplify creation of the
+//          unicharset, recoder, and dawgs for an LSTM model.
+
+// 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_TRAINING_LANG_MODEL_HELPERS_H_
+#define TESSERACT_TRAINING_LANG_MODEL_HELPERS_H_
+
+#include "export.h"
+
+#include "serialis.h"
+#include "tessdatamanager.h"
+#include "unicharset.h"
+
+#include <string>
+
+namespace tesseract {
+
+// Helper makes a filename (<output_dir>/<lang>/<lang><suffix>) and writes data
+// to the file, using writer if not null, otherwise, a default writer.
+// Default writer will overwrite any existing file, but a supplied writer
+// can do its own thing. If lang is empty, returns true but does nothing.
+// NOTE that suffix should contain any required . for the filename.
+TESS_UNICHARSET_TRAINING_API
+bool WriteFile(const std::string &output_dir, const std::string &lang, const std::string &suffix,
+               const std::vector<char> &data, FileWriter writer);
+// Helper reads a file with optional reader and returns a string.
+// On failure emits a warning message and returns and empty string.
+TESS_UNICHARSET_TRAINING_API
+std::string ReadFile(const std::string &filename, FileReader reader = nullptr);
+
+// Helper writes the unicharset to file and to the traineddata.
+bool WriteUnicharset(const UNICHARSET &unicharset, const std::string &output_dir,
+                     const std::string &lang, FileWriter writer, TessdataManager *traineddata);
+// Helper creates the recoder from the unicharset and writes it to the
+// traineddata, with a human-readable form to file at:
+// <output_dir>/<lang>/<lang>.charset_size=<num> for some num being the size
+// of the re-encoded character set. The charset_size file is written using
+// writer if not null, or using a default file writer otherwise, overwriting
+// any existing content.
+// If pass_through is true, then the recoder will be a no-op, passing the
+// unicharset codes through unchanged. Otherwise, the recoder will "compress"
+// the unicharset by encoding Hangul in Jamos, decomposing multi-unicode
+// symbols into sequences of unicodes, and encoding Han using the data in the
+// radical_table_data, which must be the content of the file:
+// langdata/radical-stroke.txt.
+bool WriteRecoder(const UNICHARSET &unicharset, bool pass_through, const std::string &output_dir,
+                  const std::string &lang, FileWriter writer, std::string *radical_table_data,
+                  TessdataManager *traineddata);
+
+// The main function for combine_lang_model.cpp.
+// Returns EXIT_SUCCESS or EXIT_FAILURE for error.
+// unicharset: can be a hand-created file with incomplete fields. Its basic
+//             and script properties will be set before it is used.
+// script_dir: should point to the langdata (github repo) directory.
+// version_str: arbitrary version label.
+// Output files will be written to <output_dir>/<lang>/<lang>.*
+// If pass_through_recoder is true, the unicharset will be used unchanged as
+// labels in the classifier, otherwise, the unicharset will be "compressed" to
+// make the recognition task simpler and faster.
+// The words/puncs/numbers lists may be all empty. If any are non-empty then
+// puncs must be non-empty.
+// lang_is_rtl indicates that the language is generally written from right
+// to left (eg Arabic/Hebrew).
+TESS_UNICHARSET_TRAINING_API
+int CombineLangModel(const UNICHARSET &unicharset, const std::string &script_dir,
+                     const std::string &version_str, const std::string &output_dir,
+                     const std::string &lang, bool pass_through_recoder,
+                     const std::vector<std::string> &words, const std::vector<std::string> &puncs,
+                     const std::vector<std::string> &numbers, bool lang_is_rtl, FileReader reader,
+                     FileWriter writer);
+
+} // namespace tesseract
+
+#endif // TESSERACT_TRAINING_LANG_MODEL_HELPERS_H_