Support French in TTS (#397)

 cmake_minimum_required(VERSION 3.13 FATAL_ERROR)
 project(sherpa-onnx)
 
-set(SHERPA_ONNX_VERSION "1.8.6")
+set(SHERPA_ONNX_VERSION "1.8.7")
 
 # Disable warning about
 #

@@ -133,6 +133,8 @@ std::vector<int64_t> Lexicon::ConvertTextToTokenIds(
       return ConvertTextToTokenIdsGerman(text);
     case Language::kSpanish:
       return ConvertTextToTokenIdsSpanish(text);
+    case Language::kFrench:
+      return ConvertTextToTokenIdsFrench(text);
     case Language::kChinese:
       return ConvertTextToTokenIdsChinese(text);
     default:
@@ -254,6 +256,8 @@ void Lexicon::InitLanguage(const std::string &_lang) {
     language_ = Language::kGerman;
   } else if (lang == "spanish") {
     language_ = Language::kSpanish;
+  } else if (lang == "french") {
+    language_ = Language::kFrench;
   } else if (lang == "chinese") {
     language_ = Language::kChinese;
   } else {

@@ -46,6 +46,11 @@ class Lexicon {
     return ConvertTextToTokenIdsEnglish(text);
   }
 
+  std::vector<int64_t> ConvertTextToTokenIdsFrench(
+      const std::string &text) const {
+    return ConvertTextToTokenIdsEnglish(text);
+  }
+
   std::vector<int64_t> ConvertTextToTokenIdsEnglish(
       const std::string &text) const;
 
@@ -62,6 +67,7 @@ class Lexicon {
     kEnglish,
     kGerman,
     kSpanish,
+    kFrench,
     kChinese,
     kUnknown,
   };

@@ -164,7 +164,7 @@ template bool SplitStringToFloats(const std::string &full, const char *delim,
                                   std::vector<double> *out);
 
 static bool IsPunct(char c) { return c != '\'' && std::ispunct(c); }
-static bool IsGermanUmlauts(const std::string &word) {
+static bool IsGermanUmlaut(const std::string &word) {
   // ä 0xC3 0xA4
   // ö 0xC3 0xB6
   // ü 0xC3 0xBC
@@ -187,6 +187,7 @@ static bool IsGermanUmlauts(const std::string &word) {
 }
 
 // see https://www.tandem.net/blog/spanish-accents
+// https://www.compart.com/en/unicode/U+00DC
 static bool IsSpanishDiacritic(const std::string &word) {
   // á 0xC3 0xA1
   // é 0xC3 0xA9
@@ -195,6 +196,16 @@ static bool IsSpanishDiacritic(const std::string &word) {
   // ú 0xC3 0xBA
   // ü 0xC3 0xBC
   // ñ 0xC3 0xB1
+  //
+  // uppercase
+  //
+  // Á 0xC3 0x81
+  // É 0xC3 0x89
+  // Í 0xC3 0x8D
+  // Ó 0xC3 0x93
+  // Ú 0xC3 0x9A
+  // Ü 0xC3 0x9C
+  // Ñ 0xC3 0x91
 
   if (word.size() != 2 || static_cast<uint8_t>(word[0]) != 0xc3) {
     return false;
@@ -202,15 +213,86 @@ static bool IsSpanishDiacritic(const std::string &word) {
 
   auto c = static_cast<uint8_t>(word[1]);
   if (c == 0xa1 || c == 0xa9 || c == 0xad || c == 0xb3 || c == 0xba ||
-      c == 0xbc || c == 0xb1) {
+      c == 0xbc || c == 0xb1 || c == 0x81 || c == 0x89 || c == 0x8d ||
+      c == 0x93 || c == 0x9a || c == 0x9c || c == 0x91) {
     return true;
   }
 
   return false;
 }
 
+// see https://www.busuu.com/en/french/accent-marks
+static bool IsFrenchDiacritic(const std::string &word) {
+  // acute accent
+  // é 0xC3 0xA9
+  //
+  // grave accent
+  // à 0xC3 0xA0
+  // è 0xC3 0xA8
+  // ù 0xC3 0xB9
+  //
+  // cedilla
+  // ç 0xC3 0xA7
+  //
+  // circumflex
+  // â 0xC3 0xA2
+  // ê 0xC3 0xAA
+  // î 0xC3 0xAE
+  // ô 0xC3 0xB4
+  // û 0xC3 0xBB
+  //
+  // trema
+  // ë 0xC3 0xAB
+  // ï 0xC3 0xAF
+  // ü 0xC3 0xBC
+  //
+  // É 0xC3 0x89
+  //
+  // À 0xC3 0x80
+  // È 0xC3 0x88
+  // Ù 0xC3 0x99
+  // Ç 0xC3 0x87
+  // Â 0xC3 0x82
+  // Ê 0xC3 0x8A
+  // Î 0xC3 0x8E
+  // Ô 0xC3 0x94
+  // Û 0xC3 0x9B
+  // Ë 0xC3 0x8B
+  // Ï 0xC3 0x8F
+  // Ü 0xC3 0x9C
+
+  if (word.size() != 2 || static_cast<uint8_t>(word[0]) != 0xc3) {
+    return false;
+  }
+
+  auto c = static_cast<uint8_t>(word[1]);
+  if (c == 0xa9 || c == 0xa0 || c == 0xa8 || c == 0xb9 || c == 0xa7 ||
+      c == 0xa2 || c == 0xaa || c == 0xae || c == 0xb4 || c == 0xbb ||
+      c == 0xab || c == 0xaf || c == 0xbc || c == 0x89 || c == 0x80 ||
+      c == 0x88 || c == 0x99 || c == 0x87 || c == 0x82 || c == 0x8a ||
+      c == 0x8e || c == 0x94 || c == 0x9b || c == 0x8b || c == 0x8f ||
+      c == 0x9c) {
+    return true;
+  }
+  return false;
+}
+
 static bool IsSpecial(const std::string &w) {
-  return IsGermanUmlauts(w) || IsSpanishDiacritic(w);
+  bool ans = IsGermanUmlaut(w) || IsSpanishDiacritic(w) || IsFrenchDiacritic(w);
+
+  // for french d’impossible
+  // ’ 0xE2 0x80 0x99
+  bool ans2 = false;
+  if (w.size() == 3) {
+    auto c0 = static_cast<uint8_t>(w[0]);
+    auto c1 = static_cast<uint8_t>(w[1]);
+    auto c2 = static_cast<uint8_t>(w[2]);
+    if (c0 == 0xe2 && c1 == 0x80 && c2 == 0x99) {
+      ans2 = true;
+    }
+  }
+
+  return ans || ans2;
 }
 
 static std::vector<std::string> MergeCharactersIntoWords(