Fix history bigram search when there's no path.

Author: wengxt

src/libime/core/historybigram.cpp

@@ -96,6 +96,8 @@ struct WeightedTrie {
         auto v = trie_.traverse(wordAndCode.first, pos);
         if (TrieType::isValid(v)) {
             result += v;
+        } else if (TrieType::isNoPath(v)) {
+            return 0;
         }
         const char separator[] = {wordCodeSeparator, '\0'};
         v = trie_.traverse(separator, pos);

src/libime/pinyin/pinyinprediction.cpp

@@ -48,12 +48,12 @@ PinyinPrediction::predict(const State &state,
 
     if (lastEncodedPinyin.empty() || sentence.empty()) {
         auto result = Prediction::predictWithScore(state, sentence, maxSize);
-        std::transform(result.begin(), result.end(),
-                       std::back_inserter(finalResult),
-                       [](std::pair<std::string, float> &value) {
-                           return std::make_pair(std::move(value.first),
-                                                 PinyinPredictionSource::Model);
-                       });
+        std::ranges::transform(result, std::back_inserter(finalResult),
+                               [](std::pair<std::string, float> &value) {
+                                   return std::make_pair(
+                                       std::move(value.first),
+                                       PinyinPredictionSource::Model);
+                               });
         return finalResult;
     }
 
@@ -119,11 +119,9 @@ PinyinPrediction::predict(const State &state,
 
                 dup.insert(std::get<std::string>(newItem));
                 intermedidateResult.push_back(std::move(newItem));
-                std::push_heap(intermedidateResult.begin(),
-                               intermedidateResult.end(), cmp);
+                std::ranges::push_heap(intermedidateResult, cmp);
                 while (intermedidateResult.size() > maxSize) {
-                    std::pop_heap(intermedidateResult.begin(),
-                                  intermedidateResult.end(), cmp);
+                    std::ranges::pop_heap(intermedidateResult, cmp);
                     dup.erase(
                         std::get<std::string>(intermedidateResult.back()));
                     intermedidateResult.pop_back();

test/testpinyinprediction.cpp

@@ -10,6 +10,7 @@
 #include "libime/core/userlanguagemodel.h"
 #include "libime/pinyin/pinyindictionary.h"
 #include "libime/pinyin/pinyinencoder.h"
+#include "libime/pinyin/pinyinime.h"
 #include "libime/pinyin/pinyinprediction.h"
 #include "testdir.h"
 
@@ -33,14 +34,21 @@ LogMessageBuilder &operator<<(LogMessageBuilder &log,
 } // namespace fcitx
 
 int main() {
-    UserLanguageModel model(LIBIME_BINARY_DIR "/data/sc.lm");
-    PinyinDictionary dict;
-    dict.load(PinyinDictionary::SystemDict,
-              LIBIME_BINARY_DIR "/data/dict_sc.txt", PinyinDictFormat::Text);
+    PinyinIME ime(
+        std::make_unique<PinyinDictionary>(),
+        std::make_unique<UserLanguageModel>(LIBIME_BINARY_DIR "/data/sc.lm"));
+    ime.setNBest(2);
+    ime.dict()->load(PinyinDictionary::SystemDict,
+                     LIBIME_BINARY_DIR "/data/sc.dict",
+                     PinyinDictFormat::Binary);
+    ime.model()->history().addWithCode({{"可", "JF"}});
+    auto &model = *ime.model();
+    auto &dict = *ime.dict();
 
     PinyinPrediction prediction;
-    prediction.setUserLanguageModel(&model);
-    prediction.setPinyinDictionary(&dict);
+    prediction.setUserLanguageModel(ime.model());
+    prediction.setPinyinDictionary(ime.dict());
+
     auto py = PinyinEncoder::encodeFullPinyin("zhong'guo");
     auto result = prediction.predict(model.nullState(), {"我", "喜欢", "中国"},
                                      {py.data(), py.size()}, 20);