diff --git a/data/derive_associated_phrases.py b/data/derive_associated_phrases.py
deleted file mode 100644
index 728b42a..0000000
--- a/data/derive_associated_phrases.py
+++ /dev/null
@@ -1,113 +0,0 @@
-import argparse
-from collections import defaultdict
-from dataclasses import dataclass
-from typing import List, Tuple
-import unicodedata
-
-PRAGMA = "# format org.openvanilla.mcbopomofo.sorted"
-MAX_ENTRIES_PER_PREFIX = 60
-EMOJI_SCORE = -8.0
-
-
-@dataclass
-class Entry:
-    reading: str
-    value: str
-    score: float
-
-    _zipped_readings_and_values_computed: bool = False
-    _cached_zipped_readings_and_values: List[Tuple[str, str]] = None
-
-    def associated_phrase_line(self) -> str:
-        """Return a new Entry in the associated pharse format.
-
-        An original entry of `ㄙˋ-ㄗˋ-ㄕㄡˊ-ㄩˇ 四字熟語 -7.28009397`
-        will return a line `四-ㄙˋ-字-ㄗˋ-熟-ㄕㄡˊ-語-ㄩˇ -7.28009397`.
-        """
-        rvs = self.zipped_readings_and_values()
-        if not rvs:
-            return None
-
-        if len(rvs) < 2:
-            return
-
-        parts = [f"{v}-{r}" for r, v in rvs]
-
-        return "%s %.4f" % ("-".join(parts), self.score)
-
-    def zipped_readings_and_values(self) -> List[Tuple[str, str]]:
-        """Returns the readings and values zipped together.
-
-        This only considers the values that entirely consist of Unicode
-        characters of the category "Lo" (Letter, other).
-        """
-        if self._zipped_readings_and_values_computed:
-            return self._cached_zipped_readings_and_values
-
-        self._zipped_readings_and_values_computed = True
-
-        if self.reading.startswith("_"):  # No punctuations
-            return None
-
-        if self.score <= EMOJI_SCORE:  # No emojis or other symbols
-            return None
-
-        if not all(unicodedata.category(c) == "Lo" for c in self.value):
-            # Everything needs to be a Unicode "Lo" character
-            return None
-
-        reading_parts = self.reading.split("-")
-        if len(reading_parts) != len(self.value):
-            return None
-
-        self._cached_zipped_readings_and_values = list(zip(reading_parts, self.value))
-        return self._cached_zipped_readings_and_values
-
-    @classmethod
-    def from_line(cls, line):
-        reading, value, score = line.strip().split(" ")
-        return cls(reading, value, float(score))
-
-
-def main(source_file, target_file):
-    with open(source_file, "r") as f:
-        if f.readline().strip() != PRAGMA:
-            raise ValueError("Invalid source file")
-        lines = [line.strip() for line in f]
-
-    entries = [Entry.from_line(line) for line in lines[1:]]
-
-    prefix_entry_map = defaultdict(list)
-
-    for e in entries:
-        zipped_rvs = e.zipped_readings_and_values()
-        if not zipped_rvs or len(zipped_rvs) < 2:
-            continue
-
-        prefix = f"{zipped_rvs[0][1]}-{zipped_rvs[0][0]}"
-        prefix_entry_map[prefix].append(e)
-
-    output_lines = []
-    keys = sorted(prefix_entry_map.keys(), key=lambda k: k.encode("utf-8"))
-    for k in keys:
-        entries = sorted(prefix_entry_map[k], key=lambda e: e.score, reverse=True)
-
-        output_lines.extend(
-            [e.associated_phrase_line() for e in entries[:MAX_ENTRIES_PER_PREFIX]]
-        )
-
-    byte_sorted_output_lines = sorted(output_lines, key=lambda x: x.encode("utf-8"))
-
-    with open(target_file, "w") as f:
-        print(PRAGMA, file=f)
-        for line in byte_sorted_output_lines:
-            print(line, file=f)
-
-
-if __name__ == "__main__":
-    parser = argparse.ArgumentParser()
-    parser.add_argument("source", help="source file")
-    parser.add_argument("target", help="target file")
-    args = parser.parse_args()
-
-    main(args.source, args.target)
diff --git a/src/Engine/AssociatedPhrasesV2.cpp b/src/Engine/AssociatedPhrasesV2.cpp
index e78a2be..bd6f8c4 100644
--- a/src/Engine/AssociatedPhrasesV2.cpp
+++ b/src/Engine/AssociatedPhrasesV2.cpp
@@ -121,6 +121,8 @@ void AssociatedPhrasesV2::close() {
   mmapedFile_.close();
 }
 
+bool AssociatedPhrasesV2::isLoaded() const { return db_ != nullptr; }
+
 bool AssociatedPhrasesV2::open(std::unique_ptr<ParselessPhraseDB> db) {
   if (db_ != nullptr) {
     return false;
diff --git a/src/Engine/AssociatedPhrasesV2.h b/src/Engine/AssociatedPhrasesV2.h
index 60622eb..916bfce 100644
--- a/src/Engine/AssociatedPhrasesV2.h
+++ b/src/Engine/AssociatedPhrasesV2.h
@@ -40,6 +40,7 @@ class AssociatedPhrasesV2 {
 
   bool open(const char* path);
   void close();
+  bool isLoaded() const;
 
   // Allows the use of existing in-memory db.
   bool open(std::unique_ptr<ParselessPhraseDB> db);
diff --git a/src/Engine/McBopomofoLM.cpp b/src/Engine/McBopomofoLM.cpp
index 8cb1edd..0bb3107 100644
--- a/src/Engine/McBopomofoLM.cpp
+++ b/src/Engine/McBopomofoLM.cpp
@@ -43,7 +43,9 @@ void McBopomofoLM::loadLanguageModel(const char* languageModelDataPath) {
   }
 }
 
-bool McBopomofoLM::isDataModelLoaded() { return languageModel_.isLoaded(); }
+bool McBopomofoLM::isDataModelLoaded() const {
+  return languageModel_.isLoaded();
+}
 
 void McBopomofoLM::loadAssociatedPhrasesV2(const char* associatedPhrasesPath) {
   if (associatedPhrasesPath) {
@@ -64,6 +66,10 @@ void McBopomofoLM::loadUserPhrases(const char* userPhrasesDataPath,
   }
 }
 
+bool McBopomofoLM::isAssociatedPhrasesV2Loaded() const {
+  return associatedPhrasesV2_.isLoaded();
+}
+
 void McBopomofoLM::loadPhraseReplacementMap(const char* phraseReplacementPath) {
   if (phraseReplacementPath) {
     phraseReplacement_.close();
diff --git a/src/Engine/McBopomofoLM.h b/src/Engine/McBopomofoLM.h
index 1492628..888cdd2 100644
--- a/src/Engine/McBopomofoLM.h
+++ b/src/Engine/McBopomofoLM.h
@@ -67,11 +67,13 @@ class McBopomofoLM : public Formosa::Gramambular2::LanguageModel {
   // Loads (or reloads, if already loaded) the primary language model data file.
   void loadLanguageModel(const char* languageModelDataPath);
 
-  bool isDataModelLoaded();
+  bool isDataModelLoaded() const;
 
   // Loads (or reloads if already loaded) the associated phrases data file.
   void loadAssociatedPhrasesV2(const char* associatedPhrasesPath);
 
+  bool isAssociatedPhrasesV2Loaded() const;
+
   // Loads (or reloads if already loaded) both the user phrases and the excluded
   // phrases files. If one argument is passed a nullptr, that file will not
   // be loaded or reloaded.
diff --git a/src/Engine/ParselessLM.cpp b/src/Engine/ParselessLM.cpp
index 4dd5afb..2cd6211 100644
--- a/src/Engine/ParselessLM.cpp
+++ b/src/Engine/ParselessLM.cpp
@@ -34,7 +34,7 @@
 
 namespace McBopomofo {
 
-bool ParselessLM::isLoaded() { return mmapedFile_.data() != nullptr; }
+bool ParselessLM::isLoaded() const { return db_ != nullptr; }
 
 bool ParselessLM::open(const char* path) {
   if (!mmapedFile_.open(path)) {
diff --git a/src/Engine/ParselessLM.h b/src/Engine/ParselessLM.h
index cf9ba91..892bfd2 100644
--- a/src/Engine/ParselessLM.h
+++ b/src/Engine/ParselessLM.h
@@ -42,7 +42,7 @@ class ParselessLM : public Formosa::Gramambular2::LanguageModel {
   ParselessLM& operator=(const ParselessLM&) = delete;
   ParselessLM& operator=(ParselessLM&&) = delete;
 
-  bool isLoaded();
+  bool isLoaded() const;
   bool open(const char* path);
   void close();
 
diff --git a/src/KeyHandler.h b/src/KeyHandler.h
index 3d19165..073d92a 100644
--- a/src/KeyHandler.h
+++ b/src/KeyHandler.h
@@ -235,9 +235,9 @@ class KeyHandler {
   // contain the prefix. This allows the following two scenarios:
   //
   // (1) the current walk is 得 and we want to pin the phrase 得到; in this
-  // case,
-  //     the prefixReading is ㄉㄜˊ and prefixValue is 得, and the associated
-  //     phrase's reading and value are ㄉㄜˊ-ㄉㄠˋ and 得到 respectively.
+  //     case, the prefixReading is ㄉㄜˊ and prefixValue is 得, and the
+  //     associated phrase's reading and value are ㄉㄜˊ-ㄉㄠˋ and 得到
+  //     respectively.
   // (2) the current walk is 得 but we want to pin the phrase 德性, coming from
   //     the choosing-candidate state; in this case, the prefix reading and
   //     value is now ㄉㄜˊ and 德, and the associated phrase is ㄉㄜˊ-ㄒㄧㄥˋ