1 files changed, 26 insertions, 0 deletions
diff --git a/extractor/vocabulary.cc b/extractor/vocabulary.cc
new file mode 100644
index 00000000..5c379a29
--- /dev/null
+++ b/extractor/vocabulary.cc
@@ -0,0 +1,26 @@
+#include "vocabulary.h"
+
+Vocabulary::~Vocabulary() {}
+
+int Vocabulary::GetTerminalIndex(const string& word) {
+  if (!dictionary.count(word)) {
+    int word_id = words.size();
+    dictionary[word] = word_id;
+    words.push_back(word);
+    return word_id;
+  }
+
+  return dictionary[word];
+}
+
+int Vocabulary::GetNonterminalIndex(int position) {
+  return -position;
+}
+
+bool Vocabulary::IsTerminal(int symbol) {
+  return symbol >= 0;
+}
+
+string Vocabulary::GetTerminalValue(int symbol) {
+  return words[symbol];
+}