fix feature name splitting to split on last colon

mert/FeatureDataIterator.cpp

@@ -71,7 +71,7 @@ void FeatureDataIterator::readNext() {
       StringPiece line = m_in->ReadLine();
       m_next.push_back(FeatureDataItem());
       for (TokenIter<AnyCharacter, true> token(line, AnyCharacter(" \t")); token; ++token) {
-        TokenIter<AnyCharacter,false> value(*token,AnyCharacter(":"));
+        TokenIter<AnyCharacterLast,false> value(*token,AnyCharacterLast(":"));
         if (!value) throw FileFormatException(m_in->FileName(), line.as_string());
         StringPiece first = *value;
         ++value;

util/tokenize_piece.hh

@@ -87,6 +87,22 @@ class AnyCharacter {
       return StringPiece(std::find_first_of(in.data(), in.data() + in.size(), chars_.data(), chars_.data() + chars_.size()), 1);
     }
 
+    StringPiece FindLast(const StringPiece &in) const {
+      return StringPiece(std::find_end(in.data(), in.data() + in.size(), chars_.data(), chars_.data() + chars_.size()), 1);
+    }
+
+  private:
+    StringPiece chars_;
+};
+
+class AnyCharacterLast {
+  public:
+    explicit AnyCharacterLast(const StringPiece &chars) : chars_(chars) {}
+
+    StringPiece Find(const StringPiece &in) const {
+      return StringPiece(std::find_end(in.data(), in.data() + in.size(), chars_.data(), chars_.data() + chars_.size()), 1);
+    }
+
   private:
     StringPiece chars_;
 };