1 files changed, 8 insertions, 0 deletions
diff --git a/decoder/ff.h b/decoder/ff.h
index 904b9eb8..e470f9a9 100644
--- a/decoder/ff.h
+++ b/decoder/ff.h
@@ -52,6 +52,10 @@ public:
   // stateless feature that doesn't depend on source span: override and return true.  then your feature can be precomputed over rules.
   virtual bool rule_feature() const { return false; }
 
+  // called once, per input, before any feature calls to TraversalFeatures, etc.
+  // used to initialize sentence-specific data structures
+  virtual void PrepareForInput(const SentenceMetadata& smeta);
+
   //OVERRIDE THIS:
   virtual Features features() const { return single_feature(FD::Convert(name_)); }
   // returns the number of bytes of context that this feature function will
@@ -274,6 +278,10 @@ class ModelSet {
                         Hypergraph::Edge* edge,
                         SentenceMetadata const& smeta) const;
 
+  // this is called once before any feature functions apply to a hypergraph
+  // it can be used to initialize sentence-specific data structures
+  void PrepareForInput(const SentenceMetadata& smeta);
+
   bool empty() const { return models_.empty(); }
 
   bool stateless() const { return !state_size_; }