From 2b30e44c7845c0e9fccbf2fc0ea535a0c5322d60 Mon Sep 17 00:00:00 2001
From: "Wu, Ke" <wuke@cs.umd.edu>
Date: Thu, 11 Dec 2014 18:51:21 -0500
Subject: Add IgnoredStateSize() to FeatureFunction

---
 decoder/ff.h | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

(limited to 'decoder/ff.h')

diff --git a/decoder/ff.h b/decoder/ff.h
index 3280592e..afa3dbca 100644
--- a/decoder/ff.h
+++ b/decoder/ff.h
@@ -17,11 +17,17 @@ class FeatureFunction {
   friend class ExternalFeature;
  public:
   std::string name_; // set by FF factory using usage()
-  FeatureFunction() : state_size_() {}
-  explicit FeatureFunction(int state_size) : state_size_(state_size) {}
+  FeatureFunction() : state_size_(), ignored_state_size_() {}
+  explicit FeatureFunction(int state_size, int ignored_state_size = 0)
+      : state_size_(state_size), ignored_state_size_(ignored_state_size) {}
   virtual ~FeatureFunction();
   bool IsStateful() const { return state_size_ > 0; }
   int StateSize() const { return state_size_; }
+  // Returns the number of bytes in the state that should be ignored during
+  // search. When non-zero, the last N bytes in the state should be ignored when
+  // splitting a hypernode by the state. This allows the feature function to
+  // store some side data and later retrieve it via the state bytes.
+  int IgnoredStateSize() const { return ignored_state_size_; }
 
   // override this.  not virtual because we want to expose this to factory template for help before creating a FF
   static std::string usage(bool show_params,bool show_details) {
@@ -71,12 +77,17 @@ class FeatureFunction {
                                      SparseVector<double>* estimated_features,
                                      void* context) const;
 
-  // !!! ONLY call this from subclass *CONSTRUCTORS* !!!
+  // !!! ONLY call these from subclass *CONSTRUCTORS* !!!
   void SetStateSize(size_t state_size) {
     state_size_ = state_size;
   }
+
+  void SetIgnoredStateSize(size_t ignored_state_size) {
+    ignored_state_size_ = ignored_state_size;
+  }
+
  private:
-  int state_size_;
+  int state_size_, ignored_state_size_;
 };
 
 #endif
-- 
cgit v1.2.3


From d2c51ae79bca9b7c87f87ff458f77a6f07fff9a6 Mon Sep 17 00:00:00 2001
From: "Wu, Ke" <wuke@cs.umd.edu>
Date: Wed, 17 Dec 2014 10:42:18 -0500
Subject: Warn about possible misuse of IgnoredStateSize() related functions

---
 decoder/ff.h | 7 +++++++
 1 file changed, 7 insertions(+)

(limited to 'decoder/ff.h')

diff --git a/decoder/ff.h b/decoder/ff.h
index afa3dbca..647b4834 100644
--- a/decoder/ff.h
+++ b/decoder/ff.h
@@ -27,6 +27,12 @@ class FeatureFunction {
   // search. When non-zero, the last N bytes in the state should be ignored when
   // splitting a hypernode by the state. This allows the feature function to
   // store some side data and later retrieve it via the state bytes.
+  //
+  // In general, this should not be necessary and it should always be possible
+  // to replace this with a more appropriate design of state (if you find
+  // yourself having to ignore some part of the state, you are most likely
+  // storing redundant information in the state). Be sure that you
+  // understand how this affects ApplyModelSet() before using it.
   int IgnoredStateSize() const { return ignored_state_size_; }
 
   // override this.  not virtual because we want to expose this to factory template for help before creating a FF
@@ -82,6 +88,7 @@ class FeatureFunction {
     state_size_ = state_size;
   }
 
+  // See document of IgnoredStateSize() above.
   void SetIgnoredStateSize(size_t ignored_state_size) {
     ignored_state_size_ = ignored_state_size;
   }
-- 
cgit v1.2.3