From cf55b48ba6fe461d06918a240f1e177ad1eebbd5 Mon Sep 17 00:00:00 2001
From: Matthew Honnibal <honnibal@gmail.com>
Date: Wed, 12 Nov 2014 23:50:12 +1100
Subject: [PATCH] * Switch to predict label on shift. Big increase in accuracy.

---
 spacy/ner/io_moves.pyx | 41 +++++++++++++++++++++++------------------
 1 file changed, 23 insertions(+), 18 deletions(-)

diff --git a/spacy/ner/io_moves.pyx b/spacy/ner/io_moves.pyx
index 94f7c15c8..dc268e4a5 100644
--- a/spacy/ner/io_moves.pyx
+++ b/spacy/ner/io_moves.pyx
@@ -34,23 +34,23 @@ cdef int set_accept_if_oracle(Move* moves, int n, State* s,
         accept_o = False
         if g_start == s.curr.start and g_end == s.i:
             accept_r = True
-            r_label = g_labels[s.curr.start]
             accept_s = False
         elif g_start == s.curr.start and g_end > s.i:
             accept_s = True
+            s_label = s.curr.label
             accept_r = False
         elif g_starts[s.i] == s.i:
             accept_r = True
-            r_label = 0
             accept_s = False
         else:
             accept_r = True
             accept_s = True
-            r_label = 0
+            s_label = s.curr.label
     else:
         accept_r = False
         if g_starts[s.i] == s.i:
             accept_s = True
+            s_label = g_labels[s.i]
             accept_o = False
         else:
             accept_o = True
@@ -60,9 +60,9 @@ cdef int set_accept_if_oracle(Move* moves, int n, State* s,
     for i in range(1, n):
         m = &moves[i]
         if m.action == SHIFT:
-            m.accept = accept_s
+            m.accept = accept_s and m.label == s_label
         elif m.action == REDUCE:
-            m.accept = accept_r and (r_label == 0 or m.label == r_label)
+            m.accept = accept_r
         elif m.action == OUT:
             m.accept = accept_o
         n_accept += m.accept
@@ -77,7 +77,7 @@ cdef int set_accept_if_valid(Move* moves, int n, State* s) except 0:
     moves[0].accept = False
     for i in range(1, n):
         if moves[i].action == SHIFT:
-            moves[i].accept = True
+            moves[i].accept = moves[i].label == s.curr.label or not entity_is_open(s)
         elif moves[i].action == REDUCE:
             moves[i].accept = open_ent
         elif moves[i].action == OUT:
@@ -110,11 +110,16 @@ cdef int transition(State *s, Move* move) except -1:
         s.i += 1
     elif move.action == SHIFT:
         if not entity_is_open(s):
-            begin_entity(s, 0)
+            s.curr.start = s.i
+            s.curr.label = move.label
         s.i += 1
     elif move.action == REDUCE:
-        s.curr.label = move.label
-        end_entity(s)
+        s.curr.end = s.i
+        s.ents[s.j] = s.curr
+        s.j += 1
+        s.curr.start = 0
+        s.curr.label = -1
+        s.curr.end = 0
     else:
         raise ValueError(move.action)
 
@@ -132,16 +137,16 @@ cdef int fill_moves(Move* moves, int n, list entity_types) except -1:
     moves[i].action = MISSING
     moves[i].label = 0
     i += 1
-    moves[i].clas = i
-    moves[i].action = SHIFT
-    moves[i].label = 0
-    i += 1
+    for entity_type in entity_types:
+        moves[i].action = SHIFT
+        moves[i].label = label_names.setdefault(entity_type, len(label_names))
+        moves[i].clas = i
+        i += 1
     moves[i].clas = i
     moves[i].action = OUT
     moves[i].label = 0
     i += 1
-    for entity_type in entity_types:
-        moves[i].action = REDUCE
-        moves[i].label = label_names.setdefault(entity_type, len(label_names))
-        moves[i].clas = i
-        i += 1
+    moves[i].action = REDUCE
+    moves[i].clas = i
+    moves[i].label = 0
+    i += 1