From f729164c01ffcab3ca6bcf0f52be9e67ffa9de6e Mon Sep 17 00:00:00 2001
From: Matthew Honnibal <honnibal@gmail.com>
Date: Mon, 16 Mar 2015 08:32:23 -0400
Subject: [PATCH] * Fix bug in label assignment: ensure null-label transitions
 receive the label 0

---
 spacy/syntax/arc_eager.pyx         | 4 ++--
 spacy/syntax/ner.pyx               | 6 +++---
 spacy/syntax/transition_system.pyx | 2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/spacy/syntax/arc_eager.pyx b/spacy/syntax/arc_eager.pyx
index e5a7406f6..2c1157216 100644
--- a/spacy/syntax/arc_eager.pyx
+++ b/spacy/syntax/arc_eager.pyx
@@ -42,8 +42,8 @@ cdef get_cost_func_t[N_MOVES] get_cost_funcs
 cdef class ArcEager(TransitionSystem):
     @classmethod
     def get_labels(cls, gold_parses):
-        move_labels = {SHIFT: {'ROOT': True}, REDUCE: {'ROOT': True}, RIGHT: {},
-                       LEFT: {}, BREAK: {'ROOT': True}}
+        move_labels = {SHIFT: {'': True}, REDUCE: {'': True}, RIGHT: {},
+                       LEFT: {}, BREAK: {'': True}}
         for raw_text, segmented, (ids, tags, heads, labels, iob) in gold_parses:
             for i, (head, label) in enumerate(zip(heads, labels)):
                 if label != 'ROOT':
diff --git a/spacy/syntax/ner.pyx b/spacy/syntax/ner.pyx
index c4ead8258..38c211781 100644
--- a/spacy/syntax/ner.pyx
+++ b/spacy/syntax/ner.pyx
@@ -70,8 +70,8 @@ cdef int _is_valid(int act, int label, const State* s) except -1:
 cdef class BiluoPushDown(TransitionSystem):
     @classmethod
     def get_labels(cls, gold_tuples):
-        move_labels = {MISSING: {'ROOT': True}, BEGIN: {}, IN: {}, LAST: {}, UNIT: {},
-                       OUT: {'ROOT': True}}
+        move_labels = {MISSING: {'': True}, BEGIN: {}, IN: {}, LAST: {}, UNIT: {},
+                       OUT: {'': True}}
         moves = ('M', 'B', 'I', 'L', 'U')
         for (raw_text, toks, (ids, tags, heads, labels, biluo)) in gold_tuples:
             for i, ner_tag in enumerate(biluo):
@@ -99,7 +99,7 @@ cdef class BiluoPushDown(TransitionSystem):
             label = 0
         elif '-' in name:
             move_str, label_str = name.split('-', 1)
-            label = self.label_ids[label_str]
+            label = self.strings[label_str]
         else:
             move_str = name
             label = 0
diff --git a/spacy/syntax/transition_system.pyx b/spacy/syntax/transition_system.pyx
index 72e9cedf8..820b61426 100644
--- a/spacy/syntax/transition_system.pyx
+++ b/spacy/syntax/transition_system.pyx
@@ -21,7 +21,7 @@ cdef class TransitionSystem:
         self.strings = string_table
         for action, label_strs in sorted(labels_by_action.items()):
             for label_str in sorted(label_strs):
-                label_id = self.strings[unicode(label_str)]
+                label_id = self.strings[unicode(label_str)] if label_str else 0
                 moves[i] = self.init_transition(i, int(action), label_id)
                 i += 1
         self.c = moves