Hooks for online grammar extraction

1 files changed, 25 insertions, 4 deletions

diff --git a/python/pkg/cdec/sa/extract.py b/python/pkg/cdec/sa/extract.py
index b7d2fe6e..d1861101 100644
--- a/python/pkg/cdec/sa/extract.py
+++ b/python/pkg/cdec/sa/extract.py
@@ -9,6 +9,8 @@ import signal
 import cdec.sa
 
 extractor, prefix = None, None
+online = False
+
 def make_extractor(config, grammars, features):
     global extractor, prefix
     signal.signal(signal.SIGINT, signal.SIG_IGN) # Let parent process catch Ctrl+C
@@ -25,22 +27,37 @@ def load_features(features):
         sys.path.remove(prefix)
 
 def extract(inp):
-    global extractor, prefix
+    global extractor, prefix, online
     i, sentence = inp
     sentence = sentence[:-1]
     fields = re.split('\s*\|\|\|\s*', sentence)
     suffix = ''
-    if len(fields) > 1:
-        sentence = fields[0]
-        suffix = ' ||| ' + ' ||| '.join(fields[1:])
+    # 3 fields for online mode, 1 for normal
+    if online:
+        if len(fields) < 3:
+            sys.stderr.write('Error: online mode requires references and alignments.'
+                    '  Not adding sentence to training data: {0}\n'.format(sentence))
+            sentence = fields[0]
+        else:
+            sentence, reference, alignment = fields[0:3]
+        if len(fields) > 3:
+            suffix = ' ||| ' + ' ||| '.join(fields[3:])
+    else:
+        if len(fields) > 1:
+            sentence = fields[0]
+            suffix = ' ||| ' + ' ||| '.join(fields[1:])
     grammar_file = os.path.join(prefix, 'grammar.{0}'.format(i))
     with open(grammar_file, 'w') as output:
         for rule in extractor.grammar(sentence):
             output.write(str(rule)+'\n')
+    # Add training instance _after_ extracting grammars
+    if online:
+        extractor.add_instance(sentence, reference, alignment)
     grammar_file = os.path.abspath(grammar_file)
     return '<seg grammar="{0}" id="{1}"> {2} </seg>{3}'.format(grammar_file, i, sentence, suffix)
 
 def main():
+    global online
     logging.basicConfig(level=logging.INFO)
     parser = argparse.ArgumentParser(description='Extract grammars from a compiled corpus.')
     parser.add_argument('-c', '--config', required=True,
@@ -53,6 +70,8 @@ def main():
                         help='number of sentences / chunk')
     parser.add_argument('-f', '--features', nargs='*', default=[],
                         help='additional feature definitions')
+    parser.add_argument('-o', '--online', action='store_true', default=False,
+                        help='online grammar extraction')
     args = parser.parse_args()
 
     if not os.path.exists(args.grammars):
@@ -63,6 +82,8 @@ def main():
                     ' should be a python module\n'.format(featdef))
             sys.exit(1)
     
+    online = args.online
+    
     if args.jobs > 1:
         logging.info('Starting %d workers; chunk size: %d', args.jobs, args.chunksize)
         pool = mp.Pool(args.jobs, make_extractor, (args.config, args.grammars, args.features))