able to load pickled structures

src/syntactic_structure.py

@@ -1,5 +1,6 @@
 from xml.etree import ElementTree
 import logging
+import pickle
 
 from component import Component, ComponentType
 from lemma_features import get_lemma_features
@@ -92,7 +93,12 @@ class SyntacticStructure:
         return [] if matches is None else matches
 
 
-def build_structures(filename):
+def build_structures(args):
+    filename = args.structures
+    if args.pickled_structures:
+        with open(filename, 'rb') as fp:
+            return pickle.load(fp)
+
     max_num_components = -1
     with open(filename, 'r') as fp:
         et = ElementTree.XML(fp.read())