Make "limit" a noop in queries

It is difficult to implement, but not as important for gertty as
for the web UI, so make it a no-op for now.

Change-Id: Idf547e82b14b02bb5d9f12e1fe0b2ca5ab06849f

gertty/search/__init__.py

@@ -62,7 +62,7 @@ class SearchCompiler(object):
 if __name__ == '__main__':
     class Dummy(object):
         pass
-    query = 'reviewer:10068'
+    query = 'status:open limit:50'
     lexer = tokenizer.SearchTokenizer()
     lexer.input(query)
     while True:

gertty/search/parser.py

@@ -76,6 +76,7 @@ def SearchParser():
                 | has_term
                 | is_term
                 | status_term
+                | limit_term
                 | op_term'''
         p[0] = p[1]
 
@@ -302,6 +303,16 @@ def SearchParser():
         else:
             p[0] = gertty.db.change_table.c.status == p[2].upper()
 
+    def p_limit_term(p):
+        '''limit_term : OP_LIMIT NUMBER'''
+        # TODO: Implement this.  The sqlalchemy limit call needs to be
+        # applied to the query operation and so can not be returned as
+        # part of the production here.  The information would need to
+        # be returned out-of-band.  In the mean time, since limits are
+        # not as important in gertty, make this a no-op for now so
+        # that it does not produce a syntax error.
+        p[0] = (True == True)
+
     def p_op_term(p):
         'op_term : OP'
         raise SyntaxError()

gertty/search/tokenizer.py

@@ -36,6 +36,7 @@ operators = {
     'has': 'OP_HAS',
     'is': 'OP_IS',
     'status': 'OP_STATUS',
+    'limit': 'OP_LIMIT',
     }
 
 reserved = {