Remove a while loop that is not necessary

parso/pgen2/parse.py

@@ -167,14 +167,12 @@ class PgenParser(object):
         ilabel = token_to_ilabel(self.grammar, type_, value)
         stack = self.stack
 
-        while True:
-            ilabel
         try:
             plan = stack[-1].current_dfa.ilabel_to_plan[ilabel]
         except KeyError:
             self.error_recovery(self.grammar, stack, type_,
                                 value, start_pos, prefix, self.add_token)
-                break
+            return False
 
         stack[-1].current_dfa = plan.next_dfa
         for push in plan.pushes:
@@ -199,6 +197,8 @@ class PgenParser(object):
             except IndexError:
                 # Stack is empty, set the rootnode.
                 self.rootnode = new_node
+                return True
+        return False
 
     def add_token(self, type_, value, start_pos, prefix):
         """Add a token; return True if this is the end of the program."""