add len operator a la Lua

Author: dragoncoder047

json_runner.py

@@ -454,6 +454,7 @@ def op_100_AT(self, left, right):
         except TypeError:
             return [left, right]
 
+    def op_100_HASH(self, left, right): return [left, len(right)]
     def op_200_DOTDOT(self, left, right): return [range(left, right)]
     op_200_to = op_200_DOTDOT
     def op_300_CARET(self, left, right): return [pow(left, right)]