construct proper ASTs for type conversion

1 files changed, 16 insertions, 12 deletions

diff --git a/TurtleArt/taprimitive.py b/TurtleArt/taprimitive.py
index 8171c43..baaa9e0 100644
--- a/TurtleArt/taprimitive.py
+++ b/TurtleArt/taprimitive.py
@@ -361,15 +361,9 @@ class Primitive(object):
                                  % (str(self.func.__func__.__name__),
                                     len(new_arg_asts)))
 
+        # type conversion
         elif self == Primitive.convert_for_cmp:
-            # remove the 'convert_to_ast' keyword argument
-            my_kwarg_asts = {}
-            for (key, value) in new_kwarg_asts.iteritems():
-                if key != 'convert_to_ast':
-                    my_kwarg_asts[key] = value
-            return Primitive.convert_for_cmp(*new_arg_asts,
-                                             convert_to_ast=True,
-                                             **my_kwarg_asts)
+            return Primitive.convert_for_cmp(*new_arg_asts, **new_kwarg_asts)
 
         # identity
         elif self == Primitive.identity:
@@ -630,15 +624,25 @@ class Primitive(object):
         return not arg
 
     @staticmethod
-    def convert_for_cmp(value, decimal_point='.', convert_to_ast=False):
-        """ Convert value such that it can be compared to something else.
+    def convert_for_cmp(value, decimal_point='.'):
+        """ Convert value such that it can be compared to something else. If
+        value is an AST, another AST is wrapped around it to represent the
+        conversion, e.g.,
+            Str(s='a') -> Call(func=Name('ord'), args=[Str(s='a')])
         1. Convert a string containing a number into a float.
         2. Convert a single character to its ASCII integer value.
         3. Return all other values unchanged. """
         converted = None
         conversion_ast = None
-        if convert_to_ast:
-            value_ast = value_to_ast(value)
+        convert_to_ast = False
+        if isinstance(value, ast.AST):
+            convert_to_ast = True
+            value_ast = value
+            value = None
+            if isinstance(value_ast, ast.Str):
+                value = value_ast.s
+        if isinstance(decimal_point, ast.Str):
+            decimal_point = decimal_point.s
 
         if isinstance(value, basestring):
             # 1. string containing a number