use utility function for extracting values out of ASTs

  - Fix a bug that was accidentally introduced in one of the previous commits.

1 files changed, 18 insertions, 42 deletions

diff --git a/TurtleArt/taprimitive.py b/TurtleArt/taprimitive.py
index e05460b..1fbeac9 100644
--- a/TurtleArt/taprimitive.py
+++ b/TurtleArt/taprimitive.py
@@ -588,25 +588,15 @@ class Primitive(object):
         Otherwise, convert both to a number. (Colors are converted to an
         integer before they are converted to a string.) """
         convert_to_ast = False
+        (value1_ast, value2_ast) = (None, None)
 
-        def _get_value_and_ast(val):
-            if isinstance(val, ast.AST):
-                val_ast = val
-                val = None
-                if isinstance(val_ast, ast.Num):
-                    val = val_ast.n
-                elif isinstance(val_ast, ast.Str):
-                    val = val_ast.s
-                elif isinstance(val_ast, ast.List):
-                    val = val_ast.elts
-                elif (isinstance(val_ast, ast.Name) and
-                      val_ast.id.startswith("CONSTANTS[")):
-                    val = eval(val_ast.id)
-                return (val, val_ast, True)
-            else:
-                return (val, None, False)
-        (value1, value1_ast, convert_to_ast) = _get_value_and_ast(value1)
-        (value2, value2_ast, convert_to_ast) = _get_value_and_ast(value2)
+        if isinstance(value1, ast.AST):
+            convert_to_ast = True
+            value1_ast = value1
+            value1 = ast_to_value(value1_ast)
+        if isinstance(value2, ast.AST):
+            value2_ast = value2
+            value2 = ast_to_value(value2_ast)
 
         def _to_string(val, val_ast):
             """ Return strings as they are, convert Colors to an integer and
@@ -687,16 +677,9 @@ class Primitive(object):
         if isinstance(value, ast.AST):
             convert_to_ast = True
             value_ast = value
-            value = None
-            if isinstance(value_ast, ast.Str):
-                value = value_ast.s
-            elif isinstance(value_ast, ast.List):
-                value = value_ast.elts
-            elif (isinstance(value_ast, ast.Name) and
-                  value_ast.id.startswith("CONSTANTS[")):
-                value = eval(value_ast.id)
-        if isinstance(decimal_point, ast.Str):
-            decimal_point = decimal_point.s
+            value = ast_to_value(value_ast)
+        if isinstance(decimal_point, ast.AST):
+            decimal_point = ast_to_value(decimal_point)
 
         # 2./3. string
         if isinstance(value, basestring):
@@ -816,11 +799,9 @@ class Primitive(object):
         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
+            value = ast_to_value(value_ast)
+        if isinstance(decimal_point, ast.AST):
+            decimal_point = ast_to_value(decimal_point)
 
         if isinstance(value, basestring):
             # 1. string containing a number
@@ -873,13 +854,6 @@ class Primitive(object):
 
 
 
-class PrimitiveCall(Primitive):
-    """ Primitive that is called when it is a constant argument to another
-    Primitive. """
-    pass
-
-
-
 def is_instancemethod(method):
     # TODO how to access the type `instancemethod` directly?
     return type(method).__name__ == "instancemethod"
@@ -923,7 +897,10 @@ def value_to_ast(value, *args_for_prim, **kwargs_for_prim):
         return ast.List(elts=ast_list, ctx=ast.Load)
     elif isinstance(value, Color):
         if str(value) in CONSTANTS:
-            return ast.Name(id='CONSTANTS[%s]' % repr(value), ctx=ast.Load)
+            # repr(str(value)) is necessary; it first converts the Color to a
+            # string and then adds appropriate quotes around that string
+            return ast.Name(id='CONSTANTS[%s]' % repr(str(value)),
+                            ctx=ast.Load)
         else:
             # call to the Color constructor with this object's values,
             # e.g., Color('red', 0, 50, 100)
@@ -932,7 +909,6 @@ def value_to_ast(value, *args_for_prim, **kwargs_for_prim):
     else:
         raise ValueError("unknown type of raw value: " + repr(type(value)))
 
-# TODO replace every fiddling with a call to this function
 def ast_to_value(ast_object):
     """ Retrieve the value out of a value AST. Supported AST types:
     Num, Str, Name, List, Tuple, Set