new special return type for the 'box' block

1 files changed, 7 insertions, 3 deletions

diff --git a/TurtleArt/tatype.py b/TurtleArt/tatype.py
index cf7bb03..346eb23 100644
--- a/TurtleArt/tatype.py
+++ b/TurtleArt/tatype.py
@@ -63,6 +63,7 @@ class TypeDisjunction(tuple,Type):
 
 TYPE_OBJECT = Type('object', 0)
 TYPE_BOOL = Type('bool', 5)
+TYPE_BOX = Type('box', 8)  # special type for the unknown content of a box
 TYPE_CHAR = Type('char', 1)
 TYPE_COLOR = Type('color', 2)
 TYPE_FLOAT = Type('float', 3)
@@ -115,9 +116,7 @@ def get_type(x):
             return (get_type(value)[0], True)
     elif isinstance(x, ast.Subscript):
         if x.value == BOX_AST:
-            return (TypeDisjunction((TYPE_OBJECT, TYPE_STRING, TYPE_NUMBER,
-                TYPE_FLOAT, TYPE_INT, TYPE_NUMERIC_STRING, TYPE_CHAR,
-                TYPE_COLOR)), True)
+            return (TYPE_BOX, True)
     elif isinstance(x, ast.Call):
         if isinstance(x.func, ast.Name):
             if x.func.id == 'float':
@@ -172,6 +171,11 @@ TYPE_CONVERTERS = {
     # The relation describing the type hierarchy must be transitive, i.e.
     # converting A -> C must yield the same result as converting A -> B -> C.
     # TYPE_OBJECT is the supertype of everything.
+    TYPE_BOX: {
+        TYPE_FLOAT: float,
+        TYPE_INT: int,
+        TYPE_NUMBER: float,
+        TYPE_STRING: str},
     TYPE_CHAR: {
         TYPE_INT: ord,
         TYPE_STRING: identity},