restructure + syntactic sugar implementation

tests/test_primitive.py

@@ -0,0 +1,42 @@
+import py
+
+from simpleparser import parse
+from objmodel import W_NormalObject
+from interpreter import Interpreter
+
+
+def test_primitive():
+    ast = parse("""
+k = 10 $int_add(31)
+""")
+    interpreter = Interpreter()
+    w_module = interpreter.make_module()
+    interpreter.eval(ast, w_module)
+    assert w_module.getvalue("k").value == 41
+
+
+def test_primitive_error():
+    ast = parse("""
+k = 10 $int_add(31, 12)
+""")
+    interpreter = Interpreter()
+    w_module = interpreter.make_module()
+    with py.test.raises(TypeError):
+        interpreter.eval(ast, w_module)
+
+
+def test_loop():
+    ast = parse("""
+def f(x):
+    r = 0
+    while x:
+        r = r $int_add(x)
+        x = x $int_add(-1)
+    r
+y = f(100)
+""")
+    interpreter = Interpreter()
+    w_module = interpreter.make_module()
+    interpreter.eval(ast, w_module)
+    assert w_module.getvalue("y").value == 5050
+