restructure + syntactic sugar implementation

tests/test_interpreter.py

@@ -0,0 +1,121 @@
+from simpleparser import parse
+from objmodel import W_NormalObject
+from interpreter import Interpreter
+
+
+#
+# The Interpreter class needs a method 'eval(ast, w_context)' that is
+# doing "AST visiting", as follows:
+#
+#     def eval(self, ast, w_context):
+#         method = getattr(self, "eval_" + ast.__class__.__name__)
+#         return method(ast, w_context)
+#
+# This calls a method called "eval_Xxx" on self for every class
+# called Xxx of the simpleast.py module.
+#
+def test_simplxe():
+    ast = parse("""
+10
+11
+12
+""")
+    w_module = W_NormalObject()
+    interpreter = Interpreter()
+    interpreter.eval(ast, w_module)
+
+
+def test_simple():
+    ast = parse("""
+k = 10
+j = 11
+i = 12
+""")
+    w_module = W_NormalObject()
+    interpreter = Interpreter()
+    interpreter.eval(ast, w_module)
+    assert w_module.getvalue("i").value == 12
+    assert w_module.getvalue("j").value == 11
+    assert w_module.getvalue("k").value == 10
+
+
+def test_if():
+    ast = parse("""
+k = 10
+if k:
+    j = 11
+else:
+    i = 12
+""")
+    w_module = W_NormalObject()
+    interpreter = Interpreter()
+    interpreter.eval(ast, w_module)
+    assert w_module.getvalue("i") is None
+    assert w_module.getvalue("j").value == 11
+    assert w_module.getvalue("k").value == 10
+
+
+def test_def():
+    ast = parse("""
+def f(x, y):
+    if x:
+        x
+    else:
+        y
+i = f(6, 3)
+j = f(0, 9)
+""")
+    w_module = W_NormalObject()
+    interpreter = Interpreter()
+    interpreter.eval(ast, w_module)
+    assert w_module.getvalue("i").value == 6
+    assert w_module.getvalue("j").value == 9
+
+
+def test_object():
+    ast = parse("""
+object x:
+    i = 4
+    j = i
+    object z:
+        i = 5
+""")
+    w_module = W_NormalObject()
+    interpreter = Interpreter()
+    interpreter.eval(ast, w_module)
+    assert w_module.getvalue("x").getvalue("i").value == 4
+    assert w_module.getvalue("x").getvalue("j").value == 4
+    assert w_module.getvalue("x").getvalue("z").getvalue("i").value == 5
+
+
+def test_obscure_recursion():
+    ast = parse("""
+object a:
+    def f(a):
+        if a:
+            x = 5
+            a f(0)
+        else:
+            x = 7
+        x
+i = a f(a)
+""")
+    w_module = W_NormalObject()
+    interpreter = Interpreter()
+    interpreter.eval(ast, w_module)
+    assert w_module.getvalue("i").value == 5
+
+
+def test_assign():
+    ast = parse("""
+object a:
+    b = 5
+    def set(n):
+        self b = n
+a set(7)
+i = a b
+""")
+    w_module = W_NormalObject()
+    interpreter = Interpreter()
+    interpreter.eval(ast, w_module)
+    assert w_module.getvalue("i").value == 7