vm: tests for generators

ncw · ncw · commit 7c07fd2d9b3c · 2015-05-25T11:01:38.000+01:00
diff --git a/vm/eval.go b/vm/eval.go
@@ -21,10 +21,6 @@ of a code object so a frame doesn't have to be allocated and
 deallocated each time which seems like a good idea.  If we want to
 work with go routines then it might have to be more sophisticated.
 
-To implmenent generators need to check Code.Flags & CO_GENERATOR at
-the start of vmRum and if so wrap the created frame into a generator
-object.
-
 FIXME could make the stack be permanently allocated and just keep a
 pointer into it rather than using append etc...
 
diff --git a/vm/tests/generators.py b/vm/tests/generators.py
@@ -0,0 +1,77 @@
+doc="generator 1"
+def g1():
+    yield 1
+    yield 2
+    yield 3
+i = g1()
+assert next(i) == 1
+assert next(i) == 2
+assert next(i) == 3
+ok = False
+try:
+    next(i)
+except StopIteration:
+    ok = True
+assert ok, "StopIteration not raised"
+
+doc="generator 2"
+def g2():
+    for i in range(5):
+        yield i
+assert tuple(g2()) == (0,1,2,3,4)
+
+doc="yield from"
+def g3():
+    yield "potato"
+    yield from g1()
+    yield "sausage"
+assert tuple(g3()) == ("potato",1,2,3,"sausage")
+
+doc="yield into"
+state = "not started"
+def echo(value=None):
+    """Example from python docs"""
+    global state
+    state = "started"
+    try:
+        while True:
+            try:
+                value = (yield value)
+            except Exception as e:
+                value = e
+    finally:
+        # clean up when close is called
+        state = "finally"
+
+assert state == "not started"
+generator = echo(1)
+
+assert state == "not started"
+
+assert next(generator) == 1
+assert state == "started"
+
+assert next(generator) == None
+assert state == "started"
+
+assert generator.send(2) == 2
+assert state == "started"
+
+assert generator.send(3) == 3
+assert state == "started"
+
+assert next(generator) == None
+assert state == "started"
+
+# FIXME not implemented
+# err = ValueError("potato")
+# e = generator.throw(ValueError, "potato")
+# assert isinstance(e, ValueError)
+# assert state == "started"
+
+# FIXME not implemented
+# generator.close()
+# assert state == "finally"
+
+
+doc="finished"
