py: Fix errors are suppressed in generator comprehensions

corona10 · ncw · commit 734fbaa12548 · 2018-11-29T11:15:03.000Z
Sequence.Iterate does not handle exceptions.
Iterate() should return error except StopIteration.
diff --git a/py/sequence.go b/py/sequence.go
@@ -93,10 +93,13 @@ func Iterate(obj Object, fn func(Object) bool) error {
 			return err
 		}
 		for {
-			item, finished := Next(iterator)
-			if finished != nil {
+			item, err := Next(iterator)
+			if err == StopIteration {
 				break
 			}
+			if err != nil {
+				return err
+			}
 			if fn(item) {
 				break
 			}
diff --git a/vm/tests/generators.py b/vm/tests/generators.py
@@ -25,6 +25,14 @@ def g2():
         yield i
 assert tuple(g2()) == (0,1,2,3,4)
 
+doc="generator 3"
+ok = False
+try:
+    list(ax for x in range(10))
+except NameError:
+    ok = True
+assert ok, "NameError not raised"
+
 doc="yield from"
 def g3():
     yield "potato"

Original file line number	Diff line number	Diff line change
`@@ -93,10 +93,13 @@ func Iterate(obj Object, fn func(Object) bool) error {`
`93`	`93`	`return err`
`94`	`94`	`}`
`95`	`95`	`for {`
`96`		`- item, finished := Next(iterator)`
`97`		`- if finished != nil {`
	`96`	`+ item, err := Next(iterator)`
	`97`	`+ if err == StopIteration {`
`98`	`98`	`break`
`99`	`99`	`}`
	`100`	`+ if err != nil {`
	`101`	`+ return err`
	`102`	`+ }`
`100`	`103`	`if fn(item) {`
`101`	`104`	`break`
`102`	`105`	`}`