Adding __iter__ and items methods to Dict

kellrott · ncw · commit 7f6244eb3f6e · 2019-06-03T17:39:21.000+01:00
diff --git a/py/dict.go b/py/dict.go
@@ -27,6 +27,17 @@ var (
 	expectingDict  = ExceptionNewf(TypeError, "a dict is required")
 )
 
+func init() {
+	StringDictType.Dict["items"] = MustNewMethod("items", func(self Object, args Tuple) (Object, error) {
+		sMap := self.(StringDict)
+		o := make([]Object, 0, len(sMap))
+		for k, v := range sMap {
+			o = append(o, Tuple{String(k), v})
+		}
+		return NewIterator(o), nil
+	}, 0, "items() -> list of D's (key, value) pairs, as 2-tuples")
+}
+
 // String to object dictionary
 //
 // Used for variables etc where the keys can only be strings
@@ -100,6 +111,15 @@ func (a StringDict) M__repr__() (Object, error) {
 	return String(out.String()), nil
 }
 
+// Returns a list of keys from the dict
+func (d StringDict) M__iter__() (Object, error) {
+	o := make([]Object, 0, len(d))
+	for k := range d {
+		o = append(o, String(k))
+	}
+	return NewIterator(o), nil
+}
+
 func (d StringDict) M__getitem__(key Object) (Object, error) {
 	str, ok := key.(String)
 	if ok {
diff --git a/py/tests/dict.py b/py/tests/dict.py
@@ -12,4 +12,20 @@
 a = repr({"a":"b","c":5.5})
 assert a == "{'a': 'b', 'c': 5.5}" or a == "{'c': 5.5, 'a': 'b'}"
 
+doc="check __iter__"
+a = {"a":"b","c":5.5}
+l =  list(iter(a))
+assert "a" in l
+assert "c" in l
+assert len(l) == 2
+
+doc="check items"
+a = {"a":"b","c":5.5}
+for k, v in a.items():
+    assert k in ["a", "c"]
+    if k == "a":
+        assert v == "b"
+    if k == "c":
+        assert v == 5.5
+
 doc="finished"
