Add list type safety, helpers; remove cruft

py/dict.go

@@ -217,3 +217,9 @@ func (a StringDict) M__contains__(other Object) (Object, error) {
 	}
 	return False, nil
 }
+
+func (d StringDict) GetDict() StringDict {
+	return d
+}
+
+var _ IGetDict = (*StringDict)(nil)

py/list.go

@@ -41,8 +41,8 @@ func init() {
 
 	ListType.Dict["sort"] = MustNewMethod("sort", func(self Object, args Tuple, kwargs StringDict) (Object, error) {
 		const funcName = "sort"
-		var l *List
-		if self == None {
+		l, isList := self.(*List)
+		if !isList {
 			// method called using `list.sort([], **kwargs)`
 			var o Object
 			err := UnpackTuple(args, nil, funcName, 1, 1, &o)
@@ -60,7 +60,6 @@ func init() {
 			if err != nil {
 				return nil, err
 			}
-			l = self.(*List)
 		}
 		err := SortInPlace(l, kwargs, funcName)
 		if err != nil {
@@ -121,6 +120,15 @@ func NewListFromItems(items []Object) *List {
 	return l
 }
 
+// Makes an argv into a tuple
+func NewListFromStrings(items []string) *List {
+	l := NewListSized(len(items))
+	for i, v := range items {
+		l.Items[i] = String(v)
+	}
+	return l
+}
+
 // Copy a list object
 func (l *List) Copy() *List {
 	return NewListFromItems(l.Items)
@@ -141,6 +149,13 @@ func (l *List) Extend(items []Object) {
 	l.Items = append(l.Items, items...)
 }
 
+// Extend the list with strings
+func (l *List) ExtendWithStrings(items []string) {
+	for _, item := range items {
+		l.Items = append(l.Items, Object(String(item)))
+	}
+}
+
 // Extends the list with the sequence passed in
 func (l *List) ExtendSequence(seq Object) error {
 	return Iterate(seq, func(item Object) bool {

py/traceback.go

@@ -52,7 +52,7 @@ RuntimeError: this is the error message
 func (tb *Traceback) TracebackDump(w io.Writer) {
 	for ; tb != nil; tb = tb.Next {
 		fmt.Fprintf(w, "  File %q, line %d, in %s\n", tb.Frame.Code.Filename, tb.Lineno, tb.Frame.Code.Name)
-		fmt.Fprintf(w, "    %s\n", "FIXME line of source goes here")
+		//fmt.Fprintf(w, "    %s\n", "FIXME line of source goes here")
 	}
 }