Add pow builtin

Author: aisk

runtime/builtin_types.go

@@ -546,6 +546,20 @@ func builtinOrd(f *Frame, args Args, _ KWArgs) (*Object, *BaseException) {
 	return NewInt(result).ToObject(), nil
 }
 
+func builtinPower(f *Frame, args Args, kwargs KWArgs) (*Object, *BaseException) {
+	argc := len(args)
+	expectedTypes := []*Type{ObjectType, ObjectType}
+	if argc == 3 {
+		expectedTypes = append(expectedTypes, ObjectType)
+	}
+	if raised := checkFunctionArgs(f, "pow", args, expectedTypes...); raised != nil {
+		return nil, raised
+	}
+	v := args[0]
+	w := args[1]
+	return binaryOp(f, v, w, v.typ.slots.Pow, v.typ.slots.RPow, w.typ.slots.RPow, "** or pow()")
+}
+
 func builtinPrint(f *Frame, args Args, kwargs KWArgs) (*Object, *BaseException) {
 	sep := " "
 	end := "\n"
@@ -787,6 +801,7 @@ func init() {
 		"oct":            newBuiltinFunction("oct", builtinOct).ToObject(),
 		"open":           newBuiltinFunction("open", builtinOpen).ToObject(),
 		"ord":            newBuiltinFunction("ord", builtinOrd).ToObject(),
+		"pow":            newBuiltinFunction("pow", builtinPower).ToObject(),
 		"print":          newBuiltinFunction("print", builtinPrint).ToObject(),
 		"range":          newBuiltinFunction("range", builtinRange).ToObject(),
 		"raw_input":      newBuiltinFunction("raw_input", builtinRawInput).ToObject(),

runtime/builtin_types_test.go

@@ -294,6 +294,8 @@ func TestBuiltinFuncs(t *testing.T) {
 		{f: "ord", args: wrapArgs("foo"), wantExc: mustCreateException(ValueErrorType, "ord() expected a character, but string of length 3 found")},
 		{f: "ord", args: wrapArgs(NewUnicode("волн")), wantExc: mustCreateException(ValueErrorType, "ord() expected a character, but string of length 4 found")},
 		{f: "ord", args: wrapArgs(1, 2, 3), wantExc: mustCreateException(TypeErrorType, "'ord' requires 1 arguments")},
+		{f: "pow", args: wrapArgs(1), wantExc: mustCreateException(TypeErrorType, "'pow' requires 2 arguments")},
+		{f: "pow", args: wrapArgs(2, 3), want: NewInt(8).ToObject()},
 		{f: "range", args: wrapArgs(), wantExc: mustCreateException(TypeErrorType, "'__new__' of 'int' requires 3 arguments")},
 		{f: "range", args: wrapArgs(3), want: newTestList(0, 1, 2).ToObject()},
 		{f: "range", args: wrapArgs(10, 0), want: NewList().ToObject()},