Method arrayproto_splice

builtin_array.go:431–530

(call FunctionCall)

}

func (r *Runtime) arrayproto_splice(call FunctionCall) Value {
	o := call.This.ToObject(r)
	length := toLength(o.self.getStr("length", nil))
	actualStart := relToIdx(call.Argument(0).ToInteger(), length)
	var actualDeleteCount int64
	switch len(call.Arguments) {
	case 0:
	case 1:
		actualDeleteCount = length - actualStart
	default:
		actualDeleteCount = min(max(call.Argument(1).ToInteger(), 0), length-actualStart)
	}
	itemCount := max(int64(len(call.Arguments)-2), 0)
	newLength := length - actualDeleteCount + itemCount
	if newLength >= maxInt {
		panic(r.NewTypeError("Invalid array length"))
	}
	a := arraySpeciesCreate(o, actualDeleteCount)
	if src := r.checkStdArrayObj(o); src != nil {
		if dst := r.checkStdArrayObjWithProto(a); dst != nil {
			values := make([]Value, actualDeleteCount)
			copy(values, src.values[actualStart:])
			setArrayValues(dst, values)
		} else {
			for k := int64(0); k < actualDeleteCount; k++ {
				createDataPropertyOrThrow(a, intToValue(k), src.values[k+actualStart])
			}
			a.self.setOwnStr("length", intToValue(actualDeleteCount), true)
		}
		var values []Value
		if itemCount < actualDeleteCount {
			values = src.values
			copy(values[actualStart+itemCount:], values[actualStart+actualDeleteCount:])
			tail := values[newLength:]
			for k := range tail {
				tail[k] = nil
			}
			values = values[:newLength]
		} else if itemCount > actualDeleteCount {
			if int64(cap(src.values)) >= newLength {
				values = src.values[:newLength]
				copy(values[actualStart+itemCount:], values[actualStart+actualDeleteCount:length])
			} else {
				values = make([]Value, newLength)
				copy(values, src.values[:actualStart])
				copy(values[actualStart+itemCount:], src.values[actualStart+actualDeleteCount:])
			}
		} else {
			values = src.values
		}
		if itemCount > 0 {
			copy(values[actualStart:], call.Arguments[2:])
		}
		src.values = values
		src.objCount = len(values)
	} else {
		for k := int64(0); k < actualDeleteCount; k++ {
			from := valueInt(k + actualStart)