Method arrayproto_toSpliced

builtin_array.go:1361–1421

(call FunctionCall)

}

func (r *Runtime) arrayproto_toSpliced(call FunctionCall) Value {
	o := call.This.ToObject(r)
	length := toLength(o.self.getStr("length", nil))
	actualStart := relToIdx(call.Argument(0).ToInteger(), length)
	var actualSkipCount int64
	if len(call.Arguments) == 1 {
		actualSkipCount = length - actualStart
	} else if len(call.Arguments) > 1 {
		actualSkipCount = min(max(call.Argument(1).ToInteger(), 0), length-actualStart)
	}
	itemCount := max(int64(len(call.Arguments)-2), 0)
	newLength := length - actualSkipCount + itemCount
	if newLength >= maxInt {
		panic(r.NewTypeError("Invalid array length"))
	}

	if src := r.checkStdArrayObj(o); src != nil {
		var values []Value
		if itemCount == actualSkipCount {
			values = make([]Value, len(src.values))
			copy(values, src.values)
		} else {
			values = make([]Value, newLength)
			copy(values, src.values[:actualStart])
			copy(values[actualStart+itemCount:], src.values[actualStart+actualSkipCount:])
		}
		if itemCount > 0 {
			copy(values[actualStart:], call.Arguments[2:])
		}
		return r.newArrayValues(values)
	} else {
		a := r.newArrayLength(newLength)
		var i int64
		rl := actualStart + actualSkipCount

		for i < actualStart {
			pi := valueInt(i)
			iValue := nilSafe(o.self.getIdx(pi, nil))
			createDataPropertyOrThrow(a, pi, iValue)
			i++
		}

		if itemCount > 0 {
			for _, item := range call.Arguments[2:] {
				createDataPropertyOrThrow(a, valueInt(i), nilSafe(item))
				i++
			}
		}

		for i < newLength {
			pi := valueInt(i)
			from := valueInt(rl)
			fromValue := nilSafe(o.self.getIdx(from, nil))
			createDataPropertyOrThrow(a, pi, fromValue)
			i++
			rl++
		}