// Copyright 2009 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package unicode // IsDigit reports whether the rune is a decimal digit. func IsDigit(rune int) bool { if rune < 0x100 { // quick ASCII (Latin-1, really) check return '0' <= rune && rune <= '9' } return Is(Digit, rune) }