litejs/lib/version-compare.js

Single-page application framework

!function(exports) {
	var splitRe = /[-+_.,]+/
	, opRe = /^[<>]=?/
	, letters = "dabr#p"

	exports.versionDiff = versionDiff
	exports.versionMatch = versionMatch

	function toNum(n) {
		return n ? (isNaN(n) ? letters.indexOf(n.charAt(0).toLowerCase()) - 6 : +n) : 0
	}

	function versionDiff(v1, v2) {
		v1 = ("" + v1).split(splitRe)
		v2 = ("" + v2).split(splitRe)
		var diff = v1.length
		, i = v2.length
		, len = diff < i ? i : diff

		for (i = diff = 0; i < len; i++) if (v1[i] != "x" && v2[i] != "x") {
			if (diff = toNum(v1[i]) - toNum(v2[i])) {
				return diff > 0 ? 1 : -1
			}
		}
		return 0
	}

	function versionMatch(actual, expected) {
		var op = expected.match(opRe)
		, diff = versionDiff(actual, op ? expected.slice(op[0].length) : expected)

		return(
			op == "<" ? diff < 0 :
			op == ">" ? diff > 0 :
			op == "<=" ? diff <= 0 :
			op == ">=" ? diff >= 0 :
			!diff
		)
	}
}(this)