js 的路径处理函数集合

path-join.js

function join(from, to) {
	var part, newPath;
		isAbsolute = from.charAt(0) == '/',
		pathParts = [].concat(from.split('/')).concat(to.split('/')),
		finalParts = [],
		skipNum = 0;

	while( part = pathParts.pop()){
		if(part !== '..' && part !== '.') {
			if(skipNum) {
				skipNum--;
				continue;
			} 
			finalParts.unshift(part);
		} else {
			skipNum += part.length;
		}
	}

	newPath = finalParts.join('/');
	if(isAbsolute) newPath = '/' + newPath;

	return newPath;
}
// Example
var mod2Id = join('ctrl/mod1', './mod2');
var utilId = join('common/moment', '../util');
console.log(mod2Id); // ctrl/util
console.log(utilId); // util

path.js

function