The source code

    /**
     * @ignore
     * Declare config info for KISSY.
     * @author yiminghe@gmail.com
     */
    (function (S, undefined) {

        var Loader = S.Loader,
            utils = Loader.Utils,
            host = S.Env.host,
            location = host.location,
            simulatedLocation,
            locationHref,
            configFns = S.Config.fns;

        if (!S.Env.nodejs && location && (locationHref = location.href)) {
            simulatedLocation = new S.Uri(locationHref)
        }

        /*
         modify current module path

         [
         [/(.+-)min(.js(\?t=\d+)?)$/, '$1$2'],
         [/(.+-)min(.js(\?t=\d+)?)$/, function(_,m1,m2){
         return m1+m2;
         }]
         ]

         */
        configFns.map = function (rules) {
            var Config = this.Config;
            if (rules === false) {
                return Config.mappedRules = [];
            }
            return Config.mappedRules = (Config.mappedRules || []).concat(rules || []);
        };

        configFns.mapCombo = function (rules) {
            var Config = this.Config;
            if (rules === false) {
                return Config.mappedComboRules = [];
            }
            return Config.mappedComboRules = (Config.mappedComboRules || []).concat(rules || []);
        };

        /*
         包声明
         biz -> .
         表示遇到 biz/x
         在当前网页路径找 biz/x.js
         @private
         */
        configFns.packages = function (cfgs) {
            var name,
                Config = this.Config,
                ps = Config.packages = Config.packages || {};
            if (cfgs) {
                S.each(cfgs, function (cfg, key) {
                    // 兼容数组方式
                    name = cfg.name || key;

                    // 兼容 path
                    var baseUri = normalizeBase(cfg.base || cfg.path);

                    cfg.name = name;
                    cfg.base = baseUri.toString();
                    cfg.baseUri = baseUri;
                    cfg.runtime = S;
                    delete cfg.path;
                    ps[name] = new Loader.Package(cfg);
                });
                return undefined;
            } else if (cfgs === false) {
                Config.packages = {
                };
                return undefined;
            } else {
                return ps;
            }
        };

        /*
         只用来指定模块依赖信息.
         <code>

         KISSY.config({
         base: '',
         // dom-min.js
         debug: '',
         combine: true,
         tag: '',
         packages: {
         'biz1': {
         // path change to base
         base: 'haha',
         // x.js
         debug: '',
         tag: '',
         combine: false,
         }
         },
         modules: {
         'biz1/main': {
         requires: ['biz1/part1', 'biz1/part2']
         }
         }
         });
         */
        configFns.modules = function (modules) {
            var self = this,
                Env = self.Env;
            if (modules) {
                S.each(modules, function (modCfg, modName) {
                    utils.createModuleInfo(self, modName, modCfg);
                    S.mix(Env.mods[modName], modCfg);
                });
            }
        };

        /*
         KISSY 's base path.
         */
        configFns.base = function (base) {
            var self = this,
                Config = self.Config,
                baseUri;
            if (!base) {
                return Config.base;
            }
            baseUri = normalizeBase(base);
            Config.base = baseUri.toString();
            Config.baseUri = baseUri;
            return undefined;
        };

        function normalizeBase(base) {
            var baseUri;
            if (!S.endsWith(base, '/')) {
                base += '/';
            }
            if (simulatedLocation) {
                baseUri = simulatedLocation.resolve(base);
            } else {
                // add scheme for S.Uri
                // currently only for nodejs
                if (!S.startsWith(base, 'file:')) {
                    base = 'file:' + base;
                }
                baseUri = new S.Uri(base);
            }
            return baseUri;
        }

    })(KISSY);