delegation by composition #05

var compose = function() {
    var funcs = arguments;
    return function() {
        var args = arguments;
        for (var i = funcs.length; i --> 0;) {
            args = [funcs[i].apply(this, args)];
        }
        return args[0];
    };
};

var after = function(chr) {
    return function(str) {  // String ==> String
        var index = str.indexOf(chr);
        return (index < 0) ? "" : str.substring(index + 1);
    };
};

var splitOn = function(chr) {
    return function(str) {  // String ==> [String]
        return str.split(chr);
    };
};

var makeObj = function(desc) {  // [String] ==> Object
    return desc.reduce(function(obj, str) {
        var parts = str.split("=");
        obj[parts[0]] = parts[1];
        return obj;
    }, {});
};

var url = "http://example.com/fetch?product=widget&color=red&size=6";

var getConfig = compose(makeObj, splitOn("&"), after("?"));

console.log(getConfig(url));

Each function accept the same type its predecessor generated