DSL of setValueOf

DSL of setValueOf

function setValueOf(fieldName, obj) {
    var originVal = obj[fieldName] || {};
    var getters = [];
    var builder = {
        inRange: function (collection, findKey) {
            getters.push(function () {
                return _.find(collection, function (i) {
                    return findKey ? (i[findKey] === originVal[findKey]) : (i === originVal);
                });
            });
            return builder;
        },
        otherwise: function (defaultVal) {
            getters.push(function () {
                return defaultVal;
            });
            return builder;
        },
        set: function () {
            for (var i = 0; i < getters.length; i++) {
                var v = getters[i]();
                if (v !== undefined && v !== null) {
                    obj[fieldName] = v;
                    break;
                }
            }
        }
    };
    return builder;
}

var x = {};
x.t = 4;
setValueOf('t', x).inRange([1, 2, 3]).set();
console.log(x.t)

x.t = 4;
setValueOf('t', x).inRange([1, 2, 3]).otherwise(0).set();
console.log(x.t)

x.t = 4;
setValueOf('t', x).inRange([1, 2, 3, 4]).otherwise(0).set();
console.log(x.t);