YueWen/node_modules/licia/optimizeCb.js

var isUndef = require('./isUndef');
exports = function(fn, ctx, argCount) {
    if (isUndef(ctx)) return fn;
    switch (argCount == null ? 3 : argCount) {
        case 1:
            return function(val) {
                return fn.call(ctx, val);
            };
        case 3:
            return function(val, idx, collection) {
                return fn.call(ctx, val, idx, collection);
            };
        case 4:
            return function(accumulator, val, idx, collection) {
                return fn.call(ctx, accumulator, val, idx, collection);
            };
    }
    return function() {
        return fn.apply(ctx, arguments);
    };
};

module.exports = exports;