Use Function First!

This is Functional Programming tool to compose data-first/callback-last styled functions.

Inspired by:
https://thenewcircle.com/s/post/1468/hey_underscore_you_are_doing_it_wrong_brian_lonsdorf
https://www.youtube.com/watch?v=m3svKOdZijA

Underscore style (Data First / Callback Last)

var _ = require('underscore');

var mapFirstTwo = function(data){
    return _.map(data, function(item){
        return _.first(item, 2);
    });
};

Function First / Data Last style

1. Use Function

var use = require('use-function-first');
var underscore = require('underscore');

var mapFirstTwo = use(function(map, first){
    return map( first (2));
}, underscore);

2. Compose Function

var composeFn = require('use-function-first');
var _ = require('underscore');

var mapFirstTwo = composeFn(['map first', 2], _ );

Result

mapFirstTwo(["one","two","three"]); // ["on","tw","th"]

3. File-system API

var filterFiles = composeFn(
    'readdir filter filesOnly',
    require('fs'),
    Array, 
    {filesOnly: function( fileName, callback ){
        
    }}
);

filterFiles("./");