You really should be looking at the allong.es home page. Or the source code. But here's a cheat sheet:
Makes a function into a variadic (accepts any number of arguments). The last named parameter will be given an array of arguments.
var variadic = require('allong.es').variadic;
var fn = variadic(function (a) { return a })
fn()
//=> []
fn(1, 2, 3)
//=> [1,2,3]
fn = variadic(function (a,b) { return { a: a, b: b } })
fn()
//=> { a: undefined, b: [] }
fn(1)
//=> { a: 1, b: [] }
fn(1,2,3)
//=> { a: 1, b: [2, 3] }Sometimes, you have a function that takes multiple arguments, but you only want it to accept one, or two, or maybe three arguments and ignore the rest. For example, parseInt takes a radix as an optional second parameter. And that is havoc if you try to use it with Array.map:
['1', '2', '3', '4', '5'].map(parseInt)
//=> [ 1,
// NaN,
// NaN,
// NaN,
// NaN ]Use unary(parseInt) to solve the problem:
['1', '2', '3', '4', '5'].map(unary(parseInt))
//=> [ 1, 2, 3, 4, 5 ]binary has similar uses when working with Array.reduce and its habit of passing three parameters to your supplied function.
The basics. Note: applyFirst is faster than applyLeft, use it if you are only applying a single argument. Likewise, applyLast is faster than applyRight.
var applyFirst = require('allong.es').applyFirst,
applyLast = require('allong.es').applyLast,
applyLeft = require('allong.es').applyLeft,
applyRight = require('allong.es').applyRight;
var base = function (greeting, you, me) { return greeting + ', ' + you + ', my name is ' + me }
var hello = applyFirst(base, 'Hello')
hello('Giselle', 'Franka')
//=> "Hello, Giselle, my name is Franka"
var helloTom = applyLeft(base, 'Hello', 'Tom')
helloTom('Harry')
//=> "Hello, Tom, my name is Harry"
var ingrid = applyLast(base, 'Ingrid')
ingrid('Hi', 'Pia')
//=> "Hi, Pia, my name is Ingrid"
var anthonyCarla = applyRight(base, 'Anthony', 'Carla')
anthonyCarla('Yo')
//=> "Yo, Anthony, my name is Carla"Partial application is also useful for methods:
var send = require('allong.es').send;
// sends a message
inventories.map(send('apples'))
//=> [ 0, 240, 24 ]
// sends a message and partially applies an argument
inventories.forEach(send('addApples', 12))var curry = require('allong.es').curry;
curry( function (x, y) { return x } )
//=> function (x) {
// return function (y) {
// return x
// }
// }var bound = require('allong.es').bound;
bound(fn, args...)(obj)
//=> fn.bind(obj, args...)var get = require('allong.es').get;
array.map(get('property'))
//=> array.map(function (element) {
// return element['property']
// })var compose = require('allong.es').compose,
sequence = require('allong.es').sequence;
compose(a, b, c)
//=> function (x) {
// return a(b(c(x)))
// }
sequence(a, b, c)
//=> function (x) {
// return c(b(a(x)))
// }var splat = require('allong.es').splat,
soak = require('allong.es').soak;
var squareList = splat(function (x) { return x * x })
squareList([1, 2, 3, 4])
//=> [1, 4, 9, 16]
var squareTree = soak(function (x) { return x * x })
squareTree([1, 2, [3, 4]])
//=> [1, 4, [9, 16]]Maybe:
var maybe = require('allong.es').maybe;
var safeFirst = maybe(function (arr) { return arr[0] })
safeFirst([1, 2, 3])
//=> 1
safeFirst(null)
//=> nullTap:
var tap = require('allong.es').tap;
tap([1, 2, 3, 4, 5], send('pop'))
//=> [1, 2, 3, 4]Fluent:
var fluent = require('allong.es').fluent;
Role = function () {}
Role.prototype.set = fluent( function (property, name) {
this[property] = name
})
var doomed = new Attrs()
.set('name', "Fredo")
.set('relationship', 'brother')
.set('parts', ['I', 'II'])Once:
var once = require('allong.es').once;
var message = once( function () { console.log("Hello, it's me") })
message()
//=> "Hello, it's me"
message()
//=>
message()
//=>
message()
//=>var mixin = require('allong.es').mixin,
classDecorator = require('allong.es').classDecorator;
function Todo (name) {
var self = this instanceof Todo
? this
: new Todo();
self.name = name || 'Untitled';
self.done = false;
};
Todo.prototype.do = fluent( function () {
this.done = true;
});
Todo.prototype.undo = fluent( function () {
this.done = false;
});
var AddLocation = mixin({
setLocation: fluent( function (location) {
this.location = location;
}),
getLocation: function () { return this.location; }
});
AddLocation.call(Todo.prototype);
// Or use AddLocation(Todo.prototype)
new Todo("Vacuum").setLocation('Home');
//=> { name: 'Vacuum',
// done: false,
// location: 'Home' }
var AndColourCoded = classDecorator({
setColourRGB: fluent( function (r, g, b) {
this.colourCode = { r: r, g: g, b: b };
}),
getColourRGB: function () {
return this.colourCode;
}
});
var ColourTodo = AndColourCoded(Todo);
new ColourTodo('Use More Decorators').setColourRGB(0, 255, 0);
//=> { name: 'Use More Decorators',
// done: false,
// colourCode: { r: 0, g: 255, b: 0 } }Note: classDecorator works with JavaScript constructors that have a default implementation (they work properly with no arguments), and are new-agnostic (they can be called with new or as a normal function). Todo above has both properties.
React
Typescript
Django
Laravel
Facebook
Microsoft
Google
Alibaba
D3
Tencent