zspecza’s gists

zspecza / setArity.js

Last active December 6, 2016 02:29

sets the length property of a given function to the given arity

	function setArity (arity, fn) {
	if (typeof setArity.cache === 'undefined') {
	setArity.cache = {}
	}
	if (typeof setArity.cache[arity] === 'undefined') {
	setArity.cache[arity] = (fn) => {
	switch (arity) {
	case 0: return function () { return fn.apply(this, arguments) }
	case 1: return function (a) { return fn.apply(this, arguments) }
	case 2: return function (a, b) { return fn.apply(this, arguments) }

zspecza / curryN.js

Last active April 12, 2017 18:13

curryN with placeholder support (not optimized)

	// this file is just so I can reference the idea behind placeholders - if you want a maintained version, check out:
	// - https://github.com/thisables/curry
	// - http://ramdajs.com

	const __ = Symbol

	const ARITIES = {}

	const setArity = (arity, fn) => {
	if (!ARITIES[arity]) {

zspecza / composition.js

Created November 16, 2016 21:26

	const users = {
	1: { name: 'bob' },
	2: { name: 'sally' }
	}

	const posts = [
	{ author: 'sally', title: 'Hello World' },
	{ author: 'bob', title: 'How to do stuff' }
	]

zspecza / sequentialCallback.js

Last active November 20, 2016 06:38

	function sequentialCallback (...fns) {
	return (...args) => {
	const done = args.pop()
	const next = (error, ...args) => {
	if (error) return done(error)
	if (fns.length) {
	const fn = fns.shift()
	return fn(...args, next)
	}
	return done(null, ...args)

zspecza / multiple-values.js

Last active November 16, 2016 19:45

	const validateTransformation = sequentialCallback(
	transformSomething,
	validateTransformed,
	(validated, callback) => callback(null, validated, 'data is valid:')
	)

	validateTransformation({ foo: 'bar' }, (error, validated, label) => {
	if (error) {
	console.error(new Error(error))
	} else {

zspecza / passing-data.js

Created November 16, 2016 12:54

	const validateTransformation = sequentialCallback(
	transformSomething,
	validateSomething
	)

	const something = { foo: 'bar' }

	validateTransformation(something, (error, validated) => {
	if (error) {
	console.error(new Error(error))

zspecza / sequential-callbacks.js

Last active November 16, 2016 15:34

	const getValidatedTransformation = sequentialCallback(
	findSomething,
	transformSomething,
	validateTransformed
	)

	getValidatedTransformation((error, validated) => {
	if (error) {
	console.error(new Error(error))
	} else {

zspecza / point-free-promise.js

Created November 16, 2016 11:44

	findSomething()
	.then(transformSomething)
	.then(validateTransformed)
	.then((validated) => console.log('data is valid:', validated))
	.catch((error) => console.error(new Error(error))

zspecza / promise-heaven.js

Created November 16, 2016 11:40

	findSomething()
	.then((something) => transformSomething(something))
	.then((transformed) => validateTransformed(transformed))
	.then((validated) => console.log('data is valid:', validated)
	.catch((error) => console.error(new Error(error))

zspecza / callback-hell.js

Created November 16, 2016 11:35

	findSomething((error, something) => {
	if (error) {
	throw new Error(error)
	}
	transformSomething(something, (error, transformed) => {
	if (error) {
	throw new Error(error)
	}
	validateTransformed(transformed, (error, validated) => {
	if (error) {

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