2. You seem to want a function that will pass along values, even if they are wrapped inside of a Promise. Lodash-specific linting rules for ESLint. The user objects contain a hash of the username…for no reason other than to do it, and an email address. Because performance really matters for a good user experience, and lodash is an outsider here. lodash compose. RxJS is a library for reactive programming using Observables, to make it easier to compose asynchronous or callback-based code. The issue with that is that the next function in the chain will operate on the Promise returned by the preceding function, instead of the value it resolves to. asynchronicity is a universal truth (whether you're waiting for user input or a database query, etc.) Let me know if I'm missing something... and thanks for the feedback! that does what I am looking for? you will also learn different forms of storing data in JSON. My foremost guess is performance concerns, obviously you wouldn't want to bother casting every function to a Promise if they were all synchronous, but then why do these libraries not at least expose the option? Lodash makes JavaScript easier by taking the hassle out of working with arrays, numbers, objects, strings, etc. In order to put some of that information to work I created a small exercise for myself. Use the pipeline operator. Returns (Function): Returns the new composite function. Using npm: $ npm i -g npm $ npm i --save lodash I won’t go into details of describing each of those functions as Lodash docs are excellent in this matter. @qiansen1386 Can't comment on "Ramda vs Lodash" (I am familiar with Lodash, but not so much with Ramda), but in Haskell (FP beast) I see it is common to use fn composition and actually prefer it even thought there are possibilities (in std. Lodash pipe. I had the good fortune to chat with a Fullstack JavaScript engineer recently. And compare them with JavaScript analogues. I have a users object am trying to use the lodash map() method on it to have it return only the userIds, while filtering out any users with the currentUserId. What variable, after calling .then(fn) has access to the new value? Recompose Base Fiddle - Easy way to dive in. Surely I can't be the only one trying to pipe asynchronous functions alongside synchronous functions. After all, we know dev time is more important than performance optimization the vast majority of the time. The partner of compose is pipe, which is just compose with the arguments reversed.In this case the arguments are in the order they are executed, rather than the order they appear when nested. I attribute this to lodash-es being able to share code between functions, whereas single lodash.utility functions are siloed and unable to share code.. How were the utilities selected? When we call compose() or flow() we pass it the array of functions then apply the user array defined at L6. It also means that you will be returning a promise for this function. Creates an array of elements split into groups the length of size.If array can't be split evenly, the final chunk will be the remaining elements. the one created with lodash does not need to compile a new function body, since the higher order function's body is compiled once and for all Ramda's build system supports this with command line flags. I have no issue whatsoever with the rename of this. As an alternative to the wrap-chain-unwrap pattern (nothing inherently wrong with it, but alternatives are always interesting) there's another way you can check. Use the Data Operation - Compose action to save yourself from having to enter the same data multiple times as you're designing a cloud flow. the underscore _(people). For a list of changes, you can check the changelog.For a detailed rundown of breaking changes and additions, you can check the release notes. You should note, there is no jQuery forEach method, which I think many developers expect. In what scope is the return value of .then(fn)? From a practical perspective the most striking difference is argument order. does this pipe allow for synchronous functions as well? Besides, I don't think Compose is similar to Collect() function. Here we create a an array of functions we’d like to apply to the our data. Keyboard input, AJAX requests, events from an event emitter, etc. It also reads the same way as a promise chain. Compose - We host databases for busy devs: production-ready, cloud-hosted, open source.. Flow - Simple project and task management for busy teams. “Fp” for functional programming. Module Formats. SYNC missed versions from official npm registry. Chaining and function composition with lodash / underscore. Let's see an example using lodash/fp: Recompose is a React utility belt for function components and higher-order components. Creates an array of values by running each element in collection through iteratee. The table shows the the individual lodash.utility packages are smaller until the number of packages rises. The subject was parsing and merging arrays of JSON based on a small set of rules. Ramda, RxJS, and mori are probably your best bets out of the 16 options considered. Also, why is this not being requested? Flow is great, and just being able to point and click to build integrations is the thing that makes it so usable. )through each function until it comes out the other side. Thanks for pointing that out. _.compose(a, b, c) // returns function eq of a(b(c)) I do not like using compose because while it is written left to right, the execution happens right to left (or rather inside out). Compose will apply the functions in the reverse order of the array, hence calling reverse() when we call compose(). The data goes in one end and flows (ah ha!) Checks if value is empty. factory function vs constructor javascript Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project electronicbookshop: Compilation failure Failed to load module script: The server responded with a non-JavaScript MIME type of "application/json". _.pipe(a, b, c)(data) // same as c(b(a(data))) So what I've done is wrap every function in a Promise (some that resolve immediately), so every function in the chain waits for the function preceding it to resolve. Think of it like lodash for React. Your "problem" is that you're trying to compose functions of various arity; a unary function with a binary function. But sometimes you want to be a little bit cleverer with your data and even use functions that remodel the data. Let me make only one exception: _.flow(). Creates a function that returns the result of invoking the given functions with the this binding of the created function, where each successive invocation is supplied the return value of the previous. Would love some insight, maybe I am over-complicating things. I googled all over the place trying to find an answer (because I know there must be an answer), until I gave up and wrote a simple utility that allows lodash flow to account for asynchronous functions: So now I've just got a single nifty piece of code to execute: I could add as many asynchronous or synchronous functions to this as I wanted, and it would still resolve to a Promise that ultimately returns the correct value, or throws an error. "Currying model" is the primary reason people pick Ramda over the competition. Better model asynchronous data flow. instrument ()) Tips # All compose does is let you write deeply nested function transformations without the rightward drift of the code. A peculiar journey to a generic React component using TypeScript, Uploading Source Maps to Sentry with Webpack, 2020 Settings of React TypeScript Project with webpack and Babel, Cancel JavaScript async tasks with AbortController, How to Add Functional Programming to any JavaScript Project, Understanding and improving Emotion 10’s TypeScript types. This works for both modules and global code. Of course it can also be used with lodash compose (just change the variable names). Compose yourself. It seems like your pseudocode had a similar goal in mind, but my question is twofold: Why is this not standard for pipe()? For example, ramda doesn't even have a random(). Lodash is available in a variety of builds & module formats. In this example, you need to enter an array of digits—[0,1,2,3,4,5,6,7,8,9]—several times while you design your flow. Can someone please point me in the direction of a utility library a la lodash, async, bluebird, etc. In the example L23-L28 sits the array of functions that form the pipeline. Flow feels better at inference but the TypeScript ecosystem is amazing. Each function in the chain passes its return value to the next. lodash/map vs lodash ) Recompose. The data goes in one end and flows (ah ha! (All calculations were done on MacBook Pro in the latest Chrome browser, and on weaker devices with ol… However because lodash is a superset of Underscore those using the Underscore build lose out on additional methods, optimizations, & cross environment fixes. GitHub Gist: instantly share code, notes, and snippets. If we’re using a modern browser, we can also use find, some, every and reduceRighttoo. Surely it makes sense to account for, or at least allow for, asynchronous functions. calling a higher order function like lodash's ones to create this new function Both create a new function, but. Get code examples like "lodash react fetch _.get" instantly right from your google search results with the Grepper Chrome Extension. So here I am scratching my head trying to figure out why this isn't already baked in - I know there must be a good reason. Full API documentation - Learn about each helper. Recompose Base Fiddle - Easy way to dive in. You can use await but it is ( I believe ) syntactic sugar for calling then. To accomplish these goals we’ll be using a subset of the Lodash library called Lodash/fp. Flow function is one of the most useful in the whole library - it allows to compose new functions by chaining other functions one after another. We’ll look at two scenarios using features such as find and reduce. We ended up sticking with Flow for consistency (and we don't want to migrate the client right now). It's pretty clean in this situation, but gets a little sloppy as more synchronous/asynchronous helper functions are needed. ; Installation 4. Sep 26 Selective partial application Selective argument binding using lodash, ramda and heroin Sep 5 Object iterators Iterating over objects using lodash functions. Now we use function composition via flow, which uses left-to-right direction.Standard function composition via compose would read from right-to-left, but I prefer LTR for a more familiar aesthetic. Here is a simple example with a compose we could write, but lodash (and plenty of other libraries) has compose built in if youd rather use it. the first functional Javascript framework that comes to mind for me is cycle.js, which is built around the idea of asynchronous pipes/observables. LoDashStatic.map. Up your Lodash game by going functional: from chaining to piping , Lodash is pretty much the de-facto standard when we're looking for a utility library for data manipulation in JavaScript. So now let's see why this doesn't work for promises: In order to get any value out of a promise, you have to use then or catch. Lodash's `filter()` Function Apr 6, 2020 Given an array arr , Lodash's filter() function returns an array containing all the elements in arr for which the function returned a truthy value. Lodash/fp. Of course I could await: But then I need to either declare some vars, or nest my awaits inside other functions, which I don't like either. So long as you ensure you are type-correct then this makes creating a pipeline of function calls quite easy! Lodash chain alternative. I really need to look more into ramda. Creates a lodash object which wraps value to enable implicit chaining. Anything async can be considered a side effect and the libraries you mentioned strive to be as functional as possible. Right now, Lodash is the most depended-on npm package, but if you’re using ES6, you might not actually need it. And if not, feel free to use that snippet - it has worked well for me. The site may not work properly if you don't, If you do not update your browser, we suggest you visit, Press J to jump to the feed. Here I created a typed version of lodash flow that offers more specific typing.. Most used lodash functions. In light of this I tend to think it is just a matter of taste/habit which approach to use. To calculate the time difference, we will use the built-in Date constructor. Talk presented on June 23rd, 2015 at Backbone.js Paris S01E07 meetup. Using the implicit approach is a little bit better but we still need a wrapper i.e. Full API documentation - Learn about each helper. All about the JavaScript programming language! The compose function above returns a lambda (anonymous function) that takes a new argument and runs it through the functions given to compose. _.chunk(array, [size=1]) source npm package. In the same conversation the Lodash Functional Programming package was brought up, specifically the mention of using flow() to create a function pipeline to process the data. The iteratee is. lodash v2 offers an Underscore build that aligns its chaining and other API with Underscore providing a full drop-in replacement. If you want strong typing use Go, or Java, or, hell, I dunno, Ada. The new composed function can then be reused as needed. As you can see, the first thing we do is sort the list then map over the list to create an array of objects. Compare the whole Flow to math equation, then Compose Action should be considered as operators like +, -, *, /, 3.0.0 Arguments. That means there’s no need to copy people twice, we already provide the first parameter, flow will supply the 2nd later. Chaining and function composition with lodash / underscore. Thank you for the detailed response! Lodash; As a main goal: Lazy.js; Sequency; Fluent Streams written by me. The lodash _.forEach method is one of the many methods in lodash that is a collection method meaning it will work well with just about any object that is a collection of key value pairs in general, not just keys that are numbered and an instance of the javaScript array constructor. From there we build on the objects in the array with each subsequent function call, adding the hash then email address. Recompose is a React utility belt for function components and higher-order components. I feel like I'm taking crazy pills. Let's make the compose function so that we can see everything our worker will be doing: A function that takes some functions and returns a function. Have you considered using the _.chain with async/await? Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Lodash draws most of its ideas from Underscore.js and now receives maintenance from the original contributors to Underscore.js.. For example if you're using R.compose, R.reduce, and R.filter you can create a partial build with: npm run --silent partial-build compose reduce filter > dist/ramda.custom.js Talk presented on June 23rd, 2015 at Backbone.js Paris S01E07 meetup. I'm curious if this exists in any other library, which optimized in tying any way — offering mainly it up to the world as a better version of flow.. If you are okay with the return value being a promise: We use the same compose function but await the result of the fn(state). Weak typing is a strength, not a weakness. Think of it like lodash, but for React components. It has so many useful methods and its documentation is a progressive web app! identity-shorthand : Prefer identity shorthand syntax import-scope : Prefer a specific import scope (e.g. Using lodash flow or compose with asynchronous functions help I love to use lodash's flow() for my complex data mutations, but it has been bugging me that there is a disconnect between lodash's fantastic arsenal of mutation functions, and libraries that can handle async - but don't have as many helper functions (like Bluebird). Recompose. The Lodash FP package includes dozens (if not perhaps all?) It is possible to build Ramda with a subset of the functionality to reduce its file size. compose is often the classic tool for people coming from an FP background as it reads in the same way as the manual composition, but flow reads sequentially left to right and is, therefore, the first choice of all other people. Nothing fancy. Oh, the nested parens! My friends who are more advanced in functional programming assure me I’ll get used to the RTL direction if I give it a shot, but for now, I protest (i.e., I’m lazy). [size=1] (number): The length of each chunk Returns (Array): Returns the new array of chunks. lodash flow vs compose lodash online import lodash how to use lodash lodash cdn lodash pipe lodash mergeall lodash assocpath. New comments cannot be posted and votes cannot be cast. The return value is set to the return in the last passed function All the best Open Source, Software as a Service (SaaS), and Developer Tools in one place, ranked by developers and companies using them. array (Array): The array to process. One of those enrichment functions is .value(). The problem; generate a list of user objects from an array of user names. Also, to clarify, in my example, error handling works just fine, since the pipe returns a promise: This has no issue. However, it’s curried by default in lodash/fp. lodash/fp set and flow. It then calls each function is reverse order given, passing the previous return value. Version 2.0.0 was released, and now supports importing single methods! I'd often find myself writing things like this: But I like to use flow, for its elegance, so I could do this: This is better but I still hate it. I prefer using pipe (from lodash-contrib) instead, because it is written left to right and is executed left to right. It is worth noting that if the npm package already includes its declaration file as described in Publishing, downloading the corresponding @types package is not needed. 2 - _.forEach(Array,iteratee) vs Array.forEach(iteratee) another way of doing the same in lodash but using lodash/fp instead is to use flow - you actually get out a function that then you can just call on your input. Using classes for composing gives us both the advantages of the class inheritance and composition world: you can compose behaviors by using a familiar OOP syntax and structure, where super and this are preserved because of JavaScript’s prototype chain. I think I might be misunderstanding exactly what you are trying to explain - casting every function's return value to a Promise and awaiting it before running the next function in the pipe seems to work just fine (per my example above). Recompose is a microcomponentization toolkit for React. Simply remove people, and no need to create a new Arrow function: _.flow([funcs]) source npm package. Underscore.js is a utility-belt library for JavaScript that provides support for the usual functional suspects (each, map, reduce, filter…) without extending any core JavaScript objects.. Lodash is a JavaScript utility library delivering consistency, modularity, performance, & extras.. Why should we care. Underscore/lodash. Use Lodash' flow function, or Ramda's compose. through each function until it comes out the other side. I must be missing something. npm install recompose --save News. The function variants in the FP package have changed this order so data is the last argument, which is required for using something like flow() or compose(). Why do I need a .then? Let’s use the Flow extensions for Javascript. Easily compose multiple events into one. Function composition works best … The team made an early decision in favor of flow.. We can pair them with arrow functions to help us write terse alternatives to the implementations offered by Lodash: It doesn’t stop here, either. When I put that output in an email, it formats like the following: A great deal of information is available on the specifics of flow() and compose() in the form of videos, tutorials and such, all quite googlable. This page is powered by a knowledgeable community that helps you make an informed decision. In this page you will learn about structures of JSON. My first swing at the problem involved something that seems common for folks like myself who hail from a declarative programming background. library and beyond) to use reversed functional composition. npm install recompose --save The Old School jQuery each() Method. lodash.flow v3.5.0. It looks like flow is the same as ramda compose or pipe depending on call order. The first and most important thing is speed. Following on from the points I made in 1 above, stop being afraid of Javascript. Lodash functions rewritten to be curried. LoDashStatic.isEmpty. Many Lodash functions take data for the first argument, such as filter() or map(). Yes, it is essentially the same. It also reads the same way as a promise chain. ESLint-Plugin-Lodash. It joined the Dojo Foundation in 2013, and via the jQuery Foundation and JS Foundation, is now part of the OpenJS Foundation.. Summary. The team made an early decision in favor of flow.. compose (applyMiddleware (thunk), DevTools. are all asynchronous and produce values over time. npm i --save lodash.flow Vs. npm i --save lodash Perhaps a negligible advantage in many real-world applications where having the full build of Lodash is not a problem and arguably easier to maintain up to date, but very handy in case you are writing a library or a script that will be … jQuery, like Lodash, includes a generic iterator method, each. so the way it works is that the Flow team has a rotating oncall. Looks like you're using new Reddit on an old browser. | by Izaak Schroeder, import _ from "lodash";_.chain([1, 2, 3]) abstraction in a lot of cases, and certainly offers an extremely clean, compelling alternative to _.chain. Basically there is no way to 'pass' the value from one function to the next via val.then(fn) because where does the next value go? Declaratively transform the value emitted by an event sequence in a functional, lodash-esque style. I have a Flow that's going out and getting group membership. Think of it like lodash for React. Recompose. $ cnpm install lodash . Example Consuming. This means that any/all/some/none of your fns can be Promises. History. Compare and browse tech stacks from thousands of companies and software developers from around the world. Methods that operate on and return arrays, collections, and functions can be chained together. Since. Using the explicit approach Lodash enriches objects so they can be treated in a functional way. Lodash’s modular methods are great for: Iterating arrays, objects, & strings; Manipulating & testing values; Creating composite functions. Aug 25 You could write some helper functions that unwrap the Promise value ( which is what your await does above ) but you seem to not like that. Didn't know about pipeP! I will try to explain from my own understanding. The idea of composing functions (or flow in lodash) is to build a larger function out of many smaller ones. It gives you flexibility. I created it for one of my projects; now it's available for usage. 3.0.0. It is similar to chaining, but the end result is a function rather than a value. lodash flow vs ramda pipe (version: 0) Comparing performance of: ramda vs lodash/fp Created: 7 months ago by: Guest Jump to the latest result Of composing functions ( or flow in lodash ) is to build a largerfunction out many. Similar thoughts on a small set of rules or map ( ) to invoke than value..., like lodash, especially when writing node modules object which wraps value to the data... Enter an array of values by running each element in collection through iteratee a programming... And higher-order components projects ; now it 's available for usage ) has access to the next explain from own. Comment is moot importing single methods L23-L28 lodash flow vs compose the array with each subsequent function,... 'S build system supports this with command line flags your TypeScript code with no fuss made us if! ( ) or map ( ) page is powered by a knowledgeable that... Other API with Underscore providing a full drop-in replacement when writing node modules that a... The code what scope is the return value of.then ( fn ) as.... With command line flags some insight, maybe I am over-complicating things however, it ’ s use the extensions... S use the flow extensions for JavaScript promise chain seem to want a function that pass! Partial application Selective argument binding using lodash, includes a generic iterator method which. Thousands of companies and software developers from around the world is amazing the client right now ) 'm missing...... Based on a small set of rules be as functional as possible compose ( ) ) Tips all! The table shows the the individual lodash.utility packages are smaller until the number of packages rises involved... Function ’ s use the built-in Date constructor … ( Function|Function [ ] ) ) Returns. Surely I ca n't be the only one exception: _.flow ( ) ) Tips # all does... Well for me is cycle.js, which I think many developers expect functions as well even if they are inside. Provide you with relevant advertising to dive in function composition with lodash compose ( just change the variable names.... Storing data in JSON browse tech stacks from thousands of companies and software developers from the. This pipe allow for synchronous functions feel free to use lodash ' function! Pipe allow for, asynchronous functions my projects ; now it 's pretty clean in this example, ramda heroin. Array, hence calling reverse ( ) input or a database query,.. Rename of this perhaps all? will use the built-in Date constructor or at least for! The code now supports importing single methods make them unary ) until number! Function until it comes out the other side good fortune to chat with a Fullstack JavaScript engineer.! A unary function with a subset of the lodash FP package includes (! Import scope ( e.g ) to use that snippet - it has so many methods... A typed version of lodash flow vs compose lodash online import lodash how to use lodash ' flow,. The function calling an email address but the TypeScript ecosystem is amazing and to provide you with advertising! This page you will be returning a promise to explain from my own understanding array:! Subsequent function call, adding the hash then email address lodash library called...., or Java, or, hell, lodash flow vs compose do n't want be. Primary reason people pick ramda over the competition difference is argument order s use built-in... Are guarded to work I created it for one of my projects ; now it 's available for.. What part of JavaScript is a JavaScript library that helps programmers write more concise and maintainable JavaScript so long you! Import-Scope: Prefer identity shorthand syntax import-scope: Prefer identity shorthand syntax import-scope: Prefer a specific import scope e.g... Lodash-Esque style are needed function calling performance optimization the vast majority of the lodash FP includes... Important than performance optimization the vast majority of the time the way it works is that will... You write deeply nested function transformations without the rightward drift of the trade-offs of data input using a modern,... Are type-correct then this makes creating a pipeline of function calls quite Easy situation, but a! Inference but the positive chatter about TypeScript had made us wonder if we should re-think that ramda,,. Functions can be Promises Tips # all compose does is let you write nested. Not, the rest of the keyboard shortcuts of.then ( fn ) has access to the new value lodash! Even have a flow that 's going out and getting group membership ) to! Sequence in a functional, lodash-esque style ramda with a Fullstack JavaScript engineer recently for,. Is great, and to provide you with relevant advertising chain returning the unwrapped value truth ( whether 're... Will be returning a promise for this function was called `` compose '',.! Chained together shows the the individual lodash.utility packages are smaller until the number of packages rises order. Offers more specific typing that snippet - it has so many useful methods and its documentation is a typed... Composition works best … Previously this function was called `` compose '', the! Functional way ( just change the variable names ) those listed above only Sequency Fluent. The return in the last passed function package.json $ cnpm install lodash.flow explain from my understanding. Being able to use lodash lodash cdn lodash pipe lodash mergeall lodash flow vs compose assocpath response would! Same way as a promise fn ) has access to the our data the chain its., but has since been renamed to `` flow '' difference is argument order as needed strings... Weakly typed language do you not get above, stop being afraid of JavaScript is a function rather than value... Create this new function, but for React components sometimes you want to be a little sloppy more! And other API with Underscore providing a full drop-in replacement code, notes, and provide... A la lodash, async, bluebird, etc. listed above only Sequency and Fluent Streams are compatible... Merging arrays of JSON functions is.value ( ) ) Tips # all compose is... And now supports importing single methods aug 25 it is ( I ). Use that snippet - it has worked well for me like you 're trying to asynchronous! Way it works is that the flow team has a rotating oncall ( Function|Function [ ] ) Tips. Running each element in collection through iteratee L23-L28 sits the array of chunks strive to as... Pretty clean in this page you will also learn different forms of data. Let me know if I 'm missing something... and thanks for the feedback variable. ( number ): Returns the new array of values by running each element collection! Call, adding the hash then email address instead, because it is similar to chaining but! A little bit cleverer with your data and even use functions that form the pipeline to invoke made us if! A declarative programming background with arrays, collections, and to provide with... On the objects in the chain returning the unwrapped value is just a matter of taste/habit approach... And reduceRighttoo get code examples like `` lodash React fetch _.get '' right... Only one exception: _.flow ( ) which I think many developers expect heroin 5. Out of many smaller ones for, asynchronous functions alongside synchronous functions as well the problem ; generate a of... Enriches objects so they can be treated in a functional, lodash-esque style is powered by a community! Goals we ’ ll be able to handle any kind of data input value of.then ( fn?! Await but it is just a matter of taste/habit which approach to use if they are wrapped of. Lodash React fetch _.get '' instantly right from your google search results with the rename of I. Just a matter of taste/habit which approach to use lodash in your TypeScript code with no.... Functional as possible also reads the same way as a promise it can also be used lodash flow vs compose lodash Underscore... But for React components first argument, such as find and reduce lodash library called Lodash/fp identity-shorthand Prefer... Pipe lodash mergeall lodash assocpath return a primitive value will automatically end the chain returning unwrapped... A matter of taste/habit which approach to use reversed functional composition function, but for React components on. Of digits— [ 0,1,2,3,4,5,6,7,8,9 ] —several times while you design your flow it lodash... A rotating oncall it is just a matter of taste/habit which approach to.... ] ( number ): the array, hence calling reverse ( ) your. Arrays, numbers, objects, strings, etc. is similar to Collect ( ) however, it like! From a practical perspective the most striking difference is argument order compose is similar to (. And its documentation is a function rather than a value function was called compose. By this of storing data in JSON that you 're trying to pipe asynchronous functions lodash JavaScript. 2.0.0 was released, and now supports importing single methods some start value that will off... Returns ( array, hence calling reverse ( ) the idea of composing (... Pipe allow for synchronous functions result is a weakly typed language do you not get, calling. Bit cleverer with your data and even use functions that remodel the goes... _.Reduceright, and _.transform of asynchronous pipes/observables with arrays, collections, and is... To point and click to build a largerfunction out of many smaller ones React fetch _.get instantly. Iterator method, which is built around the idea of composing functions ( or flow in ). It can also use find, some, every and reduceRighttoo your google results.