Elm vs Reason ML

Lack of run-time exceptions makes it easy to produce large swathes of reliable front-end code without drowning in tests.

ML static typing is great because it's always there, you just choose how explicit you want to be and how much you want the compiler to do.

In no other language you can refactor so easy without any worries, since the compiler will guide you through. It is like TDD but than compiler-error driven.

As Elm was designed as a front-end langauge, it has out of the box support for things like DOM-element creation, letting programmers focus on their application logic, rather than implementation details specific to the web.

You can try to apply some functional programming ideas in other languages that have an imperative basis, but you haven't seen the real power unless you tried it in the environment of purely functional programming. Elm is a simple language with great learning resources and easy graphical output, which makes it easy to explore the power of functional programming. Plus programming in Elm is very readable.

All major editors have great support. With Atom for example, Elm plugins are available for linting, formatting, make/compiler support and Elmjutsu will simply overflow you with super useful functions, like navigate to referenced definition and show expression type.

The Elm Architecture means you don't need to spend valuable time and effort choosing the right frameworks, state management libraries, or build tooling. It's all built in.

Elm uses easy to use modules.

Use:

import List
import List as L
import List exposing (..)
import List exposing ( map, foldl )
import Maybe exposing ( Maybe )
import Maybe exposing ( Maybe(..) )
import Maybe exposing ( Maybe(Just) )

Creation:

module MyModule exposing (foo, bar)

Easy to learn, most functions have only one way, not 5 alternatives where you must study where to best use what.

Support for hot swapping and interactive programming is included.

The lack of side-effects and simple, consistent language semantics make it easy to quickly review incoming changes.

Pure functions, immutable data structures, amazing compiler, clean and homologous syntax used for HTML, logic, and optionally to replace CSS, elimination of entire classes of bugs so you don't even need most unit tests. These factors lead to better code, better programs, higher confidence, and ultimately, more satisfaction.

Luckily you do not have to learn Haskell to be able to do any Elm. It is meant to be a language that compiles to Javascript, so for Javascript programmers (Front end) not for CS students who want to learn as many different algorithms as possible.

Ocaml type inference is so smart that you never have to repeat yourself and keep code very clean, type errors also are very pleasant.

Despite being a completely different language Javascript programmer will find that the syntax of ReasonML has many familiarities with Javascript.

unlike other js-targetting languages that are thought as a way to have a language that pleases community X run in a browser, reason is really designed with JavaScript community in mind. it removes the bad parts but keeps its syntax and its best design principles (from Scheme): simplicity, minimalism, and functions as building block.

reason includes true immutability, but it has escape hatches to let you use mutations in exceptional cases.

The same reasonml code can compile to js (eg. run on browsers or node.js, use any lib in npm), or compile to assembly thru ocaml (unless of course you load js externals), running on any device, with C-comparable (or better) performance.

Reason was created by the creator of react, for developers already using JSX to template web or native UIs this results very familiar.