Elm vs Dart

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.

Dart is a single threaded programming language. So if any piece of code blocks the execution of the program, the program practically freezes. To avoid this Dart makes use of asynchronous operations which let your program run without getting blocked. This is done through Future objects.

A Future is an object which represent a means for getting a value at a certain point in the future. A function may invoke a Future and when that happens, two outcomes can be achieved:

1. The function is unable to return a value, so it queues up work to be done and returns an uncompleted Future object.
2. Or later when a value is available to be returned, the Future object completes with that value.

Dart includes a truly comprehensive core library, making it unnecessary to include disparate, external resources for basic functionalities Other than reducing the need to pull in various 3rd-party utilities this also ensures that all Dart code looks and feels the same.

Out of the box, the developer gets core libraries to help with: async, collections, strings, regexps, conversions, formats, file I/O, math, typed data, and more.

Dartium (Chromium derivative) is a browser with integrated Dart VM, which allows you to run and debug native Dart code during development for short edit-reload cycles. Only for testing on other browsers and deployment is transpiling to JS necessary.

Dart has a lot of tools available which help with developing Dart applications. Some examples of those tools include:

• pub - package and dependency management and build tool
• analyzer - static syntax analysis with linter, quick fixes, autocompletion support for easy IDE integration
• test - powerful and flexible testing framework and test runner
• dev_compiler - generate reusable JS instead of tree-shaken minified JS output (work in progress)
• dartfmt_ - source code formatter
• server-side VM
• observatory - a powerful tool for profiling and debugging running Dart code (for Dartium and Dart server code)

In Dart many browser differences (subtle differences and also missing features) are abstracted away or polyfilled. When Dart is transpiled to JS the output works on all supported browsers. There is usually no need to load polyfills or to consider browser differences during development. No need for libraries like jQuery to make the same code work the same on all browsers.

The language will look familiar to Java developers, easing the learning curve.

And yet, while it's similar, it has some nice syntax facilities to avoid common boilerplate code found in Java. Code is terser, yet readable.

Dart has an optional type system which makes Dart a great language for prototyping. It encourages developers to gradually evolve their programs without worrying about types first.

Dart was designed to be as expressive as possible. Ahead-of-time compilers can compile Dart code to efficient machine code. This is especially important when deploying to mobile where you don't want (or can't) use a JIT.

Strong mode applies a more restrictive type system to Dart to address its unsound, surprising behavior in certain cases.

Generators, also known as semicoroutines, are also a generalization of subroutines.
Generators are primarily used to simplify the control of iteration behavior of a loop, the yield statement in a generator passes a value back to a parent routine.

A generator is very similar to a function that returns an array, in that a generator has a certain number of values. But instead of building and returning an array that contains all the wanted values, a generator returns them one at a time, this saves memory and allows the caller function to start processing the first few values immediately.

Dart to Javascript compiler (dart2js) generates very high quality source code with very high optimization. The output code is also very readable and easy to understand.

Dart does not just compile to JavaScript, it also compiles to native code on mobile platforms like iOS and Android as demonstrated by flutter.io