When comparing LiveScript vs PureScript, the Slant community recommends PureScript for most people. In the question“What are the best (productivity-enhancing, well-designed, and concise, rather than just popular or time-tested) programming languages?” PureScript is ranked 45th while LiveScript is ranked 67th. The most important reason people chose PureScript is:
Has Typeclasses and RankNTypes
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Designed for High-level functional code
LiveScript has terse syntax for common functional operations like map, and ships with a library, prelude.ls, with many of the functions most commonly used by functional programmers.
Pro Good amount of programmer flexibility
There's a huge range of features that can make common tasks faster.
Pro ECMA 6 Features
It is the declared goal of LiveScript’s creators to track ECMAScript 6. Hence, the language gives you ECMAScript 6 plus type annotations (which are optional).
LiveScript's module syntax is currently a bit behind the ECMAScript 6 specification (something that will be fixed eventually). It supports two module standards: CJS (Node.js) and AMD (RequireJS).
Pro Fixes coffeescript scoping issues
=
is used to declare variables in the current scope, in order to redeclare variables of outer scope :=
is used. This way bugs are reduced.
Pro Supported by WebStorm and Visual Studio
Pro Higher kinded types
Has Typeclasses and RankNTypes
Pro High performance FFI code
The Eff monad, which is used for FFI code, optimizes out calls to bind, and supports tail call optimization, resulting in clean, efficient Javascript. The psc compiler also specifically recognizes the ST monad, and transforms scoped variables into mutable Javascript variables, for even more efficient code.
Pro Type safety
Compiling should be your first unit test. A tight type system (static and hopefully strong) will catch many logic errors that are often difficult to spot through debugging. In languages like PureScript, if it compiles, it often runs properly.
Pro Pure functional language
You cannot have side effects, unless a function is explicitly defined as so.
Pro Modules can be compiled to CommonJS
Modules compiled to CommonJS can be included with 'require', making it incredibly simple to call Purescript code from Javascript.
Pro Has row polymorphism and extensible effects
Pro FFI
FFI system is quite good and easy to use. You can import functions curried or not curried. Records and arrays use native JS objects and arrays.
Pro Thorough documentation
The Purescript website has fairly thorough documentation for all of the language's features, and the Purescript blog contains several examples of practical usage.
Pro Awesome web frameworks
Thermite (React)
Halogen (VDOM, similar to ELM)
And hit these up with Signals, Isolated/(Managed?) Components, powerful functions and FFI
Cons
Con Strong functional lean
LiveScript is designed to be a high level functional language. For people who prefer a more imperative approach it can be hard to get used to.
Con Compiles to unreadable javascript
JSON.stringify(
each(upCaseName)(
sortBy(function(it){
return it.id;
})(
(function(){
var i$, ref$, len$, ref1$, j$, len1$, ref2$, results$ = [];
for (i$ = 0, len$ = (ref$ = table1).length; i$ < len$; ++i$) {
ref1$ = ref$[i$], id1 = ref1$.id, name = ref1$.name;
for (j$ = 0, len1$ = (ref1$ = table2).length; j$ < len1$; ++j$) {
ref2$ = ref1$[j$], id2 = ref2$.id, age = ref2$.age;
if (id1 === id2) {
results$.push({
id: id1,
name: name,
age: age
});
}
}
}
return results$;
}()))));
Con Lots of dependencies needed to get started
Purescript is written in Haskell, but meant to be used with Node.js. As a result, to get started , users must install ghc, cabal, node.js, grunt, and bower. Purescript also has its own compiler, and different semantics form Haskell, and so even after installing, there's still some overhead to getting productive with Purescript.
Con Lack of good IDE/tooling support
Con Documentation not updated
Con Ecosystem not stable
Con Restrictive FFI
Functions exported are all curried, and must be called as such from Javascript. The FFI syntax for importing Javascript functions, while slightly simpler and more readable than UHC/Fay's, means that calls to methods on objects must be wrapped to pass the object explicitly as a parameter.
Con Slow compilation
On large project, for example Halogen