When comparing Cor vs Idris, the Slant community recommends Idris for most people. In the question“What are the best languages that compile to JavaScript? ” Idris is ranked 23rd while Cor is ranked 42nd. The most important reason people chose Idris is:
Idris not only has support for type classes, but is a fully dependently typed language, giving you the full power to statically verify your code.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Easy to debug
Cor supports source-maps, allowing you the easy debugging in major browsers. However a line of Cor source is compiled to the exact line number in JavaScript for accurated debugging when developing in platforms that doesn't supports source-maps such as servers.
Pro Clean syntax
Cor enables you to write large applications by providing a clean syntax, classes and a modular architecture to keep organized code, enforcing the writing of readable source code based on conventions.
Pro Cross platform
Cor compiles to plain JavaScript, so, to run it in Node.js or in the browser is piece of cake.
Pro Support coroutines
Cor support coroutines which can be chained, stopped, and synchronized, fitting very well into the web asynchronous world.
Pro Hot reload
Cor provides a smooth front-end development by furnishing a builtin hot-loader which resolves dependences and compiles source code on the fly, with just reloading the Web page. You will only need to use CLI tools to deliver a production-ready version of the app.
Pro Concurrent and parallel
Cor allows to synchronize coroutines by passing messages through channels, and supports the execution of many tasks in parallel, all of that by writing sequential code.
Pro Full dependent types
Idris not only has support for type classes, but is a fully dependently typed language, giving you the full power to statically verify your code.
Pro Domain driven design and type driven development
Because of full dependent types in Idris, the programmer can focus more on modelling the domain with types and waste less time fixing common bugs that the type checker will catch. Dependent types help apply type driven development and a lot of code auto generation, making the compiler and type checker an ally in developing working software instead of just getting in the way.
Cons
Con Work in progress
Cor is still a very much young project (as of November 2015) with just one contributor, few stars on GitHub and virtually no learning resources outside the official documentation.
Con Not widely used
Con Not widely used
Con Weaker type inference
As type inference is undecidable for dependently-typed languages, Idris cannot offer the full type inference that Haskell supports, and so more type annotations will be needed.
Con Different semantics from Haskell
Idris, while similar to Haskell, has strict semantics, which may cause some confusion if your backend is done in Haskell. If using Idris, it would make sense to do the backend in Idris as well, if not for the fact that Idris currently has fewer libraries available for web development than Haskell.
