monadicjs

Monad library for JavaScript

Monads can be very useful for async IO. They succefully appeared in Haskell. Haskell provides the do notation for executing monads. And this library ports do to JavaScript. Something that looks like this in Haskell

  do {
    fileContent <- readFile "README.md"
    putStr fileContent
  }

will look like this in JavaScript:

  const fs = require("fs")
  do_(function*() {
    const fileContent = yield fs.readFile.bind(null, "README.md")
    console.log(fileContent)
  })

Checkout tests how to experiment with it.

You will not be able to code every monad that one can programm in Haskell (like the list monad), but a lot is possible with this approach. Here is what you can do in Haskell but not with this library:

  do {
    x <- [1,2,3]
    return (2*x)
  } {- [2,4,6] -}

Available monads

• Maybe Haskell Maybe
• Either
• Promise
• NodeContinuation or node callbacks
• State Monad)

Ideas

• use a (kind of) state monad for react-redux store
• monad transformers
• react-redux store middleware