jivagoalves/IO

IO for Elm

IO in Elm

This repo provides a library for writing console-based programs in Elm.

Example

An elm Program:

module Main where

import IO.IO (..)
import IO.Runner exposing (Request, Response)
import IO.Runner as IO

import List
import Maybe
import String

echo : IO ()
echo = forever (getLine >>= putStrLn)

loop : IO ()
loop = getLine >>= \s ->
       if s == "exit"
       then pure ()
       else putStrLn s >>> loop
       
hello : IO ()
hello = putStrLn "Hello, Console!" >>>
        putStrLn "I'll echo your input until you say \"exit\":" >>>
        loop >>>
        putStrLn "That's all, folks!" >>>
        exit 0

port requests : Signal Request
port requests = IO.run responses hello

port responses : Signal Response

link in some javascript and then run:

$ elm-make --yes Test.elm raw-test.js
...
$ ./elm-io.sh raw-test.js test.js
$ node test.js
Hello, Console!
I'll echo your input:
hooray
hooray
That's all, folks!

Command Line Interface

The basic interface is elm-io.sh infile outfile, where infile is a compiled Elm file with requests and response signals set up as above and outfile is the desired filename for the compiled output.

Design and Implementation

The implementation is based on the IOSpec haskell library.