https://github.com/athanclark/elm-threading

A simple threading patch for elm ports
https://github.com/athanclark/elm-threading

elm threading

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A simple threading patch for elm ports

• Host: GitHub
• URL: https://github.com/athanclark/elm-threading
• Owner: athanclark
• Created: 2016-06-18T08:07:29.000Z (over 8 years ago)
• Default Branch: master
• Last Pushed: 2016-06-25T03:13:14.000Z (over 8 years ago)
• Last Synced: 2023-08-08T20:37:50.833Z (over 1 year ago)
• Topics: elm, threading
• Language: Elm
• Size: 3.91 KB
• Stars: 4
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# elm-threading

A simple method for managing asynchronous ports that may be flooded

with invocations:

```elm

-- a simple hashing module

module Hash exposing (..)

import Threading

import Task

type alias Hashed = String

port makeHash : String -> Cmd a

port madeHash : (Hashed -> a) -> Sub a

type Msg a

  = ThreadingMsg (Threading.Msg String Hashed Msg)

  | HashThis String (Hashed -> Cmd a)

type alias Model a =

  { threading : Threading.Model Hashed (Msg a)

  }

  

init : (Model a, Cmd (Msg a))

init = ({ threading = Threading.init }, Cmd.none )

update : Msg a -> Model a -> (Model a, Cmd a)

update action model =

  case action of

    ThreadingMsg a ->

      let (newThreading, threadingCmd) =

            Threading.update makeHash a model.threading

      in  ( { model | threading = newThreading }

          , Cmd.map (\r -> case r of

                             Err a -> ThreadingMsg a

                             Ok a  -> a) threadingCmd

          )

    HashThis toHash whenComplete ->

      ( model

      , Task.perform Debug.crash ThreadingMsg

          <| Task.succeed <| Threading.Call toHash whenComplete

      )

subscriptions : Sub (Msg a)

subscriptions = Sub.map ThreadingMsg

             <| Threading.subscriptions madeHash

```

Bam! Continuation-style passing for javascript ports. Note that

we leave `a` here - we still need the user of this module to pass

their "handler" for when the port finishes, but that's okay by

my book. If you have serious complaints, you should use sticks

and rocks instead of your computer.

> It may be easier to use

> [Shmookey's Cmd.Extra](http://package.elm-lang.org/packages/shmookey/cmd-extra/1.0.0/Cmd-Extra)

> instead of constantly doing `Task.perform Debug.crash identity << Task.succeed`

> all over teh place

```js

app.ports.makeHash.subscribe(function(threadedInput) {

  var threadedOutput = {

    threadId = threadedInput.threadId,

    payload  = hash(threadedInput.payload) // something async or w/e

  };

  app.ports.madeHash.send(threadedOutput);

});

```