https://github.com/bodil/purescript-observable

ES7 Observables for PureScript
https://github.com/bodil/purescript-observable

Last synced: 23 days ago
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ES7 Observables for PureScript

• Host: GitHub
• URL: https://github.com/bodil/purescript-observable
• Owner: bodil
• Created: 2016-01-11T16:24:35.000Z (almost 9 years ago)
• Default Branch: master
• Last Pushed: 2017-03-09T21:49:00.000Z (almost 8 years ago)
• Last Synced: 2024-04-15T12:19:16.376Z (8 months ago)
• Language: PureScript
• Homepage:
• Size: 35.2 KB
• Stars: 29
• Watchers: 6
• Forks: 1
• Open Issues: 1
• Metadata Files:
  • Readme: README.md

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README

        
# purescript-observable

Observables for PureScript, compatible with the

[ECMAScript Observable proposal](https://github.com/zenparsing/es-observable).

* [API docs on Pursuit](http://pursuit.purescript.org/packages/purescript-observable/)

## Usage

A basic usage example:

```purescript

module Main where

import Prelude

import Control.Monad.Eff.Console (log)

import Control.Monad.Eff.Exception (message)

import Control.Observable (fromFoldable, subscribe)

import Data.String (toUpper)

main = do

  let o = toUpper <$> fromFoldable ["hello", "world"]

  subscribe {

    next: log,

    error: message >>> log,

    complete: pure unit

    } o

```

Creating custom streams:

```purescript

module Main where

import Prelude

import Control.Monad.Eff.Console (log)

import Control.Monad.Eff.Exception (message)

import Control.Observable (observable, subscribe, free)

main = do

  o <- observable \sink -> do

    sink.next "Hello Joe"

    sink.next "Hello Mike"

    sink.next "Hello Robert"

    sink.complete

    free []

  -- `observe` is a shorthand for `subscribe`

  observe log (message >>> log) (pure unit) o

```

## ECMAScript Observable Compatibility

The observables created by this library should be fully compatible

with the

[ECMAScript Observable proposal](https://github.com/zenparsing/es-observable).

You should also be able to consume any observable implementing the

specification using this library, if you cast it to the `Observable`

type.

## FAQ

Q: Why isn't every operation effectful?

A: Only operations which may need to utilise effects themselves are

effectful. This includes creating new observables, subscribing to an

observable, and not much else. Creating a new observable by eg.

mapping a pure function over an existing observable is itself a pure

function - it's true that if you perform such an operation twice

you'll have two different observables, but they'll always emit the

exact same events at the exact same time, meaning that they have value

equality.

## Licence

Copyright 2016 Bodil Stokke

This program is free software: you can redistribute it and/or modify

it under the terms of the GNU Lesser General Public License as

published by the Free Software Foundation, either version 3 of the

License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but

WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public

License along with this program. If not, see

.