flow-1.0.21: README.markdown
# [Flow][]
[](https://travis-ci.org/tfausak/flow)
[](https://hackage.haskell.org/package/flow)
[](https://www.stackage.org/package/flow)
Write more understandable Haskell.
Flow is a package that provides functions and operators for writing more
understandable Haskell. It is an alternative to some common idioms like
[`($)`][] for function application and [`(.)`][] for function composition.
- [Requirements](#requirements)
- [Installation](#installation)
- [Usage](#usage)
- [Cheat sheet](#cheat-sheet)
## Requirements
Flow requires a Haskell compiler. It is tested with recent versions of GHC, but
older or different compilers should be acceptable. For installation with Cabal,
Flow requires at least Cabal 1.8.
## Installation
To add Flow as a dependency to your package, add it to your Cabal file.
```
build-depends: flow ==1.0.*
```
## Usage
Flow is designed to be imported unqualified. It does not export anything that
conflicts with [the base package][].
``` hs
import Flow
```
### Cheat sheet
Flow | Base
--------------- | -------------
<code>x |> f</code> | `x & f`
<code>f <| x</code> | `f $ x`
`apply x f` | `f x`
`f .> g` | `f >>> g`
`g <. f` | `g . f`
`compose f g x` | `g (f x)`
`x !> f` | -
`f <! x` | `f $! x`
`apply' x f` | `seq x (f x)`
### Converting existing code
If you want to uniformly use flow operators you can use [HLint] with the
`hlint-flow.yaml` file. For easy use, it is best to extract the
`hlint-flow.yaml` to your project directory and do
``` sh
> hlint -h hlint-flow.yaml <source file>
```
or
``` sh
> hlint --git -h hlint-flow.yaml
```
to check all Haskell source tracked by git.
For more information about Flow, please read [the Haddock documentation][].
[HLint]: https://github.com/ndmitchell/hlint
[Flow]: http://taylor.fausak.me/flow/
[`($)`]: http://hackage.haskell.org/package/base-4.8.0.0/docs/Prelude.html#v:-36-
[`(.)`]: http://hackage.haskell.org/package/base-4.8.0.0/docs/Prelude.html#v:.
[the base package]: http://hackage.haskell.org/package/base
[the haddock documentation]: https://hackage.haskell.org/package/flow/docs/Flow.html