between

Function combinator "between" and derived combinators

LTS Haskell 23.21:	0.11.0.0
Stackage Nightly 2025-05-06:	0.11.0.0
Latest on Hackage:	0.11.0.0

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BSD-3-Clause licensed by Peter Trško

Maintained by peter.trsko@gmail.com

This version can be pinned in stack with:between-0.11.0.0@sha256:05c82afced3a60a6e7d624d6c1d410f6b1d3de264a663cc53237bef4b63e0322,2463

Module documentation for 0.11.0.0

Data
- Data.Function
  - Data.Function.Between

Depends on 1 package(full list with versions):

base

Between

Description

It turns out that this combinator

f ~@~ g = (f .) . (. g)

is a powerful thing. It was abstracted from following (commonly used) pattern f . h . g where f and g are fixed.

This library not only define ~@~ combinator, but also some derived combinators that can help us to easily define a lot of things including lenses. See lens package for detais on what lenses are.

Function Data.Function.on can be implemented using ~@~ as:

on :: (b -> b -> c) -> (a -> b) -> a -> a -> c
on f g = (id ~@~ g ~@~ g) f

If function @on3@ existed in /base/ then it could be defined as:

on3 :: (b -> b -> b -> d) -> (a -> b) -> a -> a -> a -> d
on3 f g = (id ~@~ g ~@~ g ~@~ g) f

For more examples see documentation.

Documentation

Stable releases with API documentation are available on Hackage.

Building Options

-fpedantic (disabled by default)

Pass additional warning flags to GHC.

License

The BSD 3-Clause License, see LICENSE file for details.

Contributions

Contributions, pull requests and bug reports are welcome! Please don’t be afraid to contact author using GitHub or by e-mail (see .cabal file for that).

Changes

ChangeLog / ReleaseNotes

Version 0.11.0.0

New function application combinators (new):
- inbetween :: a -> b -> (a -> b -> r) -> r
- (~$~) :: a -> b -> (a -> b -> r) -> r
- (~$$~) :: b -> a -> (a -> b -> r) -> r
- withIn :: ((a -> b -> r) -> r) -> (a -> b -> r) -> r
- withReIn :: ((b -> a -> r) -> r) -> (a -> b -> r) -> r
Precursors to Iso, Lens and Prism (new):
- type PreIso r s t a b = ((b -> t) -> (s -> a) -> r) -> r
- type PreIso' r s a = PreIso r s s a a
- type PreLens r s t a b = ((b -> s -> t) -> (s -> a) -> r) -> r
- type PreLens' r s a = PreLens r s s a a
- type PrePrism r s t a b = ((b -> t) -> (s -> Either t a) -> r) -> r
- type PrePrism' r s a = PrePrism r s s a a
Uploaded to Hackage: http://hackage.haskell.org/package/between-0.11.0.0

Version 0.10.0.0

Original implementation moved to module Data.Function.Between.Lazy and is now reexported by Data.Function.Between. (new)
Implementation of strict variants of all functions defined in Data.Function.Between.Lazy module. These new functions use (f . g) x = f '$!' g '$!' x as definition for function composition where $! is strict application. (new)
Uploaded to Hackage: http://hackage.haskell.org/package/between-0.10.0.0

Version 0.9.0.2

Minor documentation changes.
Resolving some Haddock issues in documentation.
Uploaded to Hackage: http://hackage.haskell.org/package/between-0.9.0.2

Version 0.9.0.1

Removing all INLINE and RULES. Tested it using ghc-core with GHC 7.8.3 (bundled with Haskell Platform 2014.2.0.0) and it works well.
Uploaded to Hackage: http://hackage.haskell.org/package/between-0.9.0.1

Version 0.9.0.0

First public release.
Uploaded to Hackage: http://hackage.haskell.org/package/between-0.9.0.0