interval-functor: Intervals of functors.

[ bsd3, data, library ] [ Propose Tags ]

Closed intervals in spaces described by a functor.

[Skip to Readme]


[Index] [Quick Jump]


Maintainer's Corner

Package maintainers

For package maintainers and hackage trustees


Versions [RSS]
Change log
Dependencies base (>=4.10 && <5), transformers (>= && <0.6) [details]
License BSD-3-Clause
Copyright 2018-2020 Rob Rix
Author Rob Rix
Category Data
Home page
Bug tracker
Source repo head: git clone
Uploaded by robrix at 2020-07-11T22:49:22Z
Downloads 284 total (11 in the last 30 days)
Rating (no votes yet) [estimated by Bayesian average]
Your Rating
  • λ
  • λ
  • λ
Status Docs uploaded by user
Build status unknown [no reports yet]

Readme for interval-functor-

[back to package description]


This is a Haskell package defining an Interval datatype parameterized by the type of endpoints and the type of their coordinates. For example, it can represent a simple one-dimensional range:

import Data.Functor.Identity
import Data.Functor.Interval

zeroInterval :: Num a => Interval Identity a
zeroInterval = point 0

or a multi-dimensional region:

import Data.Functor.Interval
import Linear.V3 -- from the linear package

unitCube :: Num a => Interval V3 a
unitCube = (-1)...1


Development currently assumes a Mac with ghc 8.10 & cabal 3.0. You can install them directly, or use ghcup. It should be possible to develop on other platforms and compilers, but I probably haven’t tried them myself.

cabal build --enable-tests # initial build
script/repl # load the library and tests in ghci

Once the repl has loaded, you can run the tests with :main.

λ :main

Configuration exists for ghcide, which can be integrated into many editors.


interval-functor separates the representation of the coordinates of an interval from the representation of the space the coordinates occur in. This makes it particularly suitable for consistent treatment of multi-dimensional intervals; operations like e.g. union extend naturally to multi-dimensional spaces.

It is also thoroughly property tested and documented.