typenums: Type level numbers using existing Nat functionality
This is a package candidate release! Here you can preview how this package release will appear once published to the main package index (which can be accomplished via the 'maintain' link below). Please note that once a package has been published to the main package index it cannot be undone! Please consult the package uploading documentation for more information.
Type level numbers using existing Nat functionality. Uses kind-polymorphic typeclasses and type families to facilitate more general code compatible with existing code using type-level Naturals.
[Skip to Readme]
Properties
| Versions | 0.1.0.0, 0.1.1, 0.1.1.1, 0.1.2, 0.1.2.1, 0.1.3, 0.1.4, 0.1.4 |
|---|---|
| Change log | CHANGELOG.md |
| Dependencies | base (>=4.10 && <5.0) [details] |
| License | BSD-3-Clause |
| Copyright | 2018-2021 Iris Ward |
| Author | AdituV |
| Maintainer | aditu.venyhandottir@gmail.com |
| Category | Data |
| Home page | https://github.com/adituv/typenums#readme |
| Bug tracker | https://github.com/adituv/typenums/issues |
| Source repo | head: git clone https://github.com/adituv/typenums |
| Uploaded | by AdituV at 2021-03-22T23:29:42Z |
Modules
[Index] [Quick Jump]
Downloads
- typenums-0.1.4.tar.gz [browse] (Cabal source package)
- Package description (as included in the package)
Maintainer's Corner
Package maintainers
For package maintainers and hackage trustees
Readme for typenums-0.1.4
[back to package description]typenums
Type level numbers using existing Nat functionality. Uses kind-polymorphic typeclasses and type families to facilitate more general code compatible with existing code using type-level Naturals.
Usage
Import either Data.TypeNums or Data.TypeLits instead of GHC.TypeLits. Some definitions conflict with GHC.TypeLits, so if you really must import it, use an explicit import list.
This library is intended to be used in a kind-polymorphic way, such that a type-level integer parameter can be written as a natural, and a rational can be written as either of the other two. As an example:
{-# LANGUAGE PolyKinds #-}
data SomeType (n :: k) = SomeType
useSomeType :: KnownInt n => SomeType n -> _
useSomeType = -- ...
Syntax
- Positive integers are written as natural numbers, as before. Optionally
they can also be written as
Pos n. - Negative integers are written as
Neg n. - Ratios are written as
n :% d, wherencan be a natural number,Pos n, orNeg n, anddis a natural number.
Addition, subtraction and multiplication at type level are all given as infix operators with standard notation, and are compatible with any combination of the above types. Equality and comparison constraints are likewise available for any combination of the above types.
N.B. The equality constraint conflicts with that in Data.Type.Equality. The (==) operator from Data.Type.Equality is re-exported as (==?) from both Data.TypeNums and Data.TypeLits.