libghc-ghc-typelits-knownnat-dev 0.7.7-1build1 (amd64 binary) in ubuntu lunar
A type checker plugin for GHC that can derive "complex" KnownNat
constraints from other simple/variable KnownNat constraints. i.e. without
this plugin, you must have both a KnownNat n and a KnownNat (n+2)
constraint in the type signature of the following function:
.
f :: forall n . (KnownNat n, KnownNat (n+2)) => Proxy n -> Integer
f _ = natVal (Proxy :: Proxy n) + natVal (Proxy :: Proxy (n+2))
.
Using the plugin you can omit the KnownNat (n+2) constraint:
.
f :: forall n . KnownNat n => Proxy n -> Integer
f _ = natVal (Proxy :: Proxy n) + natVal (Proxy :: Proxy (n+2))
.
The plugin can derive KnownNat constraints for types consisting of:
.
* Type variables, when there is a corresponding KnownNat constraint
.
* Type-level naturals
.
* Applications of the arithmetic expression: +,-,*,^
.
* Type functions, when there is either:
.
1. a matching given KnownNat constraint; or
.
2. a corresponding KnownNat<N> instance for the type function
.
To use the plugin, add the
.
OPTIONS_GHC -fplugin GHC.TypeLits.
.
Pragma to the header of your file.
.
This package provides a library for the Haskell programming language.
See http://
Details
- Package version:
- 0.7.7-1build1
- Status:
- Published
- Component:
- universe
- Priority:
- Optional
Downloadable files
Package relationships
- Depends on:
- libc6 (>= 2.2.5)
- libghc-base-dev-4.15.1.0-6a406
- libghc-ghc-dev-9.0.2-740f7
- libghc-ghc-prim-dev-0.7.0-65cf5
- libghc-ghc-tcplugins-extra-dev-0.4.3-22827
- libghc-ghc-typelits-natnormalise-dev-0.7.7-a70c4
- libghc-template-haskell-dev-2.17.0.0-7274a
- libghc-transformers-dev-0.5.6.2-fc6f3
- libgmp10 (>= 2:6.2.1+dfsg1)
- libtinfo6 (>= 6)
- Provides:
- libghc-ghc-typelits-knownnat-dev-0.7.7-da5ee