| Name : ghc-ghc-typelits-knownnat
| |
| Version : 0.3
| Vendor : openSUSE
|
| Release : bp150.1.3
| Date : 2018-07-30 21:13:22
|
| Group : Development/Languages/Other
| Source RPM : ghc-ghc-typelits-knownnat-0.3-bp150.1.3.src.rpm
|
| Size : 0.09 MB
| |
| Packager : https://bugs_opensuse_org
| |
| Summary : Derive KnownNat constraints from other KnownNat constraints
|
Description :
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.KnownNat.Solver \'
Pragma to the header of your file.
|
RPM found in directory: /packages/linux-pbone/ftp5.gwdg.de/pub/opensuse/repositories/openSUSE:/Backports:/SLE-15/standard/x86_64 |
