parameterized-utils-2.1.11.0: Classes and data structures for working with data-kind indexed types

Copyright | (c) Galois Inc 2014-2019
Maintainer | Langston Barrett <langston@galois.com>
Safe Haskell | Safe
Language | Haskell2010

Data.Parameterized.Compose

Description

Utilities for working with Data.Functor.Compose.

NB: This module contains an orphan instance. It will be included in GHC 8.10, see https://gitlab.haskell.org/ghc/ghc/merge_requests/273 and also https:/github.comhaskell-compatbase-orphansissues/49.

Synopsis

- testEqualityComposeBare :: forall k l f (g :: l -> k) (x :: l) (y :: l). (forall (w :: k) (z :: k). f w -> f z -> Maybe (w :~: z)) -> Compose f g x -> Compose f g y -> Maybe (x :~: y)

# Documentation

testEqualityComposeBare :: forall k l f (g :: l -> k) (x :: l) (y :: l). (forall (w :: k) (z :: k). f w -> f z -> Maybe (w :~: z)) -> Compose f g x -> Compose f g y -> Maybe (x :~: y) Source #

The deduction (via generativity) that if `g x :~: g y` then `x :~: y`.

See https://gitlab.haskell.org/ghc/ghc/merge_requests/273.