functor-combinators-0.2.0.0: Tools for functor combinator-based program design

Data.Functor.Combinator.Unsafe

Description

Working with non-standard typeclasses like Plus, Apply, Bind, and Pointed will sometimes cause problems when using with libraries that do not provide instances, even though their types already are instances of Alternative or Applicative or Monad.

This module provides unsafe methods to "promote" Applicative instances to Apply, Alternative to Plus, etc.

They are unsafe in the sense that if those types already have those instances, this will cause overlapping instances errors or problems with coherence. Because of this, you should always use these with specific fs, and never in a polymorphic way over f.

Synopsis

# Documentation

unsafePlus :: forall f proxy r. Alternative f => proxy f -> (Plus f => r) -> r Source #

For any Alternative f, produce a value that would require Plus f.

Always use with concrete and specific f only, and never use with any f that already has a Plus instance.

See documentation for upgradeC for example usages.

The Proxy argument allows you to specify which specific f you want to enhance. You can pass in something like Proxy @MyFunctor.

unsafeApply :: forall f proxy r. Applicative f => proxy f -> (Apply f => r) -> r Source #

For any Applicative f, produce a value that would require Apply f.

Always use with concrete and specific f only, and never use with any f that already has a Apply instance.

See documentation for upgradeC for example usages.

The Proxy argument allows you to specify which specific f you want to enhance. You can pass in something like Proxy @MyFunctor.

unsafeBind :: forall f proxy r. Monad f => proxy f -> (Bind f => r) -> r Source #

For any Monad f, produce a value that would require Bind f.

Always use with concrete and specific f only, and never use with any f that already has a Bind instance.

See documentation for upgradeC for example usages.

The Proxy argument allows you to specify which specific f you want to enhance. You can pass in something like Proxy @MyFunctor.

unsafePointed :: forall f proxy r. Applicative f => proxy f -> (Pointed f => r) -> r Source #

For any Applicative f, produce a value that would require Pointed f.

Always use with concrete and specific f only, and never use with any f that already has a Pointed instance.

See documentation for upgradeC for example usages.

The Proxy argument allows you to specify which specific f you want to enhance. You can pass in something like Proxy @MyFunctor.