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GHC 9.10.3 · lts/ghc-9.10.x · c74966e · 2026-09-27

Moduleselective-0.7.0.1Haskell2010

Control.Selective.Trans.Except

This is a library for selective applicative functors, or just selective functors for short, an abstraction between applicative functors and monads, introduced in this paper: https://dl.acm.org/doi/10.1145/3341694.

This module defines a newtype around ExceptT from transformers with less restrictive Applicative, Selective, and Alternative implementations. It supplies an instance Selective f => Selective (ExceptT e f), which makes ExceptT a bona-fide Selective transformer.

The API follows the API from the transformers package, so it can be used as a drop-in replacement. The documentation can be found in the transformers package.

  • 2 types
  • 13 values
newtypenewtype ExceptT e (f :: Type -> Type) a
#

A newtype wrapper around ExceptT from transformers that provides less restrictive Applicative, Selective and Alternative instances.

Constructors

Instances21Monad, Functor, MonadFix, MonadFail, Applicative, Foldable, …