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GHC 10.0.0.20260917 · lts/ghc-10.0.x · 2b27632 · 2026-10-31

Modulepolysemy-1.9.2.0Haskell2010

Polysemy.Fail.Type

Synopsis
  • Packagepolysemy-1.9.2.0
  • Exports1
  • LanguageHaskell2010
  • LicenceBSD-3-Clause
  • SourceType.hs
newtypenewtype Fail (m :: k) (a :: k1)

This effect abstracts the concept of Control.Monad.Fail.MonadFail, which is a built-in mechanism that converts pattern matching errors to calls to the current monad's instance of that class.

The instance defined in Polysemy.Internal uses this effect to catch those errors.

Constructors