errors

Simplified error-handling

Version on this page:2.1.3
LTS Haskell 23.27:2.3.0@rev:5
Stackage Nightly 2025-07-13:2.3.0@rev:5
Latest on Hackage:2.3.0@rev:5

See all snapshots errors appears in

BSD-3-Clause licensed by Gabriel Gonzalez
Maintained by [email protected]
This version can be pinned in stack with:errors-2.1.3@sha256:9aa0f7e5a05f0b8ed77067682837d7c05a88d5c046b3e8f3401536ce623ce3d0,1334

Module documentation for 2.1.3

The one-stop shop for all your error-handling needs! Just import Control.Error.

This library encourages an error-handling style that directly uses the type system, rather than out-of-band exceptions.

Changes

2.1.1

  • Increase upper bound on transformers-compat

2.1.0

  • Change syncio to use unexceptionalio to prove that all synchronous exceptions were caught and handled

2.0.0

  • Switch from EitherT to ExceptT

1.4.7

  • Increase upper bound on transformers from 0.4 to 0.5

1.4.6

  • Add bool
  • Add (?:)
  • Add isJustT
  • Add isNothingT
  • Add isLeftT
  • Add isRightT

1.4.5

  • Increase upper bound on either from 4.1 to 5

1.4.4

  • Add failWith
  • Add failWithM

1.4.3

  • Add AllE
  • Add AnyE
  • Increase upper bound on either from 3.5 to 4.1

1.4.2

  • Add (??)
  • Add (!?)
  • Add syncIO

1.4.1

  • Re-export EitherT
  • Re-export MaybeT

1.4.0

  • Add maybeT
  • Add just
  • Add nothing
  • Add upper bound to either
  • Add upper bound to safe
  • Add upper bound to transformers

1.3.1

  • Increase lower bound on transformers from 0.2 to 0.3.0.0

1.3.0

  • Add assertMay
  • Add rightMay
  • Add justErr
  • Add tryJust
  • Add tryRight
  • Add MonadPlus functions to Control.Error.Safe
  • Add isLeft
  • Add isRight
  • Add fmapR
  • Add fmapRT
  • Add err
  • Add errLn
  • Add flipE
  • Add flipET
  • Rename tryIO to scriptIO
  • Remove tryMaybe
  • Remove tryEither
  • Rename liftMaybe to hoistMaybe
  • Rename liftEither to hoistEither

1.2.1

  • Add lower bound to either

1.2.0

  • Remove right
  • Remove left

1.1.1

  • Cosmetic changes

1.1.0

  • Add left

1.0.0

  • Initial release