semigroupoids

Semigroupoids: Category sans id

http://github.com/ekmett/semigroupoids

Version on this page:5.1
LTS Haskell 23.19:6.0.1@rev:2
Stackage Nightly 2025-04-30:6.0.1@rev:2
Latest on Hackage:6.0.1@rev:2

See all snapshots semigroupoids appears in

BSD-3-Clause licensed by Edward A. Kmett
Maintained by Edward A. Kmett
This version can be pinned in stack with:semigroupoids-5.1@sha256:f4bb46d66416e901da3fd5e5df5dbe8c122d1202f7774162096c7216efad0b91,6330

Module documentation for 5.1

semigroupoids

Hackage Build Status

A semigroupoid is a Category without id.

Contact Information

Contributions and bug reports are welcome!

Please feel free to contact me through github or on the #haskell IRC channel on irc.freenode.net.

-Edward Kmett

Changes

5.1

  • The remaining orphan instances in Data.Traversable.Instances have been replaced in favor of the orphan instances from transformers-compat-0.5.
  • The documentation now states laws that instances of Apply are expected to uphold.
  • doctest-0.11 support
  • Fixed compilation of tests with stack

5.0.1

  • transformers-compat 0.5 support
  • Removed some redundant constraints.
  • GHC 8 support

5.0.0.4

  • doctest 0.10 support

5.0.0.2

  • Bugfix for GHC 7.4. PolyKinds on 7.4 cause all sorts of haskell interface file errors. One of the #if guards that turned it off on 7.4 was missing and has been fixed.

5.0.0.1

  • Added the CHANGELOG to the distribution so that hackage can link to it in the haddocks.

5

  • Absorbed Data.Bifunctor.Apply, Data.Semigroup.Bifoldable and Data.Semigroup.Traversable from bifunctors.
  • This caused us to pick up a dependency on tagged.
  • Exiled Data.Semifunctor.*, Data.Semigroupoid.Product and Data.Semigroupoid.Coproduct to semigroupoid-extras.
  • This let us open up to older versions of GHC again.
  • Set an explicit fixity for -<- and ->-.

4.5

  • Major changes to the API to support PolyKinds and DataKinds. This necessarily shuts off GHC <= 7.4.
  • Orphan instances have moved upstream into a common base-orphans package.

4.3.1

  • Added asum1 to Data.Semigroup.Foldable.

4.3.0.1

  • Support for ‘ConstrainedClassMethods’ is currently required for GHC HEAD.

4.3

  • Added missing instances for ExceptT. Obtain it via transformers-compat if need be for old transformers versions.
  • Several Bind and Apply instances now require somewhat more minimal contexts.

4.2

  • Backported Foldable/Traversable instances from lens

4.1

  • Foldable1/Traversable1 for tuples

4.0.4

  • contravariant 1.0 support.

4.0.3

  • Added flags to provide unsupported cabal sandbox build modes.

4.0.1

  • Fixed bitrot in the Data.Functor.Extend documentation.
  • Fixed warnings on GHC 7.8.1rc2 caused by importing Control.Monad.Instances.

4.0

  • Merged in the contents of the groupoids and semigroupoid-extras packages.

3.1

  • Added the rectangular band Semigroupoid for (,). Would that make it a Bandoid?

3.0.3

  • Claim to be Trustworthy where necessary

3.0.2

  • Tightened the upper bounds slightly to enable PVP compliance while retaining a flexible development cycle.
  • Raised the upper bound on contravariant.

3.0.1

  • Removed upper bounds relative to my other packages
  • Refactored directory layout