semigroups: Anything that associates
In mathematics, a semigroup is an algebraic structure consisting of a set together with an associative binary operation. A semigroup generalizes a monoid in that there might not exist an identity element. It also (originally) generalized a group (a monoid with all inverses) to a type where every element did not have to have an inverse, thus the name semigroup.
[Skip to Readme]
Flags
Automatic Flags
| Name | Description | Default |
|---|---|---|
| base2 | Disabled |
Use -f <flag> to enable a flag, or -f -<flag> to disable that flag. More info
Downloads
- semigroups-0.13.tar.gz [browse] (Cabal source package)
- Package description (revised from the package)
Note: This package has metadata revisions in the cabal description newer than included in the tarball. To unpack the package including the revisions, use 'cabal get'.
Maintainer's Corner
For package maintainers and hackage trustees
Candidates
| Versions [RSS] | 0.1.0, 0.2.0, 0.3.0, 0.3.1, 0.3.2, 0.3.3, 0.3.4, 0.3.4.1, 0.3.4.2, 0.4.0, 0.5.0, 0.5.0.1, 0.5.0.2, 0.6, 0.6.1, 0.7.0, 0.7.1, 0.7.1.1, 0.7.1.2, 0.8, 0.8.0.1, 0.8.2, 0.8.3, 0.8.3.1, 0.8.3.2, 0.8.4, 0.8.4.1, 0.8.5, 0.9, 0.9.1, 0.9.2, 0.10, 0.11, 0.12, 0.12.0.1, 0.12.1, 0.12.2, 0.13, 0.13.0.1, 0.14, 0.15, 0.15.1, 0.15.2, 0.15.3, 0.15.4, 0.16, 0.16.0.1, 0.16.1, 0.16.2, 0.16.2.1, 0.16.2.2, 0.17, 0.17.0.1, 0.18, 0.18.0.1, 0.18.1, 0.18.2, 0.18.3, 0.18.4, 0.18.5, 0.19, 0.19.1, 0.19.2, 0.20 |
|---|---|
| Dependencies | base (>=2 && <4.5 || >=4.6 && <5), bytestring (>=0.9 && <1), containers (>=0.3 && <0.6), hashable (>=1.1 && <1.3), nats (>=0.1 && <1), text (>=0.10 && <2), unordered-containers (>=0.2 && <0.3) [details] |
| License | BSD-3-Clause |
| Copyright | Copyright (C) 2011-2014 Edward A. Kmett |
| Author | Edward A. Kmett |
| Maintainer | Edward A. Kmett <ekmett@gmail.com> |
| Revised | Revision 1 made by HerbertValerioRiedel at 2014-12-29T18:08:13Z |
| Category | Algebra, Data, Data Structures, Math |
| Home page | http://github.com/ekmett/semigroups/ |
| Bug tracker | http://github.com/ekmett/semigroups/issues |
| Source repo | head: git clone git://github.com/ekmett/semigroups.git |
| Uploaded | by EdwardKmett at 2014-04-09T14:02:14Z |
| Distributions | Debian:0.19.1, Fedora:0.20, FreeBSD:0.16.2.2, LTSHaskell:0.20, NixOS:0.20, Stackage:0.20, openSUSE:0.20 |
| Reverse Dependencies | 908 direct, 14013 indirect [details] |
| Downloads | 488034 total (419 in the last 30 days) |
| Rating | 2.75 (votes: 9) [estimated by Bayesian average] |
| Your Rating | |
| Status | Docs available [build log] Successful builds reported [all 1 reports] |
Readme for semigroups-0.13
[back to package description]semigroups
Haskellers are usually familiar with monoids. A monoid has an appending operation <> or mappend and an identity element mempty. A Semigroup has an append <>, but does not require an mempty element. A Monoid can be made a Semigroup with just instance Semigroup MyMonoid
More formally, a semigroup is an algebraic structure consisting of a set together with an associative binary operation. A semigroup generalizes a monoid in that there might not exist an identity element. It also (originally) generalized a group (a monoid with all inverses) to a type where every element did not have to have an inverse, thus the name semigroup.
Semigroups appear all over the place, except in the Haskell Prelude, so they are packaged here.
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