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.
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Flags
Manual Flags
| Name | Description | Default |
|---|---|---|
| hashable | You can disable the use of the Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. If disabled we will not supply instances of Note: `-f-hashable` implies `-f-unordered-containers`, as we are necessarily not able to supply those instances as well. | Enabled |
| binary | You can disable the use of the Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. | Enabled |
| bytestring | You can disable the use of the Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. | Enabled |
| containers | You can disable the use of the Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. | Enabled |
| deepseq | You can disable the use of the Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. | Enabled |
| tagged | You can disable the use of the Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. | Enabled |
| text | You can disable the use of the Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. | Enabled |
| transformers | You can disable the use of the Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. | Enabled |
| unordered-containers | You can disable the use of the `unordered-containers` package using `-f-unordered-containers`. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. | Enabled |
Automatic Flags
| Name | Description | Default |
|---|---|---|
| bytestring-builder | Decides whether to use an older version of bytestring along with bytestring-builder or just a newer version of bytestring. This flag normally toggles automatically but you can use `-fbytestring-builder` or `-f-bytestring-builder` to explicitly change it. | Disabled |
Use -f <flag> to enable a flag, or -f -<flag> to disable that flag. More info
Downloads
- semigroups-0.18.5.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 |
|---|---|
| Change log | CHANGELOG.markdown |
| Dependencies | base (>=2 && <5), binary, bytestring (>=0.9 && <1), bytestring-builder (>=0.10.4 && <1), containers (>=0.3 && <0.7), deepseq (>=1.1 && <1.5), ghc-prim, hashable (>=1.1.1.0 && <1.3), nats (>=0.1 && <2), tagged (>=0.4.4 && <1), text (>=0.10 && <2), transformers (>=0.2 && <0.6), transformers-compat (>=0.5 && <1), unordered-containers (>=0.2 && <0.3) [details] |
| License | BSD-3-Clause |
| Copyright | Copyright (C) 2011-2015 Edward A. Kmett |
| Author | Edward A. Kmett |
| Maintainer | Edward A. Kmett <ekmett@gmail.com> |
| Revised | Revision 1 made by phadej at 2019-05-24T14:28:30Z |
| 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 ryanglscott at 2018-07-02T22:09:56Z |
| 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, 13957 indirect [details] |
| Downloads | 487332 total (483 in the last 30 days) |
| Rating | 2.75 (votes: 9) [estimated by Bayesian average] |
| Your Rating | |
| Status | Docs available [build log] Last success reported on 2018-07-02 [all 1 reports] |
Readme for semigroups-0.18.5
[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.
Data.Semigroup and Data.List.NonEmpty were added to base as of 4.9.0.0. This package now offers a backwards-compatible API and some tools for deriving semigroups with generics.
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