https://github.com/bgamari/monoidal-containers

Maps using values' monoidal structure during merging
https://github.com/bgamari/monoidal-containers

Last synced: 6 months ago
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Maps using values' monoidal structure during merging

• Host: GitHub
• URL: https://github.com/bgamari/monoidal-containers
• Owner: bgamari
• License: other
• Created: 2015-01-20T16:57:34.000Z (over 11 years ago)
• Default Branch: master
• Last Pushed: 2025-04-05T16:47:51.000Z (over 1 year ago)
• Last Synced: 2025-04-12T23:42:04.031Z (over 1 year ago)
• Language: Haskell
• Homepage:
• Size: 184 KB
• Stars: 42
• Watchers: 6
• Forks: 33
• Open Issues: 9
• Metadata Files:
  • Readme: README.md
  • Changelog: Changelog.md
  • License: LICENSE

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README

          
# monoidal-containers

[![Haskell](https://img.shields.io/badge/language-Haskell-orange.svg)](https://haskell.org) [![Hackage](https://img.shields.io/hackage/v/monoidal-containers.svg)](https://hackage.haskell.org/package/monoidal-containers) [![Hackage CI](https://matrix.hackage.haskell.org/api/v2/packages/monoidal-containers/badge)](https://matrix.hackage.haskell.org/#/package/monoidal-containers) [![Github CI](https://github.com/bgamari/monoidal-containers/workflows/Cabal/badge.svg)](https://github.com/bgamari/monoidal-containers/actions) [![BSD3 License](https://img.shields.io/badge/license-BSD3-blue.svg)](https://github.com/bgamari/monoidal-containers/blob/master/LICENSE)

Often when working with the containers offered by the `containers` and 

`unordered-containers` packages one would prefer the monoidal structure 

of the values to be used when resolving conflicts between keys when merging 

structures. Sadly, these are not the semantics offered by the provided

instances. This package provides `newtypes` with an appropriate set of

instances and utility functions to make them usable.

## Important Note

This library is designed to be a drop-in replacement for `Data.Map` and similar. Absolutely no other semantic changes are introduced in functions like `fromList` or `insert`. They are still left-biased like `Data.Map`'s. The only difference is in instances for `Semigroup`.