https://github.com/sgraf812/pomaps

Haskell data structure for maps and sets with partially ordered keys
https://github.com/sgraf812/pomaps

Last synced: 3 months ago
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Haskell data structure for maps and sets with partially ordered keys

• Host: GitHub
• URL: https://github.com/sgraf812/pomaps
• Owner: sgraf812
• License: other
• Created: 2017-08-17T15:07:04.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2021-02-07T20:05:58.000Z (almost 4 years ago)
• Last Synced: 2024-04-26T00:30:50.877Z (9 months ago)
• Language: Haskell
• Size: 324 KB
• Stars: 3
• Watchers: 5
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • License: LICENSE.md

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README

        
# [`pomaps`][pomaps] [![Build Status](https://github.com/sgraf812/pomaps/workflows/Haskell-CI/badge.svg)](https://github.com/sgraf812/pomaps/actions) [![Hackage](https://img.shields.io/hackage/v/pomaps.svg)](https://hackage.haskell.org/package/pomaps)

Reasonably fast maps (and possibly sets) based on keys satisfying [`PartialOrd`](https://hackage.haskell.org/package/lattices-1.6.0/docs/Algebra-PartialOrd.html#t:PartialOrd).

This package tries to load off as much work as possible to the excellent [`containers`](https://hackage.haskell.org/package/containers) library, in order to achieve acceptable performance.

The interface is kept as similar to [`Data.Map.{Strict,Lazy}`](https://hackage.haskell.org/package/containers/docs/Data-Map-Strict.html) as possible, which is an excuse for somewhat lacking documentation.

`POMap`s basically store a decomposition of totally ordered chains (e.g. something `Map`s can handle).

Functionality and strictness properties should be pretty much covered by the testsuite.

But it's not battle-tested yet, so if you encounter space leaks in the implementation, let me know.

A rather naive implementation leads to `O(w*n*log n)` lookups, where `w` is the width of the decomposition (which should be the size of the biggest anti-chain).

This is enough for me at the moment to get things going, but there is room for improvement ([Sorting and Selection in Posets](https://arxiv.org/abs/0707.1532)).

Let me know if things are too slow and I'll see what I can do!

[pomaps]: https://github.com/sgraf812/pomaps