https://github.com/zwilias/elm-avl-dict-exploration

Alternative Dict implementation backed by an AVL tree
https://github.com/zwilias/elm-avl-dict-exploration

avl-tree dict elm

Last synced: about 2 months ago
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Alternative Dict implementation backed by an AVL tree

• Host: GitHub
• URL: https://github.com/zwilias/elm-avl-dict-exploration
• Owner: zwilias
• License: bsd-3-clause
• Created: 2017-02-26T09:03:12.000Z (almost 8 years ago)
• Default Branch: master
• Last Pushed: 2017-03-30T12:19:21.000Z (almost 8 years ago)
• Last Synced: 2024-10-13T02:21:45.869Z (3 months ago)
• Topics: avl-tree, dict, elm
• Language: Elm
• Homepage: http://package.elm-lang.org/packages/zwilias/elm-avl-dict-exploration/1.0.0
• Size: 355 KB
• Stars: 0
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Alternative Dict implementation backed by AVL tree [![Build Status](https://travis-ci.org/zwilias/elm-avl-dict-exploration.svg?branch=master)](https://travis-ci.org/zwilias/elm-avl-dict-exploration)

## Elevator pitch

Red-black trees as used in core's Dict require quite a few modifications for

rebalancing. Worse; they require quite a few comparisons to do the correct

modifications, which is notoriously slow in Elm. AVL trees offer similar

worst-case performance characteristics, but in this case, much better insertion

performance.

## Performance

You can find a little write up on the benchmarks and the methodology on [this page](http://elm-avl-dict-bench.surge.sh).

## Using Dict.AVL

`Dict.AVL` has the exact same API as core Dict, so using it can be accomplished

by simply doing something like this:

```elm

import Dict.AVL as Dict

```

There is one exception - checking for equality. Since core's Dict is special

cased in elm ecosystem for equality checks, and we can't use this same special

case due to a different internal structure, you'll need to use the

`Dict.AVL.eq` function.

```elm

import Dict.AVL as Dict

left = Dict.fromList [(0, ()), (1, ())]

right = Dict.fromList [(1, ()), (0, ())]

-- This will return False

left == right

-- This works as expected and returns True

Dict.eq left right

```