https://github.com/bodil/purescript-sized-vectors

Idris style sized vectors in PureScript
https://github.com/bodil/purescript-sized-vectors

Last synced: about 1 month ago
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Idris style sized vectors in PureScript

• Host: GitHub
• URL: https://github.com/bodil/purescript-sized-vectors
• Owner: bodil
• Created: 2016-10-23T20:19:13.000Z (about 8 years ago)
• Default Branch: master
• Last Pushed: 2021-01-05T08:53:32.000Z (almost 4 years ago)
• Last Synced: 2024-09-12T04:41:01.833Z (2 months ago)
• Language: PureScript
• Size: 66.4 KB
• Stars: 18
• Watchers: 5
• Forks: 12
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md

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README

        
# purescript-sized-vectors

[![Build Status](https://travis-ci.org/bodil/purescript-sized-vectors.svg?branch=master)](https://travis-ci.org/bodil/purescript-sized-vectors)

Idris style sized vectors using [purescript-typelevel](https://github.com/bodil/purescript-typelevel).

- [API docs on Pursuit](http://pursuit.purescript.org/packages/purescript-sized-vectors/)

## Installation

```bash

bower install --save purescript-sized-vectors

```

or

```

spago install sized-vectors

```

## Usage

The sized vector datatype `(Nat s) ⇒ Vec s a` is implemented as a newtype wrapper around an `Array`, but has a known size `s` at the type level (which must be a type in `Data.Typelevel.Num.Nat`). Thus, the type checker is able to catch things like index out of bounds errors instead of forcing you to deal with `Maybe` values. Of course, this comes with its own set of limitations: operations where the size of a resulting vector can't be determined from the input types are impossible, an example being `filter`. However, you still have the full `Functor` - `Applicative` - `Monad` suite available, in addition to the `Foldable` and `Traversable` classes, and the full set of equivalents to `Array` operations allowed by `Vec`'s constraints. Note however that `apply`, `pure`, and `bind` do not work in the same way as they do with normal `Array`s, but instead make sure to keep the `Vec` lengths the same, leading to fully law-abiding instances.

You can construct `Vec`s in only two ways: through consing `1 +> 2 +> 3 +> empty` or through factory functions `singleton "a Vec of one single string"` and `replicate d5 "this string is repeated 5 times"`. Note the `d5` in the last example: `Vec` operations always take type level numbers where `Array` operations would take integer values.

## Releases

See [Changelog](CHANGELOG.md).

## LICENCE

Copyright 2016 Bodil Stokke

This program is free software: you can redistribute it and/or modify

it under the terms of the GNU Lesser General Public License as

published by the Free Software Foundation, either version 3 of the

License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but

WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public

License along with this program. If not, see

.