https://github.com/purescript-contrib/purescript-profunctor-lenses
Pure profunctor lenses
https://github.com/purescript-contrib/purescript-profunctor-lenses
Last synced: about 1 month ago
JSON representation
Pure profunctor lenses
- Host: GitHub
- URL: https://github.com/purescript-contrib/purescript-profunctor-lenses
- Owner: purescript-contrib
- License: mit
- Created: 2015-09-06T00:50:25.000Z (over 9 years ago)
- Default Branch: main
- Last Pushed: 2024-09-18T23:03:12.000Z (7 months ago)
- Last Synced: 2025-03-01T04:16:17.587Z (about 2 months ago)
- Language: PureScript
- Homepage:
- Size: 260 KB
- Stars: 144
- Watchers: 8
- Forks: 52
- Open Issues: 20
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
Awesome Lists containing this project
- awesome-purescript - profunctor-lenses - A mechanism for updating, viewing, and setting values within nested data structures. (Lenses)
README
# Profunctor Lenses
[](https://github.com/purescript-contrib/purescript-profunctor-lenses/actions?query=workflow%3ACI+branch%3Amain)
[](https://github.com/purescript-contrib/purescript-profunctor-lenses/releases)
[](https://pursuit.purescript.org/packages/purescript-profunctor-lenses)
[](https://github.com/garyb)
Pure profunctor lenses: a mechanism for updating, viewing, and setting values within nested data structures.
Learn more about profunctor lenses with:
- [Practical Profunctor Optics & Lenses in PureScript](https://thomashoneyman.com/articles/practical-profunctor-lenses-optics/), a practical introduction to profunctor optics in PureScript
- [Lenses for the Mere Mortal](https://leanpub.com/lenses), a book about lenses in PureScript
## Installation
Install `profunctor-lenses` with [Spago](https://github.com/purescript/spago):
```sh
spago install profunctor-lenses
```
## Quick start
```purescript
> structure = Tuple (Tuple (Tuple "hi!" 3) 2) 1
> import Data.Lens
> _leftmost = _1 <<< _1 <<< _1
> view _leftmost structure
"hi!"
> set _leftmost "Bye!" structure
(Tuple (Tuple (Tuple "Bye!" 3) 2) 1)
> over _leftmost String.toUpper structure
(Tuple (Tuple (Tuple "HI!" 3) 2) 1)
```
You can try out the [examples](./examples) in the REPL by running:
```
spago -x examples.dhall repl
```
## Documentation
`profunctor-lenses` documentation is stored in a few places:
1. Module documentation is [published on Pursuit](https://pursuit.purescript.org/packages/purescript-profunctor-lenses).
1. Usage examples can be found in [the test suite](./test) and [`examples`](./examples) directory.
1. [Practical Profunctor Optics & Lenses in PureScript](https://thomashoneyman.com/articles/practical-profunctor-lenses-optics/), a practical introduction to profunctor optics in PureScript
1. [Lenses for the Mere Mortal](https://leanpub.com/lenses), a book about lenses in PureScript
If you get stuck, there are several ways to get help:
- [Open an issue](https://github.com/purescript-contrib/purescript-profunctor-lenses/issues) if you have encountered a bug or problem.
- Ask general questions on the [PureScript Discourse](https://discourse.purescript.org) forum or the [PureScript Discord](https://purescript.org/chat) chat.
## Contributing
You can contribute to `profunctor-lenses` in several ways:
1. If you encounter a problem or have a question, please [open an issue](https://github.com/purescript-contrib/purescript-profunctor-lenses/issues). We'll do our best to work with you to resolve or answer it.
1. If you would like to contribute code, tests, or documentation, please [read the contributor guide](./CONTRIBUTING.md). It's a short, helpful introduction to contributing to this library, including development instructions.
1. If you have written a library, tutorial, guide, or other resource based on this package, please share it on the [PureScript Discourse](https://discourse.purescript.org)! Writing libraries and learning resources are a great way to help this library succeed.