suzanne.soy/lens
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Update README.md

Browse Source
This commit is contained in:
Jack Firth 2015-07-06 17:03:10 -07:00
parent 462f140c2e
commit a2ca938714
1 changed files with 3 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
README.md
View File

@ -2,4 +2,6 @@ lenses [![Build Status](https://travis-ci.org/jackfirth/lenses.svg?branch=master
===================================
[Documentation](http://pkg-build.racket-lang.org/doc/lenses/index.html)
A Racket package for creating and composing pure functional lenses. A lens is a function that examines a small subpiece of some larger structure. When given a value of that larger structure, the lens returns two values: a *view* value, which is the subpiece, and a *context* function, which accepts a new view value and returns a new structure with the old view replaced by the new view. Think of them as composable, pure functional getters and setters. Examples can be found in the documentation.
A Racket package for creating and composing pure functional lenses.
A lens is a value that can be used to focus on a small subpiece of some larger structure. Given a lens and a value of that larger structure, two values can be dervied: a *view* value, which is the subpiece, and a *context* function, which accepts a new view value and returns a new structure with the old view replaced by the new view. Think of them as composable, pure functional getters and setters. Examples can be found in the documentation.