Pointless Lenses library

Pointless Lenses

This cabal package can be installed with:

$ cabal install pointless-lenses

For a manual install, execute:

$ runhaskell Setup.lhs configure $ runhaskell Setup.lhs build $ runhaskell Setup.lhs install

You can now start playing with the example code that comes with the library, under Language.Pointless.Examples.Examples. The easiest way is to create a new module that imports some library modules

module Test where

import Test.QuickCheck.Test import Generics.Pointless.Lenses import Generics.Pointless.Lenses.Examples.Examples

and interpret it

$ ghci Test.hs

We can now test the well-behavedness of some lens, for example:

quickCheck (wb filter_left_lns) +++ OK, passed 100 tests.

Or run some example and later check what it is actually doing:

put filter_left_lns ([1,2,3],[Left 0,Right 'a',Left 4]) [Left 1,Right 'a',Left 2,Left 3]