lens

This package provides families of lenses, isomorphisms, folds, traversals, getters and setters.

These lenses are compatible with those from lens-family, lens-family-core and lens-family-th, but they provide a great deal of additional flexibility in their composition.

An overview of the derivation of setters, folds, traversals, getters and lenses can be found on the lens wiki under Tutorial.

Example

ghci> :m + Control.Lens Data.Text.Lens
ghci> anyOf (traverse.text) (=='y') ["hello"^.packed, "goodbye"^.packed]
True

Contact Information

Contributions and bug reports are welcome!

Please feel free to contact me through github or on the #haskell IRC channel on irc.freenode.net.

-Edward Kmett