lens-4.7.0.1: Lenses, Folds and Traversals

Copyright(C) 2012-14 Edward Kmett
LicenseBSD-style (see the file LICENSE)
MaintainerEdward Kmett <ekmett@gmail.com>
Stabilityprovisional
Portabilityportable
Safe HaskellSafe-Inferred
LanguageHaskell98

Control.Lens.Extras

Description

A few extra names that didn't make it into Control.Lens.

Synopsis

Documentation

is :: APrism s t a b -> s -> Bool

Check to see if this Prism matches.

>>> is _Left (Right 12)
False
>>> is hex "3f79"
True