Re: [Haskell-cafe] inv f g = f . g . f

On Sat, Aug 17, 2013 at 11:11:07AM +0200, Christopher Done wrote:

Anyone ever needed this? Me and John Wiegley were discussing a decent name for it, John suggested inv as in involution. E.g.

inv reverse (take 10) inv reverse (dropWhile isDigit) trim = inv reverse (dropWhile isSpace) . dropWhile isSpace

This sounds like a job for a lens, or similar. Tom