Re: [Haskell-beginners] Map on Nested Lists

On 8 April 2010 14:37, Thomas Davie wrote:

You can't write a single such function to operate on all the different types, .... [SNIP]

Hi Bob (?) I believe Oleg Kiselyov's deepset functor manages it... http://okmij.org/ftp/Haskell/typecast.html http://okmij.org/ftp/Haskell/deepest-functor.lhs PS - is it Bob or Thomas? thanks. Best wishes Stephen