On Thu, Dec 8, 2011 at 8:12 AM, Christoph Breitkopf <chbreitkopf@googlemail.com> wrote:

Hello,

I'm in the process of implementing a container data type, and wonder what class instances are generally considered necessary. E.g. is it ok to start out with a Show that's adequate for debugging, or is it a 'must' to include instances of everything possible (Eq, Ord if possible, Read, Show, Functor, ...).

Start out with Show and spend your time making sure that you're container type performs well (unless you're doing this as an exercise of course). A featureful API for something that's as slow as linked lists isn't very useful. ;)

-- Johan