On Thu, 26 Mar 2009, wren ng thornton wrote:
Functions like uncons and viewL are nicer (because they're safe), but they can have overhead because they're unnecessarily complete (e.g. the Maybe wrapper can be avoided if we know a-priori that Just will be the constructor used).
If you know, it's always Just, then don't use Maybe. There must be some point in your program, from where it is sure, that it is always Just and that is the point where to leave Maybe. When I searched my old code for fromJust and head and review it carefully, I could eliminate them in most cases.
In another thread (Grouping - Map/Reduce) there was a zipWithInf function which needed a lazy pattern match on (a:as). This indicates to me, that lists are the wrong data structure and it would be better to replace it by an always infinite list type with only one 'cons' constructor.
_______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
