Haskell standard should get a strict foldl: either under some new standard name (foldl' is most common), or just replacing foldl. Is there a real-life case where a lazy foldl is desirable? I don't mean a constructed artificial example, I know they exist, but something which is really used. Currently usages of foldl fall into two major groups: those which are inlined and transformed into a strict foldl by an optimizing compiler, and those which have a space leak and a potential for stack overflow for large data. Even if there are cases where a lazy foldl is essential, I would prefer to have to code them with an explicit recursion, and reserve foldl for the more common cases where it should better be strict. -- __("< Marcin Kowalczyk \__/ qrczak@knm.org.pl ^^ http://qrnik.knm.org.pl/~qrczak/