On Wed, Jun 13, 2007 at 11:48:18AM +0200, apfelmus wrote:
Hello,
inits [] = [[]] inits (x:xs) = [[]] ++ map (x:) (inits xs)
as specified in Data.List has a "semantic bug", namely it's too strict:
inits (1:_|_) = []:_|_
as opposed to the expected
inits (1:_|_) = []:[1]:_|_
A correct version would be
inits xs = []:case xs of [] -> [] (x:xs) -> map (x:) (inits xs)
The Haskell report specifies how inits has to behave, so this is a problem in the report, not in a concrete implementation. Where can I report a bug report for the report? ;)
http://haskell.org/haskellwiki/Language_and_library_specification says: The report still has minor bugs. There are tracked at the Haskell 98 bugs page. Report any new bugs to Malcolm Wallace. Stefan