Aaron Denney
What about splitFileExt "foo.bar."? ("foo", "bar.") or ("foo.bar.", "")?
The latter makes more sense to me, as an extension of the first case you give and splitting "foo.tar.gz" to ("foo.tar", "gz").
It's not that obvious: both choices are compatible with these. The former is produced by rules: - split the filename before the last dot *which is not the last character of the filename*, or at the end if there is no such dot - remove the first character of the extension if it's non-empty (the character must have been a dot) The latter is produced by rules: - split the filename before the last dot, or at the end if there is no dot at all - *if the extension is a sole dot, append a dot to the basename* - remove the first character of the extension if it's non-empty (the character must have been a dot) Special filenames of "." and ".." are treated separately, before these rules apply. Both choices are inverted by the same joinFileExt, which inserts a dot between the name and extension unless the extension is empty. These rules agree on "foo", "foo." and "foo.tar.gz", yet disagree on "foo.bar."; I don't know which is more natural. The difference influences the behavior of changeFileExt. These cases are the same with both choices: changeFileExt "foo.bar" "" = "foo" changeFileExt "foo.tar.gz" "" = "foo.tar" changeFileExt "foo." "" = "foo." changeFileExt "foo." "baz" = "foo..baz" but these differ - first choice: changeFileExt "foo.bar." "" = "foo" changeFileExt "foo.bar." "baz" = "foo.baz" or the second: changeFileExt "foo.bar." "" = "foo.bar." changeFileExt "foo.bar." "baz" = "foo.bar..baz" ? -- __("< Marcin Kowalczyk \__/ qrczak@knm.org.pl ^^ http://qrnik.knm.org.pl/~qrczak/