2009/6/22 Duncan Coutts <duncan.cou...@worc.ox.ac.uk>: > On Mon, 2009-06-22 at 08:53 +0200, Deniz Dogan wrote: >> 2009/6/22 Colin Paul Adams <co...@colina.demon.co.uk>: >> >>>>>> "Judah" == Judah Jacobson <judah.jacob...@gmail.com> writes: >> > >> > Judah> On Sun, Jun 21, 2009 at 11:12 PM, Colin Paul >> > Judah> Adams<co...@colina.demon.co.uk> wrote: >> > >> I've been hoogling like bad to try to determine if a function >> > >> like this exists. >> > >> >> > >> getDirectoryContents returns sub-directories as well as file >> > >> names. I want only the latter, so I'm looking for a suitable >> > >> filter. >> > >> > Judah> Use System.Directory.doesDirectoryExist/doesFileExist. >> > >> > Thanks. >> > >> > it seems it's time i went to the optician again. >> >> I'm not surprised that anyone would make the mistake. I think that the >> two functions should be named "isDirectory" and "isFile", but it seems >> that "isDirectory" was already taken by another function in >> System.Directory, which is quite unfortunate. "does" goes against the >> intuition one gets from pretty much everything else in Haskell, where >> "is" seems to be the convention. In fact, Hoogle only knows about >> three functions which start with "does". > > One explanation is that isBlah asks "is this thing a blah", but we're > not asking that because there is an indirection via the filepath. We're > asking "does this filepath refer to a directory" not "is this filename a > directory". The latter could be a function: > > isDirectory :: FileInfo -> Bool > > along with a hypothetical > > getFileInfo :: FilePath -> IO FileInfo > > Duncan > >
I think see what you mean, but I find the argument more of an excuse to the poor naming than a solid argument for it. Following the convention and intuition that most users have should be more important than making the (sometimes unnecessary) distinction between a directory and the path to it. -- Deniz Dogan _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe