Thu, 29 Nov 2001 10:18:30 -0000
> A quick look at the source looks like both GHC and NHC will=20
> simply pass
> on errors from the OS, so for example with
> module Main where
> import IO
> import Directory
> main :: IO()
> main =3D do catch (createDirectory "this/does/not/exist/foo")
> (\e -> putStrLn $ show $ map (flip ($) e) errors)
> errors :: [(IOError -> Bool)]
> errors =3D [isDoesNotExistError,
> both GHC and NHC give [True,False,False,False] (I don't seem to have a
> hugs Directory.hs) while the library report only allows
> isIllegalOperation, isPermissionError and isAlreadyExistsError. I
> haven't looked for other cases of this.
Two possibilities: either createDirectory should act like 'mkdir -p' and
make the whole path, or the library report should document
isDoesNotExistError as a possible error thrown by createDirectory. I'd
vote for the latter.
No doubt there are many other cases of this, we should really do a full
audit of the I/O library specs.