Add getDirectoryContents' which ignores "." and ".."

[guibou]

getDirectoryContents returns the "." and ".." special directories. However in most cases user do not care about theses values and must manually filter them. This pull request introduces the getDirectoryContents' variant which handle this filtering. I find this really convenient when working with directory listing. Other languages uses the same trick (such as python, with os.listdir(),

Discussion: should we update removeContentsRecursive to use getDirectoryContents' instead of the explicit manual filtering of "." and ".." ?

[Rufflewind]

Perhaps instead of using a prime (which may be confused for other things), we could call it getDirectoryContentsA to mirror the -A flag for ls. I was originally thinking of getDirectoryContentsPlain but the name is already too long.

should we update removeContentsRecursive to use getDirectoryContents' instead of the explicit manual filtering of "." and ".." ?

I don't see any reason not to :P

Thanks for the pull request!

[guibou]

Thank you for your reply. I will amend the pull request to change the name to getDirectoryContentsA, you are right that the prime is confusing, I initially saw it as an alternate version, but apparently it is commonly used for strict version of a function.

I also edited removeContentsRecursive to use the new getDirectoryContentsA. My last question is about the unit tests. For now there is 29 tests which introduce a use of getDirectoryContents (and a special handling of . and ..).

For the sake of simplifing the unit test, should we edit them to use getDirectoryContentsA in most cases ?

[guibou]

I amended the initial commit to change the name to getDirectoryContentsA, updated removeContentsRecursive to use it, and updated tests to use getDirectoryContentsA when it simplifies the tests.

[Rufflewind]

updated tests to use getDirectoryContentsA when it simplifies the tests.

While that's fine for the other tests, for tests/GetDirContents001.hs it's best to leave both getDirectoryContents and getDirectoryContentsA in to ensure that getDirectoryContents is covered by at least one test (to prevent a future change from accidentally removing . and .. from getDirectoryContents).

[guibou]

Thank you for merging it. Sorry I did not answer your complain about the unit test not covering . and .. for getDirectoryContents (I was busy this week...).

I'll soon do another pull request to fix that (an some other stuff if time is available).

[Rufflewind]

I'll soon do another pull request to fix that

Don't worry about that – it's all taken care of. Thanks for your contribution!

[Rufflewind]

Just a heads up in case you happen to be using HEAD: I've renamed getDirectoryContentsA to listDirectory.