Recursive walks down a directory

[prcastro]

To work with directories, a nice function to have is walk. It would walk down a directory and its subdirectories, and return a generator. Each step would give the user the current path, the subdirectories in that path, and the files inside that path.

It's similar to the function walk on Python's os library:
https://docs.python.org/2/library/os.html#os.walk

[johnmyleswhite]

There are multiple implementations of this already floating around, including one in the FileFind package. The best way to move things forward is to do some work to clean up that package.

[StefanKarpinski]

I think at this point I would support having a walkdir function in base. It should be quite simple and general, of course.

[remusao]

Maybe we could get some inspiration from the os module of Python that has some handy function like the one you are looking for : os.walk. @johnmyleswhite, from what I understand you use a callback to use on each file found in the way, what about an iterator-way of doing this?

[johnmyleswhite]

Using an iterator could be cool. I'd just make sure you offer both DFS and BFS traversal of the directory tree.

And if we were indeed going to improve on the FileFind package, using a iterative method would also help in keeping track of symlink calls.

I think at this point I would support having a walkdir function in base. It should be quite simple and general, of course.

@StefanKarpinski, did you have anything specific in mind that you want to see avoided in a walkdir function in order to keep it simple and general?