Jeff King <peff@xxxxxxxx> writes: > On Thu, Jan 04, 2018 at 06:54:12PM -0500, Jeff King wrote: > >> > If we really want to be anal, perhaps a new helper path_exists() >> > that cares only about existence of paths (i.e. the implementation of >> > these two helpers they currently have), together with update to >> > check the st.st_mode for file_exists() and dir_exists(), may help >> > making the API set more rational, but I do not think it is worth it. >> >> Yep, I also considered that file_exists() probably wants to be >> path_exists() with its current implementation. We'd probably want to >> review all of the callers. >> >> Anyway, I tried to do the minimal refactoring here, with no change in >> behavior. I'm not opposed to calling this dir_exists() as path_exists() >> and making it globally available (as you note, I don't think we'd want >> to use a true dir_exists() here). > > So I actually started down this road just now, but I'm not sure if it's > worth it. Yeah, although I said it already without starting down this road, you actually thought about it more and your insight is more valuable ;-) > If we were to transition to an endgame with path_exists(), > dir_exists(), and file_exists(), we'd probably want to do something > like: > > 1. introduce path_exists(), but leave existing file_exists() callers > in place > > 2. introduce file_exists_as_file(), which checks S_IFREG > > 3. audit each file_exists() call to see if it ought to be > path_exists() or file_exists_as_file() and convert as needed > > 4. When there are no more file_exists() calls left, all > file_exists_as_file() instances can be renamed to file_exists(). > > But as with any "audit each..." plan, that leaves topics in flight out > of luck. If we want to be kind to those, we'd have to wait a long while > to shake out any file_exists() callers. > > At which point is there much value in having path_exists() as a wrapper? > It's a better name, perhaps, but I think my future-proofing against > "file_exists() may become file-specific" was probably overly paranoid. I > don't think we could sanely do that conversion without risking breakage. If we want to, the endgame can be to have a single path_exists_as() helper that could be used like so: #define PATH_TYPE_IFREG (1<<0) #define PATH_TYPE_IFLNK (1<<1) #define PATH_TYPE_IFDIR (1<<2) #define PATY_TYPE_IFANY ((1<<3)-1) #define path_exists(path) path_exists_as(path, PATH_TYPE_ANY) #define path_exists_as_file(path) path_exists_as(path, PATH_TYPE_IFREG) /* backward compatibility */ #define file_exists(path) path_exists_as(path, PATH_TYPE_ANY) We can avoid "file-exists used to mean this thing but in a distant future it means completely different thing" that way. > Maybe we should just document its behavior and use it here, rather than > introducing this new dir_exists(). Sounds good enough to me ;-)
