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path empty #3420
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Activity
Should
Path("/")be considered empty, on unix? How aboutPath("C:\\")on windows? I'm asking because, to some extent, "empty" is a concept that doesn't really apply to paths-as-a-whole. Paths have components (which there might be zero of) plus possibly a root, of various forms.The structure holding Path is meant to be inspected directly if you like, so
p.components.len() == 0might tell you what you're interested in. Is that what you want to test though? Or only if it would literally evaluate to the empty string?I'd say the use case is the conversion of a string to a Path where the path is supposed to point to something that may or may not exist. These will often come from a config file or command line so there is a desire to do some preflighting or asserts to make sure that the path is sane. Perhaps the thing to do is provide some sort if is_well_formed method that checks for one or more components plus no bad characters for the current file system (WIndows, at least, has a lot of these).
Regardless I would like a more visible abstraction than checking that components is non-empty. Or alternatively just fail if from_str is called with something not well formed.
If from_str does fail there still needs to be a way for users to test paths so that they can error out gracefully, and error out early, instead of trundling along until the code finally tries to use the bad path.
non-critical for 0.6, de-milestoning
Do we want to have a notion of an "empty" path build into
Path, or should we useOption<Path>for this?I do not believe that we should support the notion of an empty
Path. We can already express this withOption<Path>. Thepathmodule treatsPath::new("")the same asPath::new(".")(for bothPosixPathandWindowsPath), and I think that's useful behavior.- added a commit that references this issue
on Mar 31, 2024
In porting my code over to the new Path struct(s) there are a number of places where I wanted to see if a path was set. For now I am using
str::is_not_empty(some_path.to_str()which I am not crazy about because it's going to allocate a string and, more importantly, because I'm not sure that ~"" will be round trippable for all file systems.Note that boost file system has an empty method for just this purpose.