Manipulating path segments

[SimonSapin]

Url currently has pop_path_segments and push_path_segment methods, but they have a design problem reported by @sfackler. A path is at minimum / which is considered like a single path segment that happens to be empty (like trailing slashes in general), so push_path_segment("foo") make the path be //foo with two slashes.

Fixing this may involve breaking API changes, so instead I’ll make these methods private (effectively removing them) before publishing 1.0.0, in order to unblock it. I’ll add them back (or something else to provide this functionality) in 1.1.0.

[sfackler]

In the meantime, what's the right way to add path segments? Something like

let mut url = ...;
url.set_path(&format!("{}/{}", url.path(), percent_encode(new_component.as_bytes(), PATH_SEGMENT_ENCODE_SET);

?

[sfackler]

I guess it would actually need to check if url.path() == "/" to avoid the empty path problem.

[SimonSapin]

Yes, something like that.

[mhristache]

I guess the current issue is related so I am posting here. Let me know if I should open a new issue.

I am trying to switch to url 1.0.0 but I cannot find the equivalent of the url 0.5 code below:

let mut path = url.path_mut().unwrap();
path.push(segment.to_owned());

I am trying to append a segment to a path which doesn't end with a trailing / and url.join() cannot handle this scenario. Is there a way to do this with url 1.0.0 or I need to do some ugly string concat to make sure a trailing / is always present and then use url.join()?

Thanks

[SimonSapin]

In 1.0.0 you have to use string concatenation and url.set_path(p). In 1.1.0 I want to add something like url.push_path_segment(s) (but maybe a different API) which would do the right thing in various situations.

[jgillich]

The example by @sfackler doens't appear to work, you'd have to create a String out of url.path() first, which is not great.

src/transport.rs:46:40: 46:43 error: cannot borrow `url` as immutable because it is also borrowed as mutable [E0502]
src/transport.rs:46         url.set_path(&format!("{}/{}", url.path(), path));
                                                           ^~~
<std macros>:2:26: 2:57 note: in this expansion of format_args!
src/transport.rs:46:23: 46:57 note: in this expansion of format! (defined in <std macros>)
src/transport.rs:46:9: 46:12 note: previous borrow of `url` occurs here; the mutable borrow prevents subsequent moves, borrows, or modification of `url` until the borrow ends
src/transport.rs:46         url.set_path(&format!("{}/{}", url.path(), path));
                            ^~~

[SimonSapin]

Yeah, for now you have to move the format!(…) expression into a separate variable.

The API I have in mind would be something like this:

impl Url {
    fn path_segments_mut(&mut self) -> PathSegmentsMut { … }
}
struct PathSegmentsMut<'a> {
    url: &'a mut Url
}
impl<'a> PathSegmentsMut<'a> {
    fn iter(&self) -> PathSegments { … }
    fn clear(&mut self) { … }
    fn pop(&mut self) { … }
    fn push(&mut self, s: &str) { … }
}