Tracking Issue for ASCII methods on OsStr

[TyPR124]

Feature gate: #![feature(osstring_ascii)]

Public API

impl OsStr {
    pub fn make_ascii_lowercase(&mut self);
    pub fn make_ascii_uppercase(&mut self);
    pub fn to_ascii_lowercase(&self) -> OsString;
    pub fn to_ascii_uppercase(&self) -> OsString;
    pub fn is_ascii(&self) -> bool;
    pub fn eq_ignore_ascii_case<S: AsRef<OsStr>>(&self, other: S) -> bool;
}

Steps / History

• Allow obtaining &mut OsStr #70048 - Stabilized traits necessary to obtain &mut OsStr
• ASCII methods on OsStr #69937 - Added ASCII methods on OsStr
• Final commenting period (FCP)
• stabilize feature(osstring_ascii) #80193 - Stabilization PR

Unresolved Questions

• None yet.

[matklad]

Just needed OsStr::to_ascii_lowercase to manipulate paths on windows -- I need to lower case driver letter, C:\Program Files -> c:\Program Files.

[jplatte]

Currently, SQLx contains

env::var("SQLX_OFFLINE")
    .map(|s| s.eq_ignore_ascii_case("true") || s == "1")
    .unwrap_or(false)

The UTF-8 check that is included in there, while not a problem in practice, seems pointless. Changing to var_os lands me here because of the eq_ignore_ascii_case. Also, if somebody did a similar thing with .ok() instead of .unwrap_or(...), the var_os version could drop that and would then be a bit less noisy.

[tesuji]

#80193 is a stabilization PR.
Since lib team wants to do fcp in the tracking issue. @m-ou-se could you start one ?

[m-ou-se]

@rfcbot merge

[rfcbot]

Team member @m-ou-se has proposed to merge this. The next step is review by the rest of the tagged team members:

• @Amanieu
• @BurntSushi
• @KodrAus
• @dtolnay
• @m-ou-se
• @sfackler

Concerns:

• eq_ignore_ascii_case &S resolved by Tracking Issue for ASCII methods on OsStr #70516 (comment)

Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!

See this document for info about what commands tagged team members can give me.

[dtolnay]

Slight question about eq_ignore_ascii_case -- normally when dealing with AsRef args, they come in without an explicit reference in the signature (https://doc.rust-lang.org/std/process/struct.Command.html#method.new), except when necessary to support a lifetime in the return value (https://doc.rust-lang.org/std/path/struct.Path.html#method.new). Currently https://doc.rust-lang.org/1.49.0/std/ffi/struct.OsStr.html#method.eq_ignore_ascii_case is declared as:

pub fn eq_ignore_ascii_case<S: ?Sized + AsRef<OsStr>>(&self, other: &S) -> bool

Is this supposed to be fn eq_ignore_ascii_case<S: AsRef<OsStr>>(&self, other: S) -> bool instead?

@rfcbot concern eq_ignore_ascii_case &S

[TyPR124]

Is this supposed to be fn eq_ignore_ascii_case<S: AsRef<OsStr>>(&self, other: S) -> bool instead?

I think it should be. I'm not sure why I wrote it like I did originally, but this makes more sense to me.

I can make that PR if needed. Or can it be done in the stabilization PR? Not sure what the process is from here.

[dtolnay]

@rfcbot resolve eq_ignore_ascii_case &S
@rfcbot reviewed
Fixed in #81710.

[rfcbot]

🔔 This is now entering its final comment period, as per the review above. 🔔

[rfcbot]

The final comment period, with a disposition to merge, as per the review above, is now complete.

As the automated representative of the governance process, I would like to thank the author for their work and everyone else who contributed.

The RFC will be merged soon.

[fogti]

@TyPR124 you can tick the FCP box, as the FCP is complete.