Rust: Tracking issue for String::splice

[dtolnay]

RFC: https://github.com/rust-lang/rfcs/pull/1432

This was originally tracked in #32310 as a combination of Vec::splice and String::splice, but the libs team decided to stabilize Vec::splice while keeping String::splice unstable and changing its signature in #44038.

The new signature has been implemented in #44044 but needs to go through FCP.

impl String {
    pub fn splice<R>(&mut self, range: R, replace_with: &str)
        where R: RangeArgument<usize>;
}

[SimonSapin]

Ping @rust-lang/libs. FCP to stabilize?

[dtolnay]

I pushed for changing the signature so I will take responsibility for it. 😸

@rfcbot fcp merge

[rfcbot]

Team member @dtolnay has proposed to merge this. The next step is review by the rest of the tagged teams:

• [x] @BurntSushi
• [x] @Kimundi
• [x] @alexcrichton
• [x] @aturon
• [x] @dtolnay
• [x] @sfackler

No concerns currently listed.

Once these reviewers reach consensus, 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!

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[kennytm]

As I mentioned in https://github.com/rust-lang/rust/issues/32310#issuecomment-324406220, I'm :-1: to this if the method is called splice() as it does not return the deleted part, unlike Vec::splice(). Calling it replace_slice() seems more appropriate.

(

• C++ calls this replace,
• D calls this replaceInPlace,
• Java calls this replace
• Swift calls this replaceSubrange(_:with:).

Other languages either provides the IndexAssign operator x[range] = replace_with (e.g. Ruby, Perl), doesn't have a method for this (e.g. C#), or doesn't have mutable string (e.g. Python, JavaScript, Go).

We already used replace() for something else, so we can't name it replace() unless we have RangeArgument<usize> extends Pattern.

)

[SimonSapin]

replace_range?

[sfackler]

I like replace_range.

[rfcbot]

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

[rfcbot]

The final comment period is now complete.

[SimonSapin]

Help wanted: stabilization PR that also renames to replace_range.