Add some of `[T]`’s methods to strings and vice versa #1152

ftxqxd · 2015-06-06T02:33:16Z

Add some methods that already exist on slices to strings and vice versa. Specifically, the following methods should be added:

str::chunks
str::windows
str::into_string
String::into_boxed_slice
<[T]>::subslice_offset

Rendered

Kimundi · 2015-06-06T09:12:58Z

Is the reason for adding <[T]>::subslice_offset just symmetry? I'm asking because I'm not sure if that function is actually used by anyone.

ftxqxd · 2015-06-06T09:43:21Z

@Kimundi I’ve wanted to use it in the past, but yeah, it’s mainly just to match the str API. I wouldn’t really care if subslice_offset got removed from str (it’s not very useful), but I’d certainly prefer to either have it for both types or neither, rather than just one.

Gankra · 2015-06-06T15:34:02Z

Is there really a usecase for str::chunks or windows?

gkoz · 2015-06-06T15:41:56Z

Out of curiosity, what is Box<str> for? I haven't encountered any mentions of this type before.

Gankra · 2015-06-06T15:47:10Z

@gkoz In principle it's just a runtime-constructed &'static str (string litteral). one usize thinner than a String, but effectively immutable as a result.

ftxqxd · 2015-06-06T21:19:26Z

@gankro str::windows could be used to calculate the Sørensen–Dice coefficient of two strings, and str::chunks has been asked for on IRC a few times.

huonw · 2015-06-06T23:27:53Z

Hm, I suspect windows and chunks will encourage bad Unicode practice without a huge amount of benefit other than symmetry. Specifically they will split between combining characters.

SimonSapin · 2015-06-09T13:11:24Z

text/0000-slice-string-symmetry.md

“Character” is kinda ambiguous. (Unicode has four different definitions.) Maybe use chars instead?

krdln · 2015-06-09T14:38:35Z

+1 to functions involving Box<str>. I was surprised they weren't implemented. And it's good to lose those 4/8 bytes sometimes (especially when within an enum).

-1 to windows and chunks. I second @huonw that they encourage bad practices. I think they belong in unicode crate with codepoint_ and grapheme_ variants.

krdln · 2015-06-10T00:26:54Z

I just stumbled upon the lack of str::shift_char() counterpart for a slice. I guess it would also be worth adding.

ftxqxd · 2015-06-10T03:05:03Z

I just stumbled upon the lack of str::shift_char() counterpart for a slice. I guess it would also be worth adding.

@krdln #1058 already adds that, I believe.

comex · 2015-06-11T08:28:36Z

May be out of scope, but I'd like to see some form of find, rfind, replace, and other pattern-based methods added to [T] or Vec<T>. This would be useful, for example, when dealing with a &[u8] which represents a "string" that may not be valid UTF-8 (such as the contents of a Unix OsStr) - or just random binary data, for that matter.

Gankra · 2015-06-11T22:28:38Z

I concur with @huonw on the dubiousness of windows and chunks in the face of combining characters. It's not clear to me how the Sørensen–Dice coefficient is even supposed to interact with utf8 in that regard.

👍 on the Box conversions. Makes sense.

I'm completely indifferent on subslice_offset

alexcrichton · 2015-06-16T22:00:10Z

This RFC is now entering its final comment period.

alexcrichton · 2015-06-16T22:32:44Z

text/0000-slice-string-symmetry.md

I would personally prefer to not add this method to slices just yet, I suspect it won't survive stabilization of strings.

alexcrichton · 2015-06-16T22:34:17Z

I also agree with @huonw about being hesitant to add windows/chunks to strings due to unicode fun stuff.

nagisa · 2015-06-17T08:37:57Z

text/0000-slice-string-symmetry.md

https://github.com/rust-lang/rfcs/pull/1152/files#r32605082 ditto.

sfackler · 2015-06-21T23:19:33Z

The Box<str> methods seem good to me but I share the unicode weirdness concerns above with respect to chunks and windows and am not sold on the utility of subslice_offset.

Gankra · 2015-06-22T01:16:49Z

@P1start the libs team seems pretty unanimous about Box<str> is great, everything else is not. Is this an acceptable result of this RFC, for you?

ftxqxd · 2015-06-22T03:34:55Z

@gankro Yep, that’s fine by me. I’ll update the RFC soon to include just those methods (and rename into_boxed_slice to into_boxed_str unless anyone has any objections).

ftxqxd · 2015-06-27T03:59:42Z

RFC updated, removing str::windows, str::chunks, and <[T]>::subslice_offset.

alexcrichton · 2015-07-01T02:09:57Z

The consensus of the libs team is to merge this RFC, so I will do so. Thanks again @P1start!

aturon · 2015-07-01T23:59:27Z

Tracking issue.

This is the name that was decided in rust-lang/rfcs#1152, and it's better if we say “boxed str” for `Box<str>`. The old name `String::into_boxed_slice` is deprecated.

Rename String::into_boxed_slice -> into_boxed_str This is the name that was decided in rust-lang/rfcs#1152, and it's better if we say “boxed str” for `Box<str>`. The old name `String::into_boxed_slice` is deprecated.

Add some of [T]’s methods to str and vice versa

e4372c4

alexcrichton added the T-libs-api Relevant to the library API team, which will review and decide on the RFC. label Jun 6, 2015

SimonSapin reviewed Jun 9, 2015
View reviewed changes

Gankra self-assigned this Jun 11, 2015

alexcrichton added the final-comment-period Will be merged/postponed/closed in ~10 calendar days unless new substational objections are raised. label Jun 16, 2015

alexcrichton reviewed Jun 16, 2015
View reviewed changes

nagisa reviewed Jun 17, 2015
View reviewed changes

text/0000-slice-string-symmetry.md Outdated

Copy link

Member

nagisa Jun 17, 2015

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

https://github.com/rust-lang/rfcs/pull/1152/files#r32605082 ditto.

Remove str::{windows,chunks} and <[T]>::subslice_offset

566bb70

alexcrichton mentioned this pull request Jul 1, 2015

Add conversions from Box<str> and String rust-lang/rust#26697

Closed

alexcrichton merged commit 566bb70 into rust-lang:master Jul 1, 2015

aturon mentioned this pull request Jul 1, 2015

Tracking issue for Add some of [T]’s methods to strings and vice versa (RFC 1152) rust-lang/rust#26729

Closed

bluss mentioned this pull request Aug 12, 2015

Rename String::into_boxed_slice -> into_boxed_str rust-lang/rust#27696

Merged

Centril unassigned Gankra Nov 23, 2018

Centril added the A-slice Slice related proposals & ideas label Nov 23, 2018

Add some of [T]’s methods to strings and vice versa #1152

Add some of [T]’s methods to strings and vice versa #1152

Uh oh!

Conversation

ftxqxd commented Jun 6, 2015

Uh oh!

Kimundi commented Jun 6, 2015

Uh oh!

ftxqxd commented Jun 6, 2015

Uh oh!

Gankra commented Jun 6, 2015

Uh oh!

gkoz commented Jun 6, 2015

Uh oh!

Gankra commented Jun 6, 2015

Uh oh!

ftxqxd commented Jun 6, 2015

Uh oh!

huonw commented Jun 6, 2015

Uh oh!

SimonSapin Jun 9, 2015

Choose a reason for hiding this comment

Uh oh!

krdln commented Jun 9, 2015

Uh oh!

krdln commented Jun 10, 2015

Uh oh!

ftxqxd commented Jun 10, 2015

Uh oh!

comex commented Jun 11, 2015

Uh oh!

Gankra commented Jun 11, 2015

Uh oh!

alexcrichton commented Jun 16, 2015

Uh oh!

alexcrichton Jun 16, 2015

Choose a reason for hiding this comment

Uh oh!

alexcrichton commented Jun 16, 2015

Uh oh!

nagisa Jun 17, 2015

Choose a reason for hiding this comment

Uh oh!

sfackler commented Jun 21, 2015

Uh oh!

Gankra commented Jun 22, 2015

Uh oh!

ftxqxd commented Jun 22, 2015

Uh oh!

ftxqxd commented Jun 27, 2015

Uh oh!

alexcrichton commented Jul 1, 2015

Uh oh!

aturon commented Jul 1, 2015

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

13 participants

Add some of `[T]`’s methods to strings and vice versa #1152

Add some of `[T]`’s methods to strings and vice versa #1152