Add a write_char method to std::fmt::Formatter. #24689

SimonSapin · 2015-04-22T12:20:42Z

This is the logical next step after #24661, but I’m less sure about this one.

rust-highfive · 2015-04-22T12:20:55Z

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @alexcrichton (or someone else) soon.

If any changes to this PR are deemed necessary, please add them as extra commits. This ensures that the reviewer can see what has changed since they last reviewed the code. The way Github handles out-of-date commits, this should also make it reasonably obvious what issues have or haven't been addressed. Large or tricky changes may require several passes of review and changes.

Please see CONTRIBUTING.md for more information.

alexcrichton · 2015-04-28T17:25:41Z

Hm can you clarify why you'd want this as an inherent method? It seems like a similar win is gained from implementing fmt::Write. The main reason fmt::Write isn't leveraged for write_fmt is that it would require an import of a somewhat obscure trait in lots of code, but I think that write_char is pretty rare by comparison.

SimonSapin · 2015-04-28T20:13:30Z

I only made it an inherent method because write_str was as well, and this seemed like the smaller change. Note that Formatter currently does not implement any trait.

I don’t have a strong opinion on how to do this, or if it should be done at all.

alexcrichton · 2015-04-28T23:27:34Z

I think it would be safe to provide an implementation of the trait for Formatter, but I think we may want to hold off adding a method for now.

alexcrichton · 2015-06-10T18:04:44Z

@SimonSapin could you try adding this method through an implementation of the Write trait on the Formatter struct directly? I think it should have the implementation anyway and seems like a conservative way to expose the functionality.

This is the logical next step after rust-lang#24661, but I’m less sure about this one.

SimonSapin · 2015-06-10T19:42:32Z

Done. (Now the trait has to be in scope to use that method, of course.)

alexcrichton · 2015-06-10T20:00:00Z

src/libcore/fmt/mod.rs

@@ -892,6 +892,20 @@ impl<'a> Formatter<'a> {
    }
 }

+impl<'a> Write for Formatter<'a> {


Could you also tag this with #[stable(since = "1.2.0", ...)]?

alexcrichton · 2015-06-10T20:00:30Z

r=me with a stability tag, thanks @SimonSapin!

alexcrichton · 2015-06-10T20:06:47Z

@bors: r+ 63da18b

@alexcrichton

This is the logical next step after #24661, but I’m less sure about this one. r? @alexcrichton

bors · 2015-06-10T21:02:09Z

⌛ Testing commit 63da18b with merge db0c1cb...

bors · 2015-06-10T22:37:36Z

☀️ Test successful - auto-linux-32-nopt-t, auto-linux-32-opt, auto-linux-64-nopt-t, auto-linux-64-opt, auto-linux-64-x-android-t, auto-mac-32-opt, auto-mac-64-nopt-t, auto-mac-64-opt, auto-win-gnu-32-nopt-t, auto-win-gnu-32-opt, auto-win-gnu-64-nopt-t, auto-win-gnu-64-opt

SimonSapin · 2015-06-29T05:42:47Z

src/libcore/fmt/mod.rs

-        let mut utf8 = [0; 4];
-        let amt = self.encode_utf8(&mut utf8).unwrap_or(0);
-        let s: &str = unsafe { mem::transmute(&utf8[..amt]) };
-        Display::fmt(s, f)


Ah, yes, my mistake. Feel free to reverse this chunk if there isn’t a better solution.

This recently regressed in rust-lang#24689, and this updates the `Display` implementation to take formatting flags into account. Closes rust-lang#26625

This recently regressed in #24689, and this updates the `Display` implementation to take formatting flags into account. Closes #26625

This recently regressed in rust-lang#24689, and this updates the `Display` implementation to take formatting flags into account. Closes rust-lang#26625

rust-highfive assigned alexcrichton Apr 22, 2015

alexcrichton added T-libs-api Relevant to the library API team, which will review and decide on the PR/issue. I-needs-decision Issue: In need of a decision. labels May 26, 2015

alexcrichton removed the I-needs-decision Issue: In need of a decision. label Jun 10, 2015

Add a write_char method to std::fmt::Formatter.

15b028c

This is the logical next step after rust-lang#24661, but I’m less sure about this one.

SimonSapin force-pushed the formatter-write-char branch from b3c46d0 to 10fbce3 Compare June 10, 2015 19:42

alexcrichton reviewed Jun 10, 2015
View reviewed changes

Have std::fmt::Formatter implement std::fmt::Write.

63da18b

SimonSapin force-pushed the formatter-write-char branch from 10fbce3 to 63da18b Compare June 10, 2015 20:06

bors added a commit that referenced this pull request Jun 10, 2015

Auto merge of #24689 - SimonSapin:formatter-write-char, r=alexcrichton

db0c1cb

This is the logical next step after #24661, but I’m less sure about this one. r? @alexcrichton

bors merged commit 63da18b into rust-lang:master Jun 10, 2015

SimonSapin deleted the formatter-write-char branch June 10, 2015 22:57

BigBoneDaddy reviewed Jun 27, 2015
View reviewed changes

alexcrichton added a commit to alexcrichton/rust that referenced this pull request Jul 1, 2015

std: Fix formatting flags for chars

98566ea

This recently regressed in rust-lang#24689, and this updates the `Display` implementation to take formatting flags into account. Closes rust-lang#26625

alexcrichton mentioned this pull request Jul 1, 2015

std: Fix formatting flags for chars #26698

Merged

bors added a commit that referenced this pull request Jul 1, 2015

Auto merge of #26698 - alexcrichton:char-fmt, r=huonw

1fc0f68

This recently regressed in #24689, and this updates the `Display` implementation to take formatting flags into account. Closes #26625

alexcrichton added a commit to alexcrichton/rust that referenced this pull request Jul 8, 2015

std: Fix formatting flags for chars

8dff253

This recently regressed in rust-lang#24689, and this updates the `Display` implementation to take formatting flags into account. Closes rust-lang#26625

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Add a write_char method to std::fmt::Formatter. #24689

Add a write_char method to std::fmt::Formatter. #24689

SimonSapin commented Apr 22, 2015

rust-highfive commented Apr 22, 2015

alexcrichton commented Apr 28, 2015

SimonSapin commented Apr 28, 2015

alexcrichton commented Apr 28, 2015

alexcrichton commented Jun 10, 2015

SimonSapin commented Jun 10, 2015

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alexcrichton commented Jun 10, 2015

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bors commented Jun 10, 2015

SimonSapin Jun 29, 2015

Add a write_char method to std::fmt::Formatter. #24689

Add a write_char method to std::fmt::Formatter. #24689

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SimonSapin commented Apr 22, 2015

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