Update `?` repetition disambiguation. #49719

mark-i-m · 2018-04-06T00:55:36Z

Do not merge (yet)

This is a test implementation of some ideas from discussion in #48075 . This PR

disallows ? repetition from taking a separator, since the separator is never used.
disallows the use of ? as a separator. This allows patterns like $(a)?+ to match + and a+ rather than a?a?a. This is a breaking change, but maybe that's ok? Perhaps a crater run is the right approach?

cc @durka @alexreg @nikomatsakis

rust-highfive · 2018-04-06T00:55:39Z

r? @petrochenkov

(rust_highfive has picked a reviewer for you, use r? to override)

TimNN · 2018-04-06T02:16:20Z

Your PR failed on Travis. Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

Resolving deltas: 100% (612410/612410), completed with 4868 local objects.
---
[00:00:44] configure: rust.quiet-tests     := True
---
[00:39:37] ..........................................................................i.........................
[00:39:43] .................i..................................................................................
---
[00:40:18] ..................................................F...........................................i.....
[00:40:25] ....................................................................i...............................
---
[00:40:46] 1 error: `?` macro repetition does not allow a separator
[00:40:46] -   --> $DIR/macro-at-most-once-rep-ambig.rs:29:10
[00:40:46] +   --> $DIR/macro-at-most-once-rep-ambig.rs:22:10
[00:40:46] 3    |
[00:40:46] 4 LL |     ($(a),?) => {} //~ ERROR `?` macro repetition does not allow a separator
[00:40:46] 5    |          ^
[00:40:46]
[00:40:46] 6
[00:40:46] 7 error: no rules expected the token `?`
[00:40:46] -   --> $DIR/macro-at-most-once-rep-ambig.rs:43:11
[00:40:46] +   --> $DIR/macro-at-most-once-rep-ambig.rs:36:11
[00:40:46] 9    |
[00:40:46] 10 LL |     foo!(a?a?a); //~ ERROR no rules expected the token `?`
[00:40:46] 11    |           ^
[00:40:46]
[00:40:46] 12
[00:40:46] 13 error: no rules expected the token `?`
[00:40:46] -   --> $DIR/macro-at-most-once-rep-ambig.rs:44:11
[00:40:46] +   --> $DIR/macro-at-most-once-rep-ambig.rs:37:11
[00:40:46] 15    |
[00:40:46] 16 LL |     foo!(a?a); //~ ERROR no rules expected the token `?`
[00:40:46] 17    |           ^
[00:40:46]
[00:40:46] 18
[00:40:46] 19 error: no rules expected the token `?`
[00:40:46] -   --> $DIR/macro-at-most-once-rep-ambig.rs:45:11
[00:40:46] +   --> $DIR/macro-at-most-once-rep-ambig.rs:38:11
[00:40:46] 21    |
[00:40:46] 22 LL |     foo!(a?); //~ ERROR no rules expected the token `?`
[00:40:46] 23    |           ^
[00:40:46]
[00:40:46] 24
[00:40:46] 25 error: unexpected end of macro invocation
[00:40:46] -   --> $DIR/macro-at-most-once-rep-ambig.rs:46:5
[00:40:46] +   --> $DIR/macro-at-most-once-rep-ambig.rs:39:5
[00:40:46] 27    |
[00:40:46] 28 LL |     barplus!(); //~ ERROR unexpected end of macro invocation
[00:40:46] 29    |     ^^^^^^^^^^^
[00:40:46]
[00:40:46] 30
[00:40:46] 31 error: unexpected end of macro invocation
[00:40:46] -   --> $DIR/macro-at-most-once-rep-ambig.rs:47:5
[00:40:46] +   --> $DIR/macro-at-most-once-rep-ambig.rs:40:5
[00:40:46] 33    |
[00:40:46] 34 LL |     barstar!(); //~ ERROR unexpected end of macro invocation
[00:40:46] 35    |     ^^^^^^^^^^^
[00:40:46]
[00:40:46] 36
[00:40:46] 37 error: no rules expected the token `?`
[00:40:46] -   --> $DIR/macro-at-most-once-rep-ambig.rs:48:15
[00:40:46] +   --> $DIR/macro-at-most-once-rep-ambig.rs:41:15
[00:40:46] 39    |
[00:40:46] 40 LL |     barplus!(a?); //~ ERROR no rules expected the token `?`
[00:40:46] 41    |               ^
[00:40:46]
[00:40:46] 42
[00:40:46] 43 error: unexpected end of macro invocation
[00:40:46] -   --> $DIR/macro-at-most-once-rep-ambig.rs:49:14
[00:40:46] +   --> $DIR/macro-at-most-once-rep-ambig.rs:42:14
[00:40:46] 45    |
[00:40:46] 46 LL |     barplus!(a); //~ ERROR unexpected end of macro invocation
[00:40:46] 47    |              ^
[00:40:46]
[00:40:46] 48
[00:40:46] 49 error: no rules expected the token `?`
[00:40:46] -   --> $DIR/macro-at-most-once-rep-ambig.rs:50:15
[00:40:46] +   --> $DIR/macro-at-most-once-rep-ambig.rs:43:15
[00:40:46] 51    |
[00:40:46] 52 LL |     barstar!(a?); //~ ERROR no rules expected the token `?`
[00:40:46] 53    |               ^
[00:40:46]
[00:40:46] 54
[00:40:46] 55 error: unexpected end of macro invocation
[00:40:46] -   --> $DIR/macro-at-most-once-rep-ambig.rs:51:14
[00:40:46] +   --> $DIR/macro-at-most-once-rep-ambig.rs:44:14
[00:40:46] 57    |
[00:40:46] 58 LL |     barstar!(a); //~ ERROR unexpected end of macro invocation
[00:40:46] 59    |              ^
[00:40:46]
[00:40:46] 60
[00:40:46] - error: aborting due to 10 previous errors
[00:40:46] + error: unexpected end of macro invocation
[00:40:46] +   --> $DIR/macro-at-most-once-rep-ambig.rs:47:14
[00:40:46] +    |
[00:40:46] + LL |     barplus!(a); // ok
[00:40:46] +    |              ^
---
[00:40:46] /checkout/src/test/ui/update-references.sh '/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui' 'macros/macro-at-most-once-rep-ambig.rs'
[00:40:46]
[00:40:46] error: 1 errors occurred comparing output.
[00:40:46] status: exit code: 101
[00:40:46] command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/ui/macros/macro-at-most-once-rep-ambig.rs" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "-Zui-testing" "-C" "prefer-dynamic" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/macros/macro-at-most-once-rep-ambig.stage2-x86_64-unknown-linux-gnu" "-Crpath" "-O" "-Zmiri" "-Zunstable-options" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/macros/macro-at-most-once-rep-ambig.stage2-x86_64-unknown-linux-gnu.aux" "-A" "unused"
---
[00:40:46] {"message":"`?` macro repetition does not allow a separator","code":null,"level":"error","spans":[{"file_name":"/checkout/src/test/ui/macros/macro-at-most-once-rep-ambig.rs","byte_start":780,"byte_end":781,"line_start":22,"line_end":22,"column_start":10,"column_end":11,"is_primary":true,"text":[{"text":"    ($(a),?) => {} //~ ERROR `?` macro repetition does not allow a separator","highlight_start":10,"highlight_end":11}],"label":null,"suggested_replacement":null,"expansion":null}],"children":[],"rendered":"error: `?` macro repetition does not allow a separator\n  --> /checkout/src/test/ui/macros/macro-at-most-once-rep-ambig.rs:22:10\n   |\nLL |     ($(a),?) => {} //~ ERROR `?` macro repetition does not allow a separator\n   |          ^\n\n"}
[00:40:46] {"message":"no rules expected the token `?`","code":null,"level":"error","spans":[{"file_name":"/checkout/src/test/ui/macros/macro-at-most-once-rep-ambig.rs","byte_start":1025,"byte_end":1026,"line_start":36,"line_end":36,"column_start":11,"column_end":12,"is_primary":true,"text":[{"text":"    foo!(a?a?a); //~ ERROR no rules expected the token `?`","highlight_start":11,"highlight_end":12}],"label":null,"suggested_replacement":null,"expansion":null}],"children":[],"rendered":"error: no rules expected the token `?`\n  --> /checkout/src/test/ui/macros/macro-at-most-once-rep-ambig.rs:36:11\n   |\nLL |     foo!(a?a?a); //~ ERROR no rules expected the token `?`\n   |           ^\n\n"}
[00:40:46] {"message":"no rules expected the token `?`","code":null,"level":"error","spans":[{"file_name":"/checkout/src/test/ui/macros/macro-at-most-once-rep-ambig.rs","byte_start":1084,"byte_end":1085,"line_start":37,"line_end":37,"column_start":11,"column_end":12,"is_primary":true,"text":[{"text":"    foo!(a?a); //~ ERROR no rules expected the token `?`","highlight_start":11,"highlight_end":12}],"label":null,"suggested_replacement":null,"expansion":null}],"children":[],"rendered":"error: no rules expected the token `?`\n  --> /checkout/src/test/ui/macros/macro-at-most-once-rep-ambig.rs:37:11\n   |\nLL |     foo!(a?a); //~ ERROR no rules expected the token `?`\n   |           ^\n\n"}
[00:40:46] {"message":"no rules expected the token `?`","code":null,"level":"error","spans":[{"file_name":"/checkout/src/test/ui/macros/macro-at-most-once-rep-ambig.rs","byte_start":1141,"byte_end":1142,"line_start":38,"line_end":38,"column_start":11,"column_end":12,"is_primary":true,"text":[{"text":"    foo!(a?); //~ ERROR no rules expected the token `?`","highlight_start":11,"highlight_end":12}],"label":null,"suggested_replacement":null,"expansion":null}],"children":[],"rendered":"error: no rules expected the token `?`\n  --> /checkout/src/test/ui/macros/macro-at-most-once-rep-ambig.rs:38:11\n   |\nLL |     foo!(a?); //~ ERROR no rules expected the token `?`\n   |           ^\n\n"}
[00:40:46] {"message":"unexpected end of macro invocation","code":null,"level":"error","spans":[{"file_name":"/checkout/src/test/ui/macros/macro-at-most-once-rep-ambig.rs","byte_start":1191,"byte_end":1202,"line_start":39,"line_end":39,"column_start":5,"column_end":16,"is_primary":true,"text":[{"text":"    barplus!(); //~ ERROR unexpected end of macro invocation","highlight_start":5,"highlight_end":16}],"label":null,"suggested_replacement":null,"expansion":null}],"children":[],"rendered":"error: unexpected end of macro invocation\n  --> /checkout/src/test/ui/macros/macro-at-most-once-rep-ambig.rs:39:5\n   |\nLL |     barplus!(); //~ ERROR unexpected end of macro invocation\n   |     ^^^^^^^^^^^\n\n"}
[00:40:46] {"message":"unexpected end of macro invocation","code":null,"level":"error","spans":[{"file_name":"/checkout/src/test/ui/macros/macro-at-most-once-rep-ambig.rs","byte_start":1252,"byte_end":1263,"line_start":40,"line_end":40,"column_start":5,"column_end":16,"is_primary":true,"text":[{"text":"    barstar!(); //~ ERROR unexpected end of macro invocation","highlight_start":5,"highlight_end":16}],"label":null,"suggested_replacement":null,"expansion":null}],"children":[],"rendered":"error: unexpected end of macro invocation\n  --> /checkout/src/test/ui/macros/macro-at-most-once-rep-ambig.rs:40:5\n   |\nLL |     barstar!(); //~ ERROR unexpected end of macro invocation\n   |     ^^^^^^^^^^^\n\n"}
[00:40:46] {"message":"no rules expected the token `?`","code":null,"level":"error","spans":[{"file_name":"/checkout/src/test/ui/macros/macro-at-most-once-rep-ambig.rs","byte_start":1323,"byte_end":1324,"line_start":41,"line_end":41,"column_start":15,"column_end":16,"is_primary":true,"text":[{"text":"    barplus!(a?); //~ ERROR no rules expected the token `?`","highlight_start":15,"highlight_end":16}],"label":null,"suggested_replacement":null,"expansion":null}],"children":[],"rendered":"error: no rules expected the token `?`\n  --> /checkout/src/test/ui/macros/macro-at-most-once-rep-ambig.rs:41:15\n   |\nLL |     barplus!(a?); //~ ERROR no rules expected the token `?`\n   |               ^\n\n"}
[00:40:46] {"message":"unexpected end of macro invocation","code":null,"level":"error","spans":[{"file_name":"/checkout/src/test/ui/macros/macro-at-most-once-rep-ambig.rs","byte_start":1382,"byte_end":1383,"line_start":42,"line_end":42,"column_start":14,"column_end":15,"is_primary":true,"text":[{"text":"    barplus!(a); //~ ERROR unexpected end of macro invocation","highlight_start":14,"highlight_end":15}],"label":null,"suggested_replacement":null,"expansion":null}],"children":[],"rendered":"error: unexpected end of macro invocation\n  --> /checkout/src/test/ui/macros/macro-at-most-once-rep-ambig.rs:42:14\n   |\nLL |     barplus!(a); //~ ERROR unexpected end of macro invocation\n   |              ^\n\n"}
[00:40:46] {"message":"no rules expected the token `?`","code":null,"level":"error","spans":[{"file_name":"/checkout/src/test/ui/macros/macro-at-most-once-rep-ted_replacement":null,"expansion":null}],"children":[],"rendered":"error: unexpected end of macro invocation\n  --> /checkout/src/test/ui/macros/macro-at-most-once-rep-ambig.rs:47:14\n   |\nLL |     barplus!(a); // ok\n   |              ^\n\n"}
[00:40:46] {"message":"aborting due to 11 previous errors","code":null,"level":"error","spans":[],"children":[],"rendered":"error: aborting due to 11 previous errors\n\n"}
---
[00:40:46] command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-tools-bin/compiletest" "--compile-lib-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib" "--run-lib-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/x86_64-unknown-linux-gnu/lib" "--rustc-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "--src-base" "/checkout/src/test/ui" "--build-base" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui" "--stage-id" "stage2-x86_64-unknown-linux-gnu" "--mode" "ui" "--target" "x86_64-unknown-linux-gnu" "--host" "x86_64-unknown-linux-gnu" "--llvm-filecheck" "/usr/lib/llvm-3.9/bin/FileCheck" "--host-rustcflags" "-Crpath -O -Zmiri -Zunstable-options " "--target-rustcflags" "-Crpath -O -Zmiri -Zunstable-options  -Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "--docck-python" "/usr/bin/python2.7" "--lldb-python" "/usr/bin/python2.7" "--gdb" "/usr/bin/gdb" "--quiet" "--llvm-version" "3.9.1\n" "--system-llvm" "--cc" "" "--cxx" "" "--cflags" "" "--llvm-components" "" "--llvm-cxxflags" "" "--adb-path" "adb" "--adb-test-dir" "/data/tmp/work" "--android-cross-path" "" "--color" "always"
[00:40:46] expected success, got: exit code: 101
[00:40:46]
[00:40:46]
[00:40:46] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test
[00:40:46] Build completed unsuccessfully in 0:02:18
[00:40:46] Makefile:58: recipe for target 'check' failed
[00:40:46] make: *** [check] Error 1
---
$ ls -lat $HOME/Library/Logs/DiagnosticReports/
ls: cannot access /home/travis/Library/Logs/DiagnosticReports/: No such file or directory
travis_time:end:084a03fa:start=1522980977446315829,finish=1522980977453955318,duration=7639489
travis_fold:end:after_failure.2
travis_fold:start:after_failure.3
travis_time:start:0f49c4f8
$ find $HOME/Library/Logs/DiagnosticReports -type f -name '*.crash' -not -name '*.stage2-*.crash' -not -name 'com.apple.CoreSimulator.CoreSimulatorService-*.crash' -exec printf travis_fold":start:crashlog\n\033[31;1m%s\033[0m\n" {} \; -exec head -750 {} \; -exec echo travis_fold":"end:crashlog \; || true
find: `/home/travis/Library/Logs/DiagnosticReports': No such file or directory
travis_time:end:0f49c4f8:start=1522980977460915259,finish=1522980977468588665,duration=7673406
travis_fold:end:after_failure.3
travis_fold:start:after_failure.4
travis_time:start:19721a36
$ dmesg | grep -i kill
[   10.700008] init: failsafe main process (1093) killed by TERM signal

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN.

clarfonthey · 2018-04-06T02:43:52Z

I was going to say that disallowing ? as a separator seems weird, but then I tried:

macro_rules! test {
    ($($t: ident)**) => {
        println!("{}", stringify!($($t)**));
    }
}

fn main() {
    let (a, b, c) = (1, 2, 3);
    println!("{}", test!(a * b * c));
}

Which yields a very weird error. Using ? doesn't seem to do so.

alexreg · 2018-04-06T03:07:48Z

@clarcharr Not weird at all, actually. :-) Since allowing * or + as separators would lead to ambiguous parsing, they're disallowed. $($t:ident)** is thus interpreted as $($t: ident)* (no separator) followed by the literal *, which means that's the appropriate error.

clarfonthey · 2018-04-06T18:24:17Z

@alexreg I agree, but the error in no way indicates that the separator is disallowed. It simply parses expecting a b c * instead of a * b * c.

In hindsight, this makes a lot of sense, but the errors could definitely be improved. I agree that disallowing ? makes the most sense here.

alexreg · 2018-04-06T20:13:18Z

@clarcharr Hmm. I see your point, but I still think the error message is essentially good as-is. Maybe what we need is a note attached to the existing error message when a match fails and it detects * or + following a Kleene op.

kennytm · 2018-04-07T06:27:41Z

@bors try

Please schedule a check-only crater run.

bors · 2018-04-07T06:27:51Z

⌛ Trying commit 54bba4c with merge f5d618a...

@durka

Update `?` repetition disambiguation. **Do not merge** (yet) This is a test implementation of some ideas from discussion in #48075 . This PR - disallows `?` repetition from taking a separator, since the separator is never used. - disallows the use of `?` as a separator. This allows patterns like `$(a)?+` to match `+` and `a+` rather than `a?a?a`. This is a _breaking change_, but maybe that's ok? Perhaps a crater run is the right approach? cc @durka @alexreg @nikomatsakis

bors · 2018-04-07T08:32:47Z

☀️ Test successful - status-travis
State: approved= try=True

mark-i-m · 2018-04-07T14:51:29Z

@kennytm

Please schedule a check-only crater run.

How do I do that?

kennytm · 2018-04-07T14:52:49Z

@mark-i-m That's only a message to the people who run the crater 😅

Mark-Simulacrum · 2018-04-13T03:25:11Z

A check-only crater run has been commenced; ETA is somewhat unknown but probably less than 5 days.

Mark-Simulacrum · 2018-04-14T22:21:21Z

Crater results are at: http://cargobomb-reports.s3.amazonaws.com/pr-49719/index.html. These results show 0 regressions; crater is green. Note that Crater does not test crates on Windows.

(interested observers: Crater is a tool for testing the impact of changes on the crates.io ecosystem. You can find out more at the repo if you're curious)

petrochenkov · 2018-04-15T22:01:29Z

@bors r+

bors · 2018-04-15T22:01:30Z

📌 Commit 54bba4c has been approved by petrochenkov

bors · 2018-04-16T00:06:17Z

⌛ Testing commit 54bba4c with merge d6ba1b9...

@durka

Update `?` repetition disambiguation. **Do not merge** (yet) This is a test implementation of some ideas from discussion in #48075 . This PR - disallows `?` repetition from taking a separator, since the separator is never used. - disallows the use of `?` as a separator. This allows patterns like `$(a)?+` to match `+` and `a+` rather than `a?a?a`. This is a _breaking change_, but maybe that's ok? Perhaps a crater run is the right approach? cc @durka @alexreg @nikomatsakis

pietroalbini · 2018-06-03T20:48:09Z

Personally I'd prefer if we implement this as a deprecation warning so we can change the behavior in a future edition instead of risking to break existing behavior. We shouldn't break things without warning if there is not a big reason to do that (such as fixing soundness holes).

oli-obk · 2018-06-03T20:51:35Z

Clippy broke. I think I fixed it with some feature gate.

mark-i-m · 2018-06-03T21:44:34Z

Oh, hmm... That's good to know... Maybe the edition would be the best way to turn this on...

alexreg · 2018-06-04T00:24:56Z

@mark-i-m How do editions work? Would this feature only be enabled for Rust 2018 code then?

mark-i-m · 2018-06-04T00:39:43Z

I think that would lead to the least confusion. We would warn now and then make it a hard error in the new edition. Then we could stabilize the feature some time in the 2018 edition...

Some other options are

accept the breaking change and stabilize this whenever we want.
rollback the breaking change. Keep the weird behavior we had before and switch to the new behavior (of this PR) after the edition. Stabilize when we want, even though the behavior will subtly change.

Both of these alternatives seem less good than just waiting a few months and deprecating the old behavior...

alexreg · 2018-06-04T01:02:23Z

I’m not against this. Sounds fair.

mark-i-m · 2018-06-04T02:27:58Z

I opened #51336 as a potential fix in the case we decide to roll this back for the 2015 edition without a feature gate.

nikomatsakis · 2018-06-07T14:41:05Z

Regardless of whether we should change the behavior here, I don't feel like this PR followed proper procedure. There should have been an official decision (with a FCP) before we merged this. I don't recall any such decision, am I forgetting something?

Thanks @mark-i-m for opening #51336

nikomatsakis · 2018-06-07T14:44:55Z

I think my preference would be that we do the following:

Revert this PR straight up.
Consider separately the question of whether to change the behavior in the new edition:
- if we are going to do so, we need to have a migration lint that detects the problem in the old edition. Ideally, we would migrate the macro as well, but I think right now we have no "simple way" to express the old semantics. This might be a problem we need to address.
- Point is, I do not think we are ready to do the full effects of [WIP] undo #49719 for rust 2015 with feature flag #51336 at this point.

@mark-i-m would you be up for preparing a "straight" revert PR to give us time to revisit this question?

nikomatsakis · 2018-06-07T14:51:59Z

(I filed #51416 to track a revert; we should still discuss the right thing to do afterwards. I personally like the idea of phasing this in with the new edition.)

This reverts commit d6ba1b9, reversing changes made to 8de5353.

@nikomatsakis

…tsakis Revert rust-lang#49719 This also needs to be backported into beta. Fixes rust-lang#51416. r? @nikomatsakis

Rollup of 9 pull requests Successful merges: - #51186 (Remove two redundant .nll.stderr files) - #51283 (Deny #[cfg] and #[cfg_attr] on generic parameters.) - #51368 (Fix the use of closures within #[panic_implementation]) - #51380 (Remove dependency on fmt_macros from typeck) - #51389 (rustdoc: Fix missing stability and src links for inlined external macros) - #51399 (NLL performance boost) - #51407 (Update RLS and Rustfmt) - #51417 (Revert #49719) - #51420 (Tries to address the recent network issues) Failed merges:

This reverts commit d6ba1b9, reversing changes made to 8de5353.

@ghost

[beta] Rollup backports Merged and accepted: * #51417: Revert #49719 * #51283: Deny #[cfg] and #[cfg_attr] on generic parameters * #51328: Do not promote union field accesses r? @ghost

petrochenkov · 2018-06-09T14:12:43Z

My rule of thumb is that if it's something useful long-term and has <5 crates.io regressions then we should do it.
I agree this was a process mistake and the PR needed an FCP (I was probably in hurry and somehow forgot about it).

alexreg · 2018-06-09T16:58:11Z

@petrochenkov No worries. I agree with your thinking. We need to re-implement this patch for the 2018 edition at least, I think.

mark-i-m · 2018-06-30T02:10:59Z

Request for comments/FCP on newest implementation: #51934

No separator for ?. No ? as a separator.

b2ed17b

rust-highfive assigned petrochenkov Apr 6, 2018

rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Apr 6, 2018

mark-i-m mentioned this pull request Apr 6, 2018

tracking issue for ? macro repetition #48075

Closed

6 tasks

fix test

54bba4c

kennytm added S-waiting-on-crater Status: Waiting on a crater run to be completed. relnotes Marks issues that should be documented in the release notes of the next release. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Apr 7, 2018

kennytm added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-crater Status: Waiting on a crater run to be completed. labels Apr 15, 2018

bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Apr 15, 2018

pietroalbini added the T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. label Jun 3, 2018

mark-i-m added a commit to mark-i-m/rust that referenced this pull request Jun 4, 2018

undo rust-lang#49719 for rust 2015 with feature flag

3277a06

mark-i-m mentioned this pull request Jun 4, 2018

[WIP] undo #49719 for rust 2015 with feature flag #51336

Closed

nikomatsakis mentioned this pull request Jun 7, 2018

semantics of $($x:tt)?* were changed in Rust 2015, should revert #51416

Closed

kennytm pushed a commit to kennytm/rust that referenced this pull request Jun 7, 2018

Revert "Auto merge of rust-lang#49719 - mark-i-m:no_sep, r=petrochenkov"

1df7817

This reverts commit d6ba1b9, reversing changes made to 8de5353.

kennytm added a commit to kennytm/rust that referenced this pull request Jun 7, 2018

Rollup merge of rust-lang#51417 - pietroalbini:revert-49719, r=nikoma…

e46ef1b

…tsakis Revert rust-lang#49719 This also needs to be backported into beta. Fixes rust-lang#51416. r? @nikomatsakis

kennytm mentioned this pull request Jun 7, 2018

Rollup of 9 pull requests #51426

Merged

pietroalbini mentioned this pull request Jun 8, 2018

[beta] Rollup backports #51432

Merged

bors pushed a commit that referenced this pull request Jun 9, 2018

Revert "Auto merge of #49719 - mark-i-m:no_sep, r=petrochenkov"

efce22c

This reverts commit d6ba1b9, reversing changes made to 8de5353.

petrochenkov mentioned this pull request Jun 9, 2018

Revert #49719 #51417

Merged

mark-i-m mentioned this pull request Jun 30, 2018

Change behavior of ? as a macro separator and Kleene op in 2018 edition #51934

Closed

mark-i-m deleted the no_sep branch November 14, 2018 16:40

pnkfelix mentioned this pull request Dec 3, 2018

NLL error on closure, but not on equivalent function #55526

Closed

Centril mentioned this pull request Dec 10, 2018

Extending ? macro repetition to Rust 2015 #56668

Closed

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Update `?` repetition disambiguation. #49719

Update `?` repetition disambiguation. #49719

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mark-i-m commented Jun 30, 2018

Update ? repetition disambiguation. #49719

Update ? repetition disambiguation. #49719

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mark-i-m commented Jun 30, 2018

Update `?` repetition disambiguation. #49719

Update `?` repetition disambiguation. #49719

mark-i-m commented Apr 6, 2018 •

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