Display \t in diagnostics code as four spaces
#45953
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@estebank nice PR! It definitely improves the behaviour of rustc regarding tabs :). However, tab == 4 spaces replacements (what this PR is doing) are not a emulation of what clang is doing. Instead, clang emulates a tabstop algorithm, meaning that a tab character jumps to the next tabstop. Tabstops are being placed at all 4 spaces. The basic algorithm is: add 1 space, then add another The difference is not observable if you only use tabs at the start of a line and once you have a non tab character you never use them again (which is how I structure all of my own code). You can only see the difference when there is a mix of tabs and spaces. With the tabs == 4 spaces algorithm, With the tabstops algorithm that clang is using, the sequences would become: As I've said above, it wouldn't make any difference for my own code, but it would maybe make a difference for other users. |
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@est31 I understand. I've changed the description from fixing the bug to merely CCing it. Supporting the proper tab stop algorithm will require some extra code in order for underlines to be correct as well. I feel that for now this is a good stop gap improvement on your code, even if not entirely correct as you point out. |
Definitely! Really like this PR :) |
kennytm
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Ping from triage, @pnkfelix — will you have time to look at this soon? |
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☔ The latest upstream changes (presumably #46116) made this pull request unmergeable. Please resolve the merge conflicts. |
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Triage ping — @pnkfelix could you take a look at this PR? Thanks! cc @rust-lang/compiler |
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r? @arielb1 |
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Triage ping — @arielb1 could you take a look at this PR? Thanks! |
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I don't know this code. r? @nikomatsakis |
| tab_pos.push(pos); | ||
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| // start with the tabs at the end of the line to replace them with 4 space chars |
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Am I missing something...? Why is it useful/important to go in reverse? (Doesn't seem harmful, but also not imp't.)
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oh, I see, duh. Otherwise the indices are invalid.
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@bors r+ |
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📌 Commit 9d80e22 has been approved by |
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Display `\t` in diagnostics code as four spaces Follow up to #44386 using the unicode variable width machinery from #45711 to replace tabs in the source code when displaying a diagnostic error with four spaces (instead of only one), while properly accounting for this when calculating underlines. Partly addresses #44618.
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☀️ Test successful - status-appveyor, status-travis |
Follow up to #44386 using the unicode variable width machinery from #45711 to replace tabs in the source code when displaying a diagnostic error with four spaces (instead of only one), while properly accounting for this when calculating underlines.
Partly addresses #44618.