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[css-conditional-3] Remove "unknown" value concept #6312

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Merged
merged 1 commit into from
May 27, 2021
Merged

[css-conditional-3] Remove "unknown" value concept #6312

merged 1 commit into from
May 27, 2021

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andruud
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@andruud andruud commented May 26, 2021

The production now just produces "false".

See Issue #6175.

[css-conditional-3] Remove "unknown" value concept
055f862 
The  production now just produces "false".

See Issue 6175.
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andruud commented May 26, 2021

Plan (from the Blink perspective):

  • Optimistically spec that results in "false".
  • Add use-counters to Blink to understand the compat situation. (Wait ~6 months for data to come in).
  • Verify that Webkit is willing to make this change.
  • If compat situation allows it, make the change in Blink. Otherwise, CSSWG probably needs to revisit the issue, and we'll edit the spec again with some (less desirable) compromise.

Given that interop is pretty poor currently, I'm optimistic that it will be possible to make this change.

@dbaron, @mirisuzanne

tabatkins
tabatkins approved these changes May 26, 2021
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Looks great, and the plan seems spot-on as well. I won't merge since I'm not an editor, but r+

dbaron
dbaron approved these changes May 27, 2021
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This looks good to me as well.

I'd note this concept was originally introduced in 206498e, although the commit message doesn't mention it at all.

@dbaron dbaron merged commit d3c2b5c into w3c:main May 27, 2021
@andruud andruud deleted the purge_unknown branch May 27, 2021 18:21
blueboxd pushed a commit to blueboxd/chromium-legacy that referenced this pull request Jun 3, 2021
@andruud
Remove CSSSupportsParser::Result::kUnknown
aa1b5e5 
The spec has been updated to remove the "unknown" value concept [1].
The  production now just results in "false".

Since support for kUnknown was a work-in-progress that never reached
the web surface, we can just remove it.

Bug: 1052274

[1] w3c/csswg-drafts#6312

Change-Id: Iec0b54e7d156518a1e5b38d8e88d7d9c8bdb3d9e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2932039
Reviewed-by: Kevin Babbitt 
Commit-Queue: Anders Hartvoll Ruud 
Cr-Commit-Position: refs/heads/master@{#888553}
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andruud commented Jun 8, 2021

Investigating a bit more, looks like Chromium already behaves according to the new spec text. The reason Chromium appears to evaluate not fn() to false in the demo is because not fn() is actually invalid grammar. (, requires one or more tokens).

@fantasai fantasai mentioned this pull request Nov 8, 2021
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