[csswg-drafts] [css-variables][css-syntax] Whitespace trimming and var() fallbacks (#6871)

andruud has just created a new issue for https://github.com/w3c/csswg-drafts:

== [css-variables][css-syntax] Whitespace trimming and var() fallbacks ==
I'd like to clarify one detail regarding whitespace trimming defined by [consume a declaration](https://drafts.csswg.org/css-syntax/#consume-declaration):

What is the computed value of `--x` here? `--x: a var(--invalid, b );`

I would interpret the current specs like this: the whitespace before `a` gets trimmed, but we don't remove any whitespace _inside_ the value, so `a var(--invalid, b )` (with no space in front) becomes the "parsed" value. Then, substitution-time, the `var()` reference resolves to its fallback `_b_` (using _ for space), and the post-substitution value becomes `a__b_`. At this point it may make sense to behave as if relevant parts of "consume a declaration" had been invoked on the final post-substitution token sequence, trimming the result to `a__b`, although it's not really clear if this is expected.

OR, do we trim the spaces around the `<declaration-value>` of the fallback at some point instead (for example, "anything we substitute in gets trimmed first")? In that case, the computed value would be `a_b`.

@tabatkins @emilio 

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/6871 using your GitHub account


-- 
Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config

Received on Thursday, 9 December 2021 14:08:25 UTC