W3C home > Mailing lists > Public > www-style@w3.org > February 2016

Re: [css-values] range-checking, calc(-5), and serialization

From: Tab Atkins Jr. <jackalmage@gmail.com>
Date: Tue, 16 Feb 2016 15:53:08 -0800
Message-ID: <CAAWBYDB7-7J+KqWjpKxshnjThj1FYqXKAzTTJd=1y8jwL+t0Lw@mail.gmail.com>
To: fantasai <fantasai.lists@inkedblade.net>
Cc: "www-style@w3.org" <www-style@w3.org>
On Tue, Feb 16, 2016 at 3:43 PM, fantasai <fantasai.lists@inkedblade.net> wrote:
> The definition for calc() states:
>
> https://www.w3.org/TR/2015/CR-css-values-3-20150611/
>  # The value resulting from an expression must be clamped to the
>  # range allowed in the target context.
>
> There's a few issues with this...
>
> Issue 1:
>   It doesn't state when this is clamped. Presumably the used value is
> clamped.
>   Assuming everyone agrees, I'll update the spec to say so.
>
> Issue 2:
>   This presumably means that ''width: calc(-5px)'' is valid, and treated as
> zero.
>   However, the serialization rules recently added to the spec state that
>     https://drafts.csswg.org/css-values-3/#calc-serialize
>     # If the result is a single value, serialize as that value,
>     # discarding the calc() wrapper.
>   This means that some calc() values will not be round-trippable.

Issue 2 is only an issue because of your suggested resolution for
Issue 1.  If the clamping happens "as soon as possible", then the
serialization rules would produce a "0" in that case.

~TJ
Received on Tuesday, 16 February 2016 23:53:55 UTC

This archive was generated by hypermail 2.4.0 : Friday, 25 March 2022 10:09:00 UTC