[webkit-dev] The SrcN responsive images proposal

[Tab Atkins Jr.]

On Thu, Nov 7, 2013 at 3:39 PM, Timothy Hatcher <timothy at apple.com> wrote:
> On Nov 7, 2013, at 2:22 PM, Tab Atkins Jr. <jackalmage at gmail.com> wrote:
>> srcset's parsing algorithm *cannot* be extended in the future.  I gave
>> an example of how it would fail over on blink-dev; I can reproduce it
>> here if necessary.
>
> I don't subscribe to blink-dev. The WebKit community are the ones you need to convince.

A simple "Yes" would have sufficed.  I was just asking if I needed to
demonstrate it.  Take this markup:

<img srcset="foo 1x, bar 2x || baz 1x, qux 2x">

You expect this to break into two lists, "foo 1x, bar 2x" and "baz 1x,
qux 2x", which are then each split as currently proposed.

However, by the current parsing algorithm, || is read as an
unsupported descriptor, so it just breaks them into "foo 1x", "bar 2x
|| baz 1x", and "qux 2x".  The middle one is thrown away, because of
the duplicate x descriptor, and so the whole thing is just parsed to
the same value as "foo 1x, qux 2x", which is completely wrong.

>>> Designing this proposal around code formatting is a non-issue in my opinion
>>> and it surely didn't stop SVG from providing just one "d" attribute for
>>> <path>. Following the your logic, it should be d-N. Sure, <path d="…"> is
>>> primarily meant to be written by software.
>>
>> Please don't try to use reducto ad absurdum; it usually gives absurd
>> results.  The reasoning for multiple attributes is not "because it's a
>> list", it's because it's a list of lists, and would require three
>> different delimiters.
>
> Three whole delimiters. What a crime against humanity!

I'm not sure why you're being sarcastic and hostile.  Three delimiters
is a rather large mental tax for developers.  Being dismissive of
mental complexity isn't very friendly to authors.  It's not the
be-all-end-all, but it is important.

~TJ