[css-syntax] Simplify ident-like URL consumption

[jonathantneal]

The specification reads:

While the next two input code points are whitespace, consume the next input code point.

If I understand correctly, this will repeatedly consume whitespace until 0 or 1 whitespace input code points remain.

Then it reads:

If the next one or two input code points U+0022 QUOTATION MARK ("), U+0027 APOSTROPHE ('), or whitespace followed by U+0022 QUOTATION MARK (") or U+0027 APOSTROPHE ('), then create a <function-token>...

Could this be simplified?

While the next input code point is whitespace, consume it. If the next input code point is a U+0022 QUOTATION MARK (") or U+0027 APOSTROPHE ('), then create a <function-token>...

[tabatkins]

...huh, I have no idea why I wrote it that way.

[tabatkins]

Ah, looking at the history, I changed from your suggested text to the current text in https://github.com/csstools/csswg-drafts/commit/5f673863c0b1195fc4b8933b2e4d3893b1f8eae0, and now that I see it, I understand why - if there is any whitespace between the open-paren and the string, I need to preserve it, so the next token produced is a whitespace token.

(I can't just emit the function-token immediately and let normal whitespace processing handle that; I need to scan forward and see if it's going to be a normal function (containing a string) or if it needs to be specially parsed as a url-token (unquoted).)