Re: Lua CSS parser?

[Pierre-Yves Gérardy <pygy79@...>]

Writing a parser would be tedious, but not hard IMO.

The grammar definition include bad comments, bad strings, etc.

http://www.w3.org/TR/CSS2/grammar.html

The challenge to interpret the cascade and match the selectors to elements.
—Pierre-Yves


On Tue, May 27, 2014 at 9:02 PM, Andrew Starks <andrew.starks@trms.com> wrote:
>
>
>
> On Tue, May 27, 2014 at 1:33 PM, Tom N Harris <telliamed@whoopdedo.org>
> wrote:
>>
>> On Tuesday, May 27, 2014 12:20:49 PM Sean Conner wrote:
>> > is legal (and before you say no sane person would actually write the
>> > above,
>> > there's some saying I can't quite find that states that if it's
>> > possible, it
>> > will exist in some codebase somewhere).
>>
>> Worse than that, CSS requires that a parser must accept *illegal* syntax
>> without failing. It must pass over the nonsense, while balancing braces,
>> parenthesis, and quotes, then ignore what it doesn't understand.
>>
>>     @media screen {
>>      p { font-family: monospace }
>>      @foo @bar;
>>      p { color: red;  color{;color:maroon}; color: green }
>>      ) ( {} ) p {color: red }
>>      p {
>>        font-family: 'Times New Roman
>>        font-style: italic;
>>
>> A conforming CSS processor must be accept this and reduce it to
>>
>>     @media screen {
>>       p { font-family:monospace; color:green; font-style:italic; }
>>     }
>>
>> Now, if you don't mind being non-conforming, I don't think anyone will be
>> too
>> upset if you refuse to accept that unholy mess.
>>
>> --
>> tom <telliamed@whoopdedo.org>
>>
>
> If the OP has a specialized sand-box that is more restrictive than the rest
> of the world, then fine.
>
> However, skipping bad input is used almost all of the time. This is
> especially true for dealing with browser incompatibilities (IE5.5), etc.
>
> And then you have selectors that modify "all paragraphs not inside of class
> Foo", etc.
>
> A generic CSS parser / resource selector would be an extremely powerful
> tool, but it might be about as large as your average utf8 library. :)
>
> -Andrew