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Re: What is "S" in CSS grammar?

From: Peng Yu <pengyu.ut@gmail.com>
Date: Tue, 27 Dec 2011 19:24:46 -0600
Message-ID: <CABrM6wmZkASQzCuv_H5HLfVJvJVFQ8VzEQR6EEkZ7nG7DCnFdg@mail.gmail.com>
To: "Tab Atkins Jr." <jackalmage@gmail.com>
Cc: www-style@w3.org
On Tue, Dec 27, 2011 at 5:39 PM, Tab Atkins Jr. <jackalmage@gmail.com> wrote:
> On Tue, Dec 27, 2011 at 2:24 PM, Peng Yu <pengyu.ut@gmail.com> wrote:
>> Hi,
>>
>> http://www.w3.org/TR/CSS2
>>
>> The above document mentioned something link this.
>>
>> hexcolor
>> : HASH S*
>> ;
>>
>> I also see the following. I'm wondering if the following S is the above S.
>>
>> S s|\\0{0,4}(53|73)(\r\n|[ \t\r\n\f])?|\\s
>>
>> I know some of above syntax, but not all. Could anybody help me
>> understand what the above sentence mean?
>>
>> I'm not familiar enough with flex syntax. Sorry for asking a naive question.
>
> The S* you see there comes from Chapter 4.1.1, where it's defined as
> "[ \t\r\n\f]+".
>
> The S definition you've quoted from Appendix G is used in the lexical
> scanner to represent a literal "S" or "s" character (or an escaped
> variant of those two).  I'm not sure if there's a conflict there, or
> if the tokens on the right side of the lexical scanner definitions are
> drawn from a different place from the ones on the left.

\t\r\n are quite standard. But I don't find the definition of '\f' in
gnu flex manual. Does anybody know what it is?

-- 
Regards,
Peng
Received on Wednesday, 28 December 2011 01:25:13 GMT

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