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[css3-syntax] Update the charset rules to latest proposal from Anne.
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‎css3-syntax/Overview.html‎

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<meta content="CSS Syntax Module Level 3 (CSS3 Syntax)" name=dcterms.title>
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<meta content=text name=dcterms.type>
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<meta content=2012-10-23 name=dcterms.issued>
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<meta content=2012-10-31 name=dcterms.issued>
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<meta content="http://dev.w3.org/csswg/css3-syntax/" name=dcterms.creator>
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<meta content=W3C name=dcterms.publisher>
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<meta content="http://www.w3.org/TR/2012/ED-css3-syntax-20121023/"
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<meta content="http://www.w3.org/TR/2012/ED-css3-syntax-20121031/"
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name=dcterms.identifier>
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<link href="#contents" rel=contents>
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<link href="#index" rel=index>
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<h1>CSS Syntax Module Level 3</h1>
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<h2 class="no-num no-toc" id=longstatus-date>Editor's Draft 23 October
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<h2 class="no-num no-toc" id=longstatus-date>Editor's Draft 31 October
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2012</h2>
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<dl>
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<p> To decode the stream of bytes into a stream of characters, UAs must
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follow these steps.
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<p> The algorithms to <a
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href="http://encoding.spec.whatwg.org/#concept-encoding-get"><dfn
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id=get-an-encoding>get an encoding</dfn></a> and <a
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href="http://encoding.spec.whatwg.org/#decode"><dfn
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id=decode>decode</dfn></a> are defined in the <a
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href="http://encoding.spec.whatwg.org/">Encoding Standard</a>.
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<ol>
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<li> Let <var>label</var> be null.
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<li> Let <var>encoding</var> be utf-8.
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<li> If HTTP or equivalent protocol defines an encoding (e.g. via the
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charset parameter of the Content-Type header), set <var>label</var> to
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the value so defined.
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charset parameter of the Content-Type header), <a
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href="#get-an-encoding"><i>get an encoding</i></a> for the specified
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value. If that does not return failure, set <var>encoding</var> to the
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return value and jump to the last step of this algorithm.
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<li> If <var>label</var> is null, check the byte stream. If the first
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several bytes match the hex sequence
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<li> Check the byte stream. If the first several bytes match the hex
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sequence
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<pre>40 63 68 61 72 73 65 74 20 22 (XX)* 22 3B</pre>
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then set <var>label</var> to the sequence of XX bytes, decoded per
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<code>windows-1252</code>.
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then <a href="#get-an-encoding"><i>get an encoding</i></a> for the
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sequence of XX bytes, decoded per <code>windows-1252</code>, and let
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<var>temp</var> be the return value.
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<p class=note> Note: Anything ASCII-compatible will do, so using
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<code>windows-1252</code> is fine.
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<li> If <var>label</var> is null, set <var>label</var> to the value of
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charset attribute on the <code>&lt;link></code> element that caused the
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style sheet to be included, if any.
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<p> If <var>temp</var> is <code>utf-16</code> or <code>utf-16be</code>,
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set <var>temp</var> to <code>utf-8</code>. If <var>temp</var> is not
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failure, set <var>encoding</var> to it and jump to the last step.
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<p class=note> This mimics HTML <code>&lt;meta></code> behavior.
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<li> If <var>label</var> is null, there is a referring style sheet or
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document, and that referring sheet or document's encoding is not
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<code>utf-16</code> or <code>utf-16be</code>, set <var>label</var> to
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that encoding.
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<li> <a href="#get-an-encoding"><i>Get an encoding</i></a> for the value
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of the <code>charset</code> attribute on the <code>&lt;link></code>
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element or <code>&lt;?xml-stylesheet?></code> processing instruction that
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caused the style sheet to be included, if any. If that does not return
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failure, set <var>encoding</var> to the return value and jump to the last
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step.
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<li> Let <var>encoding</var> be the result of <a
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href="http://encoding.spec.whatwg.org/#concept-encoding-get">getting an
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encoding from <var>label</var></a>. If <var>encoding</var> is
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<code>failure</code>, set it to <code>utf-8</code>.
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<li> Set <var>encoding</var> to the encoding of the referring style sheet
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or document, if any.
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<li> <a href="http://encoding.spec.whatwg.org/#decode">Decode the byte
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stream</a> using fallback encoding <var>encoding</var>.
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<li> <a href="#decode"><i>Decode</i></a> the byte stream using fallback
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encoding <var>encoding</var>.
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<p class=note> Note: the <a href="#decode"><i>decode</i></a> algorithm
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lets the byte order mark (BOM) take precedence, hence the usage of the
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term "fallback" above.
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</ol>
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<p class=issue> Anne says that steps 4/5 should be an input to this
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algorithm from the specs that define importing stylesheet, to make the
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algorithm as a whole cleaner. Perhaps abstract it into the concept of an
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"environment charset" or something?
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<h4 id=preprocessing-the-input-stream><span class=secno>3.2.1. </span>
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Preprocessing the input stream</h4>
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<li>Declaration-value mode, <a href="#declaration-value-mode0"
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title="Declaration-value mode"><strong>3.6.8.</strong></a>
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<li>decode, <a href="#decode" title=decode><strong>3.2.</strong></a>
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<li>digit, <a href="#digit" title=digit><strong>3.4.3.</strong></a>
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<li>Dimension state, <a href="#dimension-state0"
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<li>Finish parsing, <a href="#finish-parsing0"
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title="Finish parsing"><strong>3.6.22.</strong></a>
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<li>get an encoding, <a href="#get-an-encoding"
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title="get an encoding"><strong>3.2.</strong></a>
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<li>hashless color quirk list, <a href="#hashless-color-quirk-list"
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title="hashless color quirk list"><strong>3.6.15.</strong></a>
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‎css3-syntax/Overview.src.html‎

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@@ -253,42 +253,67 @@ <h3>
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To decode the stream of bytes into a stream of characters,
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UAs must follow these steps.
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<p>
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The algorithms to <a href="http://encoding.spec.whatwg.org/#concept-encoding-get"><dfn>get an encoding</dfn></a>
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and <a href="http://encoding.spec.whatwg.org/#decode"><dfn>decode</dfn></a>
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are defined in the <a href="http://encoding.spec.whatwg.org/">Encoding Standard</a>.
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<ol>
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<li>
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Let <var>label</var> be null.
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Let <var>encoding</var> be utf-8.
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<li>
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If HTTP or equivalent protocol defines an encoding (e.g. via the charset parameter of the Content-Type header),
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set <var>label</var> to the value so defined.
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<i>get an encoding</i> for the specified value.
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If that does not return failure,
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set <var>encoding</var> to the return value
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and jump to the last step of this algorithm.
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<li>
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If <var>label</var> is null, check the byte stream. If the first several bytes match the hex sequence
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Check the byte stream. If the first several bytes match the hex sequence
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<pre>40 63 68 61 72 73 65 74 20 22 (XX)* 22 3B</pre>
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then set <var>label</var> to the sequence of XX bytes, decoded per <code>windows-1252</code>.
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then <i>get an encoding</i> for the sequence of XX bytes,
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decoded per <code>windows-1252</code>,
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and let <var>temp</var> be the return value.
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<p class='note'>
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Note: Anything ASCII-compatible will do, so using <code>windows-1252</code> is fine.
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<li>
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If <var>label</var> is null,
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set <var>label</var> to the value of charset attribute on the <code>&lt;link></code> element that caused the style sheet to be included, if any.
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<p>
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If <var>temp</var> is <code>utf-16</code> or <code>utf-16be</code>,
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set <var>temp</var> to <code>utf-8</code>.
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If <var>temp</var> is not failure,
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set <var>encoding</var> to it
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and jump to the last step.
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<p class='note'>
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This mimics HTML <code>&lt;meta></code> behavior.
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<li>
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If <var>label</var> is null,
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there is a referring style sheet or document,
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and that referring sheet or document's encoding is not <code>utf-16</code> or <code>utf-16be</code>,
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set <var>label</var> to that encoding.
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<i>Get an encoding</i> for the value of the <code>charset</code> attribute on the <code>&lt;link></code> element or <code>&lt;?xml-stylesheet?></code> processing instruction that caused the style sheet to be included, if any.
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If that does not return failure,
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set <var>encoding</var> to the return value
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and jump to the last step.
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<li>
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Let <var>encoding</var> be the result of <a href="http://encoding.spec.whatwg.org/#concept-encoding-get">getting an encoding from <var>label</var></a>.
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If <var>encoding</var> is <code>failure</code>, set it to <code>utf-8</code>.
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Set <var>encoding</var> to the encoding of the referring style sheet or document,
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if any.
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<li>
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<a href="http://encoding.spec.whatwg.org/#decode">Decode the byte stream</a> using fallback encoding <var>encoding</var>.
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<i>Decode</i> the byte stream using fallback encoding <var>encoding</var>.
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<p class='note'>
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Note: the <i>decode</i> algorithm lets the byte order mark (BOM) take precedence,
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hence the usage of the term "fallback" above.
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</ol>
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<p class='issue'>
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Anne says that steps 4/5 should be an input to this algorithm from the specs that define importing stylesheet,
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to make the algorithm as a whole cleaner.
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Perhaps abstract it into the concept of an "environment charset" or something?
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<h4>
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Preprocessing the input stream</h4>

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