changeset
[css-syntax] Clarify how to decode from bytes
Fri, 03 Jan 2014 12:41:33 +0000
- author
- Simon Sapin <simon.sapin@exyr.org>
- date
- Fri, 03 Jan 2014 12:41:33 +0000
- changeset 9701
- a067b6c20248
- parent 9700
- 6c5d1704f506
- child 9702
- 04834ea861b7
[css-syntax] Clarify how to decode from bytes
| css-syntax/Overview.html | file | annotate | diff | comparison | revisions | |
| css-syntax/Overview.src.html | file | annotate | diff | comparison | revisions |
1.1 --- a/css-syntax/Overview.html Fri Jan 03 11:59:47 2014 +0000 1.2 +++ b/css-syntax/Overview.html Fri Jan 03 12:41:33 2014 +0000 1.3 @@ -429,18 +429,21 @@ 1.4 which the user agent must use to decode the bytes into <a data-link-type=dfn href=#code-point title="code points">code points</a>. 1.5 1.6 <p> To decode the stream of bytes into a stream of <a data-link-type=dfn href=#code-point title="code points">code points</a>, 1.7 - UAs must follow these steps. 1.8 - 1.9 -<p> The algorithms to <dfn data-dfn-type=dfn data-noexport="" id=get-an-encoding><a href=http://encoding.spec.whatwg.org/#concept-encoding-get>get an encoding</a><a class=self-link href=#get-an-encoding></a></dfn> 1.10 - and <dfn data-dfn-type=dfn data-noexport="" id=decode><a href=http://encoding.spec.whatwg.org/#decode>decode</a><a class=self-link href=#decode></a></dfn> 1.11 - are defined in <a data-biblio-type=normative data-link-type=biblio href=#encoding title=encoding>[ENCODING]</a>. 1.12 - 1.13 -<p> First, <dfn data-dfn-type=dfn data-noexport="" id=determine-the-fallback-encoding>determine the fallback encoding<a class=self-link href=#determine-the-fallback-encoding></a></dfn>: 1.14 + UAs must use the <a href=http://encoding.spec.whatwg.org/#decode>decode</a> algorithm 1.15 + defined in <a data-biblio-type=normative data-link-type=biblio href=#encoding title=encoding>[ENCODING]</a>, 1.16 + with the fallback encoding determined as follows. 1.17 + 1.18 +<p class=note> Note: The <a href=http://encoding.spec.whatwg.org/#decode>decode</a> algorithm 1.19 + gives precedence to a byte order mark (BOM), 1.20 + and only uses the fallback when none is found. 1.21 + 1.22 +<p> To <dfn data-dfn-type=dfn data-noexport="" id=determine-the-fallback-encoding>determine the fallback encoding<a class=self-link href=#determine-the-fallback-encoding></a></dfn>: 1.23 1.24 <ol> 1.25 <li> 1.26 If HTTP or equivalent protocol defines an encoding (e.g. via the charset parameter of the Content-Type header), 1.27 - <a data-link-type=dfn href=#get-an-encoding title="get an encoding">get an encoding</a> for the specified value. 1.28 + <a href=http://encoding.spec.whatwg.org/#concept-encoding-get>get an encoding</a> <a data-biblio-type=normative data-link-type=biblio href=#encoding title=encoding>[ENCODING]</a> 1.29 + for the specified value. 1.30 If that does not return failure, 1.31 use the return value as the fallback encoding. 1.32 1.33 @@ -448,16 +451,18 @@ 1.34 Otherwise, check the byte stream. If the first several bytes match the hex sequence 1.35 1.36 <pre>40 63 68 61 72 73 65 74 20 22 (not 22)* 22 3B</pre> 1.37 -<p> then <a data-link-type=dfn href=#get-an-encoding title="get an encoding">get an encoding</a> for the sequence of <code>(not 22)*</code> bytes, 1.38 +<p> then <a href=http://encoding.spec.whatwg.org/#concept-encoding-get>get an encoding</a> <a data-biblio-type=normative data-link-type=biblio href=#encoding title=encoding>[ENCODING]</a> 1.39 + for the sequence of <code>(not 22)*</code> bytes, 1.40 decoded per <code>windows-1252</code>. 1.41 1.42 -<p class=note> Note: Anything ASCII-compatible will do, so using <code>windows-1252</code> is fine. 1.43 +<p class=note> Note: Anything ASCII-compatible will do since valid labels are all ASCII, 1.44 + so using <code>windows-1252</code> is fine. 1.45 1.46 1.47 <p class=note> Note: The byte sequence above, 1.48 when decoded as ASCII, 1.49 is the string "<code>@charset "…";</code>", 1.50 - where the "…" is the sequence of bytes corresponding to the encoding’s name. 1.51 + where the "…" is the sequence of bytes corresponding to the encoding’s label. 1.52 1.53 <p> If the return value was <code>utf-16</code> or <code>utf-16be</code>, 1.54 use <code>utf-8</code> as the fallback encoding; 1.55 @@ -474,10 +479,6 @@ 1.56 Otherwise, use <code>utf-8</code> as the fallback encoding. 1.57 </ol> 1.58 1.59 -<p> Then, <a data-link-type=dfn href=#decode title=decode>decode</a> the byte stream using the fallback encoding. 1.60 - 1.61 -<p class=note> Note: the <a data-link-type=dfn href=#decode title=decode>decode</a> algorithm lets the byte order mark (BOM) take precedence, 1.62 - hence the usage of the term "fallback" above. 1.63 1.64 <h3 class="heading settled heading" data-level=3.3 id=environment-encoding><span class=secno>3.3 </span><span class=content> 1.65 Environment encoding</span><a class=self-link href=#environment-encoding></a></h3> 1.66 @@ -502,7 +503,8 @@ 1.67 1.68 <p> <ul> 1.69 <li> 1.70 - <a data-link-type=dfn href=#get-an-encoding title="get an encoding">Get an encoding</a> for the value of the <code>charset</code> attribute of the element, if any. 1.71 + <a href=http://encoding.spec.whatwg.org/#concept-encoding-get>Get an encoding</a> <a data-biblio-type=normative data-link-type=biblio href=#encoding title=encoding>[ENCODING]</a> 1.72 + for the value of the <code>charset</code> attribute of the element, if any. 1.73 If that does not return failure, 1.74 use the return value as the environment encoding. 1.75 1.76 @@ -525,7 +527,8 @@ 1.77 1.78 <p> <ul> 1.79 <li> 1.80 - <a data-link-type=dfn href=#get-an-encoding title="get an encoding">Get an encoding</a> for the value of the <code>charset</code> <a href=http://www.w3.org/TR/xml-stylesheet/#dt-pseudo-attribute>pseudo-attribute</a> of the processing instruction, if any. 1.81 + <a href=http://encoding.spec.whatwg.org/#concept-encoding-get>Get an encoding</a> <a data-biblio-type=normative data-link-type=biblio href=#encoding title=encoding>[ENCODING]</a> 1.82 + for the value of the <code>charset</code> <a href=http://www.w3.org/TR/xml-stylesheet/#dt-pseudo-attribute>pseudo-attribute</a> of the processing instruction, if any. 1.83 If that does not return failure, 1.84 use the return value as the environment encoding. 1.85 1.86 @@ -5038,7 +5041,6 @@ 1.87 <li><dashndashdigit-ident>, <a href=#typedef-dashndashdigit-ident title="section 6.2">6.2</a> 1.88 <li>declaration, <a href=#declaration title="section 5">5</a> 1.89 <li><declaration-list>, <a href=#typedef-declaration-list title="section 7.1">7.1</a> 1.90 -<li>decode, <a href=#decode title="section 3.2">3.2</a> 1.91 <li><delim-token>, <a href=#typedef-delim-token title="section 4">4</a> 1.92 <li>determine the fallback encoding, <a href=#determine-the-fallback-encoding title="section 3.2">3.2</a> 1.93 <li>digit, <a href=#digit title="section 4.2">4.2</a> 1.94 @@ -5052,7 +5054,6 @@ 1.95 <li>escaping, <a href=#escaping0 title="section 2.1">2.1</a> 1.96 <li>function, <a href=#function title="section 5">5</a> 1.97 <li><function-token>, <a href=#typedef-function-token title="section 4">4</a> 1.98 -<li>get an encoding, <a href=#get-an-encoding title="section 3.2">3.2</a> 1.99 <li><hash-token>, <a href=#typedef-hash-token title="section 4">4</a> 1.100 <li>hex digit, <a href=#hex-digit title="section 4.2">4.2</a> 1.101 <li>identifier, <a href=#identifier title="section 4.2">4.2</a>
2.1 --- a/css-syntax/Overview.src.html Fri Jan 03 11:59:47 2014 +0000 2.2 +++ b/css-syntax/Overview.src.html Fri Jan 03 12:41:33 2014 +0000 2.3 @@ -265,18 +265,21 @@ 2.4 which the user agent must use to decode the bytes into <a>code points</a>. 2.5 2.6 To decode the stream of bytes into a stream of <a>code points</a>, 2.7 - UAs must follow these steps. 2.8 - 2.9 - The algorithms to <dfn><a href="http://encoding.spec.whatwg.org/#concept-encoding-get">get an encoding</a></dfn> 2.10 - and <dfn><a href="http://encoding.spec.whatwg.org/#decode">decode</a></dfn> 2.11 - are defined in [[!ENCODING]]. 2.12 - 2.13 - First, <dfn>determine the fallback encoding</dfn>: 2.14 + UAs must use the <a href="http://encoding.spec.whatwg.org/#decode">decode</a> algorithm 2.15 + defined in [[!ENCODING]], 2.16 + with the fallback encoding determined as follows. 2.17 + 2.18 + Note: The <a href="http://encoding.spec.whatwg.org/#decode">decode</a> algorithm 2.19 + gives precedence to a byte order mark (BOM), 2.20 + and only uses the fallback when none is found. 2.21 + 2.22 + To <dfn>determine the fallback encoding</dfn>: 2.23 2.24 <ol> 2.25 <li> 2.26 If HTTP or equivalent protocol defines an encoding (e.g. via the charset parameter of the Content-Type header), 2.27 - <a>get an encoding</a> for the specified value. 2.28 + <a href="http://encoding.spec.whatwg.org/#concept-encoding-get">get an encoding</a> [[!ENCODING]] 2.29 + for the specified value. 2.30 If that does not return failure, 2.31 use the return value as the fallback encoding. 2.32 2.33 @@ -285,16 +288,18 @@ 2.34 2.35 <pre>40 63 68 61 72 73 65 74 20 22 (not 22)* 22 3B</pre> 2.36 2.37 - then <a>get an encoding</a> for the sequence of <code>(not 22)*</code> bytes, 2.38 + then <a href="http://encoding.spec.whatwg.org/#concept-encoding-get">get an encoding</a> [[!ENCODING]] 2.39 + for the sequence of <code>(not 22)*</code> bytes, 2.40 decoded per <code>windows-1252</code>. 2.41 2.42 - Note: Anything ASCII-compatible will do, so using <code>windows-1252</code> is fine. 2.43 + Note: Anything ASCII-compatible will do since valid labels are all ASCII, 2.44 + so using <code>windows-1252</code> is fine. 2.45 2.46 2.47 Note: The byte sequence above, 2.48 when decoded as ASCII, 2.49 is the string "<code>@charset "…";</code>", 2.50 - where the "…" is the sequence of bytes corresponding to the encoding's name. 2.51 + where the "…" is the sequence of bytes corresponding to the encoding's label. 2.52 2.53 If the return value was <code>utf-16</code> or <code>utf-16be</code>, 2.54 use <code>utf-8</code> as the fallback encoding; 2.55 @@ -311,10 +316,6 @@ 2.56 Otherwise, use <code>utf-8</code> as the fallback encoding. 2.57 </ol> 2.58 2.59 - Then, <a>decode</a> the byte stream using the fallback encoding. 2.60 - 2.61 - Note: the <a>decode</a> algorithm lets the byte order mark (BOM) take precedence, 2.62 - hence the usage of the term "fallback" above. 2.63 2.64 <h3 id="environment-encoding"> 2.65 Environment encoding</h3> 2.66 @@ -339,7 +340,8 @@ 2.67 2.68 <ul> 2.69 <li> 2.70 - <a>Get an encoding</a> for the value of the <code>charset</code> attribute of the element, if any. 2.71 + <a href="http://encoding.spec.whatwg.org/#concept-encoding-get">Get an encoding</a> [[!ENCODING]] 2.72 + for the value of the <code>charset</code> attribute of the element, if any. 2.73 If that does not return failure, 2.74 use the return value as the environment encoding. 2.75 2.76 @@ -365,7 +367,8 @@ 2.77 2.78 <ul> 2.79 <li> 2.80 - <a>Get an encoding</a> for the value of the <code>charset</code> <a href=http://www.w3.org/TR/xml-stylesheet/#dt-pseudo-attribute>pseudo-attribute</a> of the processing instruction, if any. 2.81 + <a href="http://encoding.spec.whatwg.org/#concept-encoding-get">Get an encoding</a> [[!ENCODING]] 2.82 + for the value of the <code>charset</code> <a href=http://www.w3.org/TR/xml-stylesheet/#dt-pseudo-attribute>pseudo-attribute</a> of the processing instruction, if any. 2.83 If that does not return failure, 2.84 use the return value as the environment encoding. 2.85
