[css-values] Add some reasonable things to the grammar definitions.

Author: tabatkins

css-values/Overview.html

@@ -11,12 +11,12 @@
    rel=dcterms.rights>
   <meta content="CSS Values and Units Module Level 3" name=dcterms.title>
   <meta content=text name=dcterms.type>
-  <meta content=2013-08-30 name=dcterms.date>
+  <meta content=2013-10-08 name=dcterms.date>
   <meta content="Håkon Wium Lie" name=dcterms.creator>
   <meta content="Tab Atkins" name=dcterms.creator>
   <meta content="Elika J. Etemad" name=dcterms.creator>
   <meta content=W3C name=dcterms.publisher>
-  <meta content="http://www.w3.org/TR/2013/CR-css3-values-20130830/"
+  <meta content="http://www.w3.org/TR/2013/CR-css3-values-20131008/"
    name=dcterms.identifier>
   <style type="text/css">
     code, small { white-space: nowrap }
@@ -41,15 +41,15 @@
 
    <h1 class=p-name>CSS Values and Units Module Level 3</h1>
 
-   <h2 class="no-num no-toc" id=longstatus-date>W3C Candidate Recommendation
-    <span class=dt-updated><span class=value title=20130830>30 August
+   <h2 class="no-num no-toc">W3C Candidate Recommendation <span
+    class=dt-updated><span class=value title=20131008> 8 October
     2013</span></span></h2>
 
    <dl>
     <dt>This version:
 
     <dd><a class=u-url
-     href="http://www.w3.org/TR/2013/CR-css3-values-20130830/">http://www.w3.org/TR/2013/CR-css3-values-20130830/</a>
+     href="http://www.w3.org/TR/2013/CR-css3-values-20131008/">http://www.w3.org/TR/2013/CR-css3-values-20131008/</a>
 
     <dt>Latest version:
 
@@ -428,20 +428,24 @@ <h3 id=component-types><span class=secno>2.1. </span> Component value types</h3>
     class=property>border-width</code>’></var>: the latter is defined as
     the value of the ‘<code class=property>border-width</code>’ property,
     the former requires an explicit expansion elsewhere. The definition of a
-    non-terminal is located near its first appearance in the specification.
+    non-terminal is typically located near its first appearance in the
+    specification.
   </ol>
 
-  <p>Some property value definitions also include the slash (/) and/or the
-   comma (,) as literals. These represent their corresponding tokens.
+  <p> Some property value definitions also include the slash (/), the comma
+   (,), and/or parentheses as literals. These represent their corresponding
+   tokens. Other non-keyword literal characters that may appear in a
+   component value, such as “+”, must be written enclosed in single
+   quotes.
 
-  <p>All CSS properties also accept the <a href="#common-keywords">CSS-wide
+  <p> All CSS properties also accept the <a href="#common-keywords">CSS-wide
    keyword values</a> as the sole component of their property value. For
    readability these are not listed explicitly in the property value syntax
    definitions. For example, the full value definition of <a
    href="http://www.w3.org/TR/css3-background/#border-color">‘<code
-   class=property>border-color</code>’</a> is ‘<code class=css>[
-   &lt;color>{1,4} ] | inherit | initial</code>’ (even though it is listed
-   as ‘<code class=css>&lt;color>{1,4}</code>’).
+   class=property>border-color</code>’</a> is ‘<code
+   class=css>&lt;color>{1,4} | inherit | initial | unset</code>’ (even
+   though it is listed as ‘<code class=css>&lt;color>{1,4}</code>’).
 
   <p class=note> Note: This implies that, in general, combining these
    keywords with other component values in the same declaration results in an
@@ -476,10 +480,6 @@ <h3 id=component-combinators><span class=secno>2.2. </span> Component value
   <pre>
 <!---->  a b   |   c ||   d &&   e f
 <!---->[ a b ] | [ c || [ d && [ e f ]]]</pre>
-  <!--
-	<p>
-		White space is allowed, but optional, between components of a combination.
--->
 
   <h3 id=component-multipliers><span class=secno>2.3. </span> Component value
    multipliers</h3>
@@ -495,20 +495,23 @@ <h3 id=component-multipliers><span class=secno>2.3. </span> Component value
     one or more times.
 
    <li>A question mark (?) indicates that the preceding type, word, or group
-    is optional.
+    is optional (occurs zero or one times).
+
+   <li>A single number in curly braces ({<var>A</var>}) indicates that the
+    preceding type, word, or group occurs <var>A</var> times.
 
-   <li>A pair of numbers in curly braces ({<var>A</var>,<var>B</var>})
-    indicates that the preceding type, word, or group occurs at least
-    <var>A</var> and at most <var>B</var> times.
+   <li>A comma-separated pair of numbers in curly braces
+    ({<var>A</var>,<var>B</var>}) indicates that the preceding type, word, or
+    group occurs at least <var>A</var> and at most <var>B</var> times. The
+    <var>B</var> may be omitted ({<var>A</var>,}) to indicate that there must
+    be at least <var>A</var> repetitions, with no upper bound on the number
+    of repetitions.
 
    <li>A hash mark (#) indicates that the preceding type, word, or group
-    occurs one or more times, separated by comma tokens.
+    occurs one or more times, separated by comma tokens. It may optionally be
+    followed by the curly brace forms, above, to indicate precisely how many
+    times the repetition occurs.
   </ul>
-  <!--
-	<p>
-		White space is allowed, but optional, between repetitions
-		and around the comma separator of ''#''-multiplied lists.
--->
 
   <p>For repeated component values (indicated by ‘<code
    class=css>*</code>’, ‘<code class=css>+</code>’, or ‘<code
@@ -2362,10 +2365,10 @@ <h3 class=no-num id=normative-references>Normative references</h3>
    <dt id=CSS21>[CSS21]
 
    <dd>Bert Bos; et al. <a
-    href="http://www.w3.org/TR/2011/REC-CSS2-20110607"><cite>Cascading Style
+    href="http://www.w3.org/TR/2011/REC-CSS2-20110607/"><cite>Cascading Style
     Sheets Level 2 Revision 1 (CSS 2.1) Specification.</cite></a> 7 June
     2011. W3C Recommendation. URL: <a
-    href="http://www.w3.org/TR/2011/REC-CSS2-20110607">http://www.w3.org/TR/2011/REC-CSS2-20110607</a>
+    href="http://www.w3.org/TR/2011/REC-CSS2-20110607/">http://www.w3.org/TR/2011/REC-CSS2-20110607/</a>
    </dd>
    <!---->
 
@@ -2402,9 +2405,9 @@ <h3 class=no-num id=normative-references>Normative references</h3>
    <dt id=CSS3COLOR>[CSS3COLOR]
 
    <dd>Tantek Çelik; Chris Lilley; L. David Baron. <a
-    href="http://www.w3.org/TR/2011/REC-css3-color-20110607"><cite>CSS Color
+    href="http://www.w3.org/TR/2011/REC-css3-color-20110607/"><cite>CSS Color
     Module Level 3.</cite></a> 7 June 2011. W3C Recommendation. URL: <a
-    href="http://www.w3.org/TR/2011/REC-css3-color-20110607">http://www.w3.org/TR/2011/REC-css3-color-20110607</a>
+    href="http://www.w3.org/TR/2011/REC-css3-color-20110607/">http://www.w3.org/TR/2011/REC-css3-color-20110607/</a>
    </dd>
    <!---->
 

css-values/Overview.src.html

@@ -153,25 +153,33 @@ <h3 id="component-types">
 		<var>&lt;border-width></var> and <var>&lt;'border-width'></var>:
 		the latter is defined as the value of the 'border-width' property,
 		the former requires an explicit expansion elsewhere.
-		The definition of a non-terminal is located near its first appearance
+		The definition of a non-terminal is typically located near its first appearance
 		in the specification.
 	</ol>
 
-	<p>Some property value definitions also include the slash (/) and/or the
-	comma (,) as literals. These represent their corresponding tokens.
+	<p>
+		Some property value definitions also include the slash (/),
+		the comma (,),
+		and/or parentheses as literals.
+		These represent their corresponding tokens.
+		Other non-keyword literal characters that may appear in a component value,
+		such as “+”,
+		must be written enclosed in single quotes.
+
+	<p>
+		All CSS properties also accept the <a href="#common-keywords">CSS-wide keyword values</a>
+		as the sole component of their property value.
+		For readability these are not listed explicitly in the property value syntax definitions.
+		For example, the full value definition of <a href="http://www.w3.org/TR/css3-background/#border-color">'border-color'</a>
+		is ''&lt;color>{1,4} | inherit | initial | unset''
+		(even though it is listed as ''&lt;color>{1,4}'').
 
-	<p>All CSS properties also accept the <a href="#common-keywords">CSS-wide keyword values</a>
-	as the sole component of their property value.
-	For readability these are not listed explicitly in the property value syntax definitions.
-	For example, the full value definition of <a href="http://www.w3.org/TR/css3-background/#border-color">'border-color'</a>
-	is ''[ &lt;color>{1,4} ] | inherit | initial''
-	(even though it is listed as ''&lt;color>{1,4}'').
 	<p class="note">
 		Note: This implies that, in general,
 		combining these keywords with other component values in the same declaration
 		results in an invalid declaration.
 		For example,
-	''background: url(corner.png) no-repeat, inherit;'' is invalid.
+		''background: url(corner.png) no-repeat, inherit;'' is invalid.
 
 <h3 id="component-combinators">
 Component value combinators</h3>
@@ -197,11 +205,6 @@ <h3 id="component-combinators">
 <!---->  a b   |   c ||   d &&   e f
 <!---->[ a b ] | [ c || [ d && [ e f ]]]</pre>
 
-<!--
-	<p>
-		White space is allowed, but optional, between components of a combination.
--->
-
 <h3 id="component-multipliers">
 Component value multipliers</h3>
 
@@ -210,28 +213,30 @@ <h3 id="component-multipliers">
 
 	<ul>
 		<li>An asterisk (*) indicates that the preceding type, word, or
-		group occurs zero or more times.
+			group occurs zero or more times.
 
 		<li>A plus (+) indicates that the preceding type, word, or group
-		occurs one or more times.
+			occurs one or more times.
 
 		<li>A question mark (?) indicates that the preceding type, word, or
-		group is optional.
+			group is optional (occurs zero or one times).
+
+		<li>A single number in curly braces ({<var>A</var>})
+			indicates that the preceding type, word, or group occurs <var>A</var> times.
 
-		<li>A pair of numbers in curly braces ({<var>A</var>,<var>B</var>})
-		indicates that the preceding type, word, or group occurs at least
-		<var>A</var> and at most <var>B</var> times.
+		<li>A comma-separated pair of numbers in curly braces ({<var>A</var>,<var>B</var>})
+			indicates that the preceding type, word, or group occurs at least
+			<var>A</var> and at most <var>B</var> times.
+			The <var>B</var> may be omitted ({<var>A</var>,})
+			to indicate that there must be at least <var>A</var> repetitions,
+			with no upper bound on the number of repetitions.
 
 		<li>A hash mark (#) indicates that the preceding type, word, or
-		group occurs one or more times, separated by comma tokens.
+			group occurs one or more times, separated by comma tokens.
+			It may optionally be followed by the curly brace forms, above,
+			to indicate precisely how many times the repetition occurs.
 	</ul>
 
-<!--
-	<p>
-		White space is allowed, but optional, between repetitions
-		and around the comma separator of ''#''-multiplied lists.
--->
-
 	<p>For repeated component values (indicated by ''*'', ''+'', or ''#''), UAs must support at least 20 repetitions of the component.  If a property value contains more than the supported number of repetitions, the declaration must be ignored as if it were invalid.</p>
 
 <h3 id="component-whitespace">