Grammar fixes to allow attr() inside calc(), and to fix unary operator issue.

Author: fantasai

css3-values/Overview.html

@@ -1334,6 +1334,11 @@ <h3 id=calc-notation><span class=secno>8.1. </span> Mathematical
    href="#time-value"><var>&lt;time></var></a>, <a
    href="#number-value"><var>&lt;number></var></a>, or <a
    href="#integer-value"><var>&lt;integer></var></a> values are allowed.
+   Components of a ‘<a href="#calc"><code class=css>calc()</code></a>’
+   expression can be literal values, ‘<a href="#attr"><code
+   class=css>attr()</code></a>’ expressions, or <a
+   href="#percentage-value"><var>&lt;percentage></var></a> values that
+   resolve to one of the preceding types.
 
   <p> The computed value of a calc() expression is the expression with all
    components computed, with all multiplication/division subexpressions
@@ -1420,8 +1425,9 @@ <h4 id=calc-syntax><span class=secno>8.1.1. </span> Syntax</h4>
 math    : calc S*;
 calc    : "calc(" S* sum S* ")";
 sum     : product [ S+ [ "+" | "-" ] S+ product ]*;
-product : unit [ S* [ "*" | "/" ] S* unit ]*;
-unit    : ["+"|"-"]? [ NUMBER | DIMENSION | PERCENTAGE | "(" S* sum S* ")" ];</pre>
+product : unit [ S* [ "*" S* unit | "/" S* NUMBER ] ]*;
+attr    : "attr(" S* wqname [ S+ type-keyword ]? S* [ "," [ unit | calc ] S* ]? ")";
+unit    : [ NUMBER | DIMENSION | PERCENTAGE | "(" S* sum S* ")" | attr ];</pre>
 
   <p class=note>Note that the grammar requires spaces around binary ‘<code
    class=css>+</code>’ and ‘<code class=css>-</code>’ operators. The
@@ -1463,12 +1469,15 @@ <h4 id=calc-type-checking><span class=secno>8.1.2. </span> Type Checking</h4>
    href="#resolved-type"><i>resolved type</i></a> of the expression is
    determined by the types of the values it contains. <a
    href="#number"><code>NUMBER</code></a> tokens are of type <a
-   href="#number-value"><var>&lt;number></var></a>. A <a
+   href="#number-value"><var>&lt;number></var></a> or <a
+   href="#integer-value"><var>&lt;integer></var></a>. A <a
    href="#dimension"><code>DIMENSION</code></a> token's type is given by its
    unit (‘<code class=css>cm</code>’ is <a
    href="#length-value"><var>&lt;length></var></a>, ‘<a href="#deg"><code
    class=css>deg</code></a>’ is <a
-   href="#angle-value"><var>&lt;angle></var></a>, etc.). If percentages are
+   href="#angle-value"><var>&lt;angle></var></a>, etc.). An ‘<a
+   href="#attr"><code class=css>attr()</code></a>’ expression's type is
+   given by its <var>&lt;type-or-unit></var> argument. If percentages are
    accepted in the context in which the expression is placed, a <a
    href="#percentage"><code>PERCENTAGE</code></a> token has the type of the
    value that percentages are relative to; otherwise, a math expression

css3-values/Overview.src.html

@@ -892,7 +892,10 @@ <h3 id="calc-notation">
 	<var>&lt;time></var>,
 	<var>&lt;number></var>, or
 	<var>&lt;integer></var>
-	values are allowed.</p>
+	values are allowed.
+	Components of a ''calc()'' expression can be literal values,
+	''attr()'' expressions, or <var>&lt;percentage></var> values
+	that resolve to one of the preceding types.
 
 	<p>
 		The computed value of a calc() expression is the expression
@@ -982,8 +985,9 @@ <h4 id='calc-syntax'>
 math    : calc S*;
 calc    : "calc(" S* sum S* ")";
 sum     : product [ S+ [ "+" | "-" ] S+ product ]*;
-product : unit [ S* [ "*" | "/" ] S* unit ]*;
-unit    : ["+"|"-"]? [ NUMBER | DIMENSION | PERCENTAGE | "(" S* sum S* ")" ];</pre>
+product : unit [ S* [ "*" S* unit | "/" S* NUMBER ] ]*;
+attr    : "attr(" S* wqname [ S+ type-keyword ]? S* [ "," [ unit | calc ] S* ]? ")";
+unit    : [ NUMBER | DIMENSION | PERCENTAGE | "(" S* sum S* ")" | attr ];</pre>
 
 	<p class='note'>Note that the grammar requires spaces around binary ''+'' 
 	and ''-'' operators.  The ''*'' and ''/'' operators do not require 
@@ -1021,9 +1025,10 @@ <h4 id='calc-type-checking'>
 		The <i>resolved type</i> must be valid for where the expression is placed; 
 		otherwise, the expression is invalid. 
 		The <i>resolved type</i> of the expression is determined by the types of the values it contains. 
-		<code>NUMBER</code> tokens are of type <var>&lt;number></var>. 
+		<code>NUMBER</code> tokens are of type <var>&lt;number></var> or <var>&lt;integer></var>.
 		A <code>DIMENSION</code> token's type is given by its unit 
-		(''cm'' is <var>&lt;length></var>, ''deg'' is <var>&lt;angle></var>, etc.). 
+		(''cm'' is <var>&lt;length></var>, ''deg'' is <var>&lt;angle></var>, etc.).
+		An ''attr()'' expression's type is given by its <var>&lt;type-or-unit></var> argument.
 		If percentages are accepted in the context in which the expression is placed, 
 		a <code>PERCENTAGE</code> token has the type of the value that percentages are relative to; 
 		otherwise,