[css-syntax] Drop the digit when serializating an+b with A=1 or -1. Fixes w3c#1504. Also update the link-defaults.

Author: tabatkins

css-syntax/Overview.bs

@@ -16,7 +16,13 @@ Editor: Simon Sapin, Mozilla, http://exyr.org/about/
 Abstract: This module describes, in general terms, the basic structure and syntax of CSS stylesheets. It defines, in detail, the syntax and parsing of CSS - how to turn a stream of bytes into a meaningful stylesheet.
 Ignored Terms: <keyframes-name>, <keyframe-rule>, <keyframe-selector>, <translation-value>, <media-query-list>, <unicode-range-token>
 Ignored Vars: +b, -b, foo
-Link Defaults: css-text-decor-3 (property) text-decoration, css-color-3 (property) color, css-transforms-1 (function) translatex()
+</pre>
+
+<pre class=link-defaults>
+spec:css-text-decor-3; type:property; text:text-decoration
+spec:css-color-3; type:property; text:color
+spec:css-transforms-1; type:function; text:translatex()
+spec:infra; type:dfn; text:string
 </pre>
 
 <h2 id="intro">
@@ -3333,33 +3339,41 @@ Serialization</h2>
 <h3 id='serializing-anb'>
 Serializing <var>&lt;an+b></var></h3>
 
-	To <dfn export>serialize an <var>&lt;an+b></var> value</dfn>,
-	let <var>s</var> initially be the empty string:
+	<div algorithm>
+		To <dfn export>serialize an <<an+b>> value</dfn>,
+		with integer values |A| and |B|:
 
-	<dl>
-		<dt><var>A</var> and <var>B</var> are both zero
-		<dd>
-			Append "0" to <var>s</var>.
+		1. If |A| is zero,
+			return the serialization of |B|.
 
-		<dt><var>A</var> is zero, <var>B</var> is non-zero
-		<dd>
-			Serialize <var>B</var> and append it to <var>s</var>.
+		2. Otherwise, let |result| initially be an empty [=string=].
 
-		<dt><var>A</var> is non-zero, <var>B</var> is zero
-		<dd>
-			Serialize <var>A</var> and append it to <var>s</var>.
-			Append "n" to <var>s</var>.
+		3.
+			<dl class=switch>
+				: |A| is <code>1</code>
+				:: Append "n" to |result|.
 
-		<dt><var>A</var> and <var>B</var> are both non-zero
-		<dd>
-			Serialize <var>A</var> and append it to <var>s</var>.
-			Append "n" to <var>s</var>.
-			If <var>B</var> is positive,
-			append "+" to <var>s</var>
-			Serialize <var>B</var> and append it to <var>s</var>.
-	</dl>
+				: |A| is <code>-1</code>
+				:: Append "-n" to |result|.
+
+				: |A| is non-zero
+				:: Serialize |A| and append it to |result|,
+					then append "n" to |result|.
+			</dl>
+
+		4.
+			<dl class=switch>
+				: |B| is greater than zero
+				:: Append "+" to |result|,
+					then append the serialization of |B| to |result|.
+
+				: |B| is less than zero
+				:: Append the serialization of |B| to |result|.
+			</dl>
+
+		5. Return |result|.
+	</div>
 
-	Return <var>s</var>.
 
 <h2 id="priv-sec">
 Privacy and Security Considerations</h2>