[selectors-4] Clean up terminology section per glazou's recommendations. w3c#2240

Author: fantasai

selectors-4/Overview.bs

@@ -17,7 +17,7 @@ Former Editor: Daniel Glazman
 Former Editor: Ian Hickson
 Former Editor: Peter Linss
 Former Editor: John Williams
-Abstract: <b>Selectors</b> are patterns that match against elements in a tree, and as such form one of several technologies that can be used to select nodes in a document. Selectors have been optimized for use with HTML and XML, and are designed to be usable in performance-critical code. They are a core component of <abbr title="Cascading Style Sheets">CSS</abbr> (Cascading Style Sheets), which uses Selectors to bind style properties to elements in the docu	ment.
+Abstract: <a>Selectors</a> are patterns that match against elements in a tree, and as such form one of several technologies that can be used to select nodes in a document. Selectors have been optimized for use with HTML and XML, and are designed to be usable in performance-critical code. They are a core component of <abbr title="Cascading Style Sheets">CSS</abbr> (Cascading Style Sheets), which uses Selectors to bind style properties to elements in the docu	ment.
 Abstract: Selectors Level 4 describes the selectors that already exist in [[!SELECT]], and further introduces new selectors for CSS and other languages that may need them.
 At Risk: the column combinator
 At Risk: the '':drop()'' pseudo-class
@@ -40,7 +40,7 @@ Introduction</h2>
 
 	<em>This section is not normative.</em>
 
-	A <dfn>selector</dfn> is a boolean predicate
+	A <a>selector</a> is a boolean predicate
 	that takes an element in a tree structure
 	and tests whether the element matches the selector or not.
 
@@ -538,11 +538,16 @@ Selector Syntax and Structure</h2>
 <h3 id="structure">
 Structure and Terminology</h3>
 
+	A <dfn>selector</dfn> represents
+	a particular pattern of element(s) in a tree structure.
 	The term <a>selector</a> can refer to a <a>simple selector</a>,
 	<a>compound selector</a>, <a>complex selector</a>, or <a>selector list</a>.
+	The <dfn export for=selector lt="subject|subject of a selector">subject of a selector</dfn> is
+	any element that selector is defined to be about;
+	that is, any element <dfn export lt="match">matching</dfn> that <a>selector</a>.
 
 	A <dfn id="simple" export>simple selector</dfn>
-	represents an element matched by a particular aspect.
+	is a single condition on an element.
 	A <a>type selector</a>,
 	<a>universal selector</a>,
 	<a>attribute selector</a>,
@@ -552,35 +557,59 @@ Structure and Terminology</h3>
 	is a <a>simple selector</a>.
 	It is represented by <<simple-selector>>
 	in the selectors <a href="#grammar">grammar</a>.
+	A given element is said to <a>match</a> a <a>simple selector</a>
+	when that <a>simple selector</a>,
+	as defined in this specification and in accordance with the <a>document language</a>,
+	accurately describes the element.
 
 	A <dfn id="compound" export>compound selector</dfn>
 	is a sequence of <a>simple selectors</a>
-	that are not separated by a <a>combinator</a>.
-	It represents an element that matches all of the <a>simple selectors</a> it contains.
+	that are not separated by a <a>combinator</a>,
+	and represents a set of simultaneous conditions on a single element.
 	If it contains a <a>type selector</a> or <a>universal selector</a>,
 	that selector must come first in the sequence.
 	Only one type selector or universal selector is allowed in the sequence.
 	A <a>compound selector</a> is represented by <<compound-selector>>
 	in the selectors <a href="#grammar">grammar</a>.
+	A given element is said to <a>match</a> a <a>compound selector</a>
+	when it matches all <a>simple selectors</a> in the <a>compound selector</a>.
 
 	Note: As whitespace represents the <a>descendant combinator</a>,
 	no whitespace is allowed between the <a>simple selectors</a>
 	in a <a>compound selector</a>.
 
+	A <dfn export for=selector>combinator</dfn>
+	is a condition of relationship between two elements
+	represented by the <a>compound selectors</a> on either side.
+	Combinators in Selectors Level 4 include:
+	the <a>descendant combinator</a> (white space),
+	the <a>child combinator</a> (U+003E, <code>></code>),
+	the <a>next-sibling combinator</a> (U+002B, <code>+</code>),
+	and the <a>subsequent-sibling combinator</a> (U+007E, <code>~</code>).
+	Two given elements are said to <a>match</a> a <a>combinator</a>
+	when the condition of relationship between these elements is true.
+
 	A <dfn id="complex" export>complex selector</dfn> is
 	a sequence of one or more <a>compound selectors</a>
 	separated by <a>combinators</a>.
-	It represents an element in a particular relationship to other elements.
+	It represents a set of simultaneous conditions
+	on a set of elements in the particular relationships
+	described by its <a>combinators</a>.
 	Complex selectors are represented by <<complex-selector>>
 	in the selectors <a href="#grammar">grammar</a>.
-
-	A <dfn export for=selector>combinator</dfn> represents a particular kind of relationship
-	between the elements matched by the <a>compound selectors</a> on either side.
-	Combinators in Selectors level 4 include:
-	the <a>descendant combinator</a> (white space),
-	the <a>child combinator</a> (U+003E, <code>></code>),
-	the <a>next-sibling combinator</a> (U+002B, <code>+</code>),
-	and the <a>subsequent-sibling combinator</a> (U+007E, <code>~</code>).
+	A given element is said to <a>match</a> a <a>complex selector</a>
+	when there exists a list of elements,
+	each matching a corresponding <a>compound selector</a> in the <a>complex selector</a>,
+	with their relationships matching the <a>combinators</a> between them,
+	and with the given element matching the last <a>compound selector</a>.
+
+	Note: Thus, a selector consisting of a single <a>compound selector</a>
+	matches any element satisfying the requirements
+	of its constituent <a>simple selectors</a>.
+	Prepending another <a>compound selector</a> and a <a>combinator</a>
+	to a sequence imposes additional matching constraints,
+	such that the <a>subjects</a> of a <a>complex selector</a> are always
+	a subset of the elements represented by its last <a>compound selector</a>.
 
 	A <dfn export lt="list of simple selectors|list of compound selectors|list of complex selectors">list of simple/compound/complex selectors</dfn>
 	is a comma-separated list of
@@ -591,34 +620,15 @@ Structure and Terminology</h3>
 	when the type is either unimportant or specified in the surrounding prose;
 	if the type is important and unspecified,
 	it defaults to meaning a <a>list of complex selectors</a>.
-	See [[#grouping]] for further details on <a>selector lists</a>
-	and the various <<*-selector-list>> productions in the <a href="#grammar">grammar</a>.
-
-	The <dfn export for=selector lt="subject|subject of a selector">subject of a selector</dfn> is
-	the element(s) that selector is defined to be about:
-
-	<ul>
-		<li>For a <a>simple selector</a>, it is any element represented by that selector.
-		<li>For a <a>compound selector</a>, it is any element that matches all of its composite <a>simple selectors</a>.
-		<li>For a <a>complex selector</a>, it is any element that matches the last <a>compound selector</a> in the selector.
-		<li>For a <a>selector list</a>, it is any element that matches any of the <a>selectors</a> in the list.
-	</ul>
-
-	An element is said to <dfn for=selector export>match</dfn> a selector
-	if it is a <a>subject</a> of that selector.
-	Thus a selector consisting of a single <a>compound selector</a>
-	matches any element satisfying its requirements.
-	Prepending another <a>compound selector</a> and a <a>combinator</a>
-	to a sequence imposes additional matching constraints,
-	so the <a>subjects</a> of a <a>complex selector</a> are always a subset of
-	the elements represented by its last <a>compound selector</a>.
-
-	Issue: Can we make this less wishy-washy by saying that a complex selector “represents” its last compound selector?
-	Or do we need to have ''a + b'' “represent” both an "a" and a "b" in a sibling relationship?
+	See [[#grouping]] for additional information on <a>selector lists</a>
+	and the various <<*-selector-list>> productions in the <a href="#grammar">grammar</a>
+	for their formal syntax.
+	A given element is said to <a>match</a> a <a>selector list</a>
+	when it matches any (at least one) of the <a>selectors</a>
+	in that <a>selector list</a>.
 
 	Issue: Pseudo-elements aren't handled here, and should be.
 
-
 <h3 id='data-model'>
 Data Model</h3>