[css-values-5] Update the cache specifics to the new semantics. Add issue for pseudo-elements.

Author: tabatkins

css-values-5/Overview.bs

@@ -2854,31 +2854,24 @@ Sharing (Or Not) Random Values: the <<random-cache-key>> value</h3>
 	* A [=random cache name=] is a [=tuple=] of:
 		1. A nullable [=string=] name:
 			the value of the <<dashed-ident>>, if specified;
-			otherwise <code>"auto"</code> if ''random()/auto'' is specified
-			or the <<random-cache-key>> is omitted;
 			otherwise null.
-		2. A nullable [=string=] property name:
-			the name of the property the [=random function=] is used in
-			(<em>before</em> shorthand expansion)
-			if ''random()/property'' or ''random()/auto'' is specified;
-			otherwise null.
-		3. A nullable [=integer=] index:
-			the index of the [=random function=]
-			among other [=random functions=] in the same property value,
-			if ''random()/index'' or ''random()/auto'' is specified;
+		2. A nullable [=string=] property/index value:
+			the value of the <<random-ua-ident>>, if specified/calculated;
 			otherwise null.
 		4. A nullable "element identifier"
 			uniquely identifying the {{Element}} or [=pseudo-element=]
 			the style is being applied to,
-			if ''random()/element'' or ''random()/auto'' is specified;
+			if ''random()/element-scoped'' is specified;
 			otherwise null.
 		5. A document ID identifying the {{Document}} the styles are from.
 
-		The "element ID" and "document ID" must have the same lifetimes and equivalence
+		The "element ID" and "document ID" must have the same lifetimes and equivalence semantics
 		as a JavaScript reference to the {{Element}} or {{Document}}.
 
+		Issue: The behavior for pseudo-elements needs to be clarified.
+
 	* The [=random cache name=] and [=random base value=]
-		must be determined at [=computed value=] time,
+		must be determined by [=computed value=] time,
 		before [=inheritance=],
 		so that a random function which is unresolved by inheritance time
 		(due to containing, for example, a layout-sensitive percentage)
@@ -2892,14 +2885,13 @@ Sharing (Or Not) Random Values: the <<random-cache-key>> value</h3>
 		For example:
 
 		<pre highlight=css>
-		.same-tb-and-rl {
+		.same-tb-same-rl {
 			margin: random(0px, 10px) random(0px, 10px);
 		}
 		</pre>
 
-		Here, the "property name" and "index"  in the [=random cache names=]
-		is <code>"margin"</code> and <code>0</code> for the first instance
-		and <code>"margin"</code> and <code>1</code> for the second.
+		Here, the <<random-ua-ident>> part of the [=random cache name=]
+		is "ua-margin-1" and "ua-margin-2", respectively.
 		After expansion, then,
 		'margin-top' and 'margin-bottom' will share the same random value,
 		and 'margin-left' and 'margin-right' will share a different random value.
@@ -2913,12 +2905,12 @@ Sharing (Or Not) Random Values: the <<random-cache-key>> value</h3>
 		}
 		</pre>
 
-		The 'margin-bottom' value has a [=random cache name=] "property name"
-		of <code>"margin-bottom"</code>,
-		which is different from the 'margin-top' key of <code>"margin"</code>,
+		The 'margin-bottom' value has a [=random cache name=] <<random-ua-ident>>
+		of <code>"ua-margin-bottom-1"</code>,
+		which is different from the 'margin-top' key of <code>"ua-margin-1"</code>,
 		so the top and bottom margins will be different random values.
-		'margin-left' and 'margin-right' continue to share a third random value,
-		as they still share the name <code>"margin"</code> property name and <code>1</code> index.
+		'margin-left' and 'margin-right' continue to share a third random value <code>"ua-margin-2"</code>,
+		as they still share the name <code>"margin"</code> property name and <code>2</code> index.
 	</div>
 
 	<div class=example>
@@ -2941,14 +2933,13 @@ Sharing (Or Not) Random Values: the <<random-cache-key>> value</h3>
 		the ''random()'' function isn't evaluated
 		(or even recognized *as* a ''random()'' function)
 		in ''--size'',
-		so the default rules for an omitted <<dashed-ident>>
-		in the <<random-cache-key>> isn't applied.
+		so the default rules for an omitted <<random-cache-key>> aren't applied.
 		Instead, it's evaluated when it's substituted into 'width' and 'height',
 		so each gets a distinct [=random cache name=],
 		and this ends up defining a random <em>rectangle</em>,
 		rather than a square.
 
-		Similarly, ''random()/element'' in the <<random-cache-key>>
+		Similarly, ''random()/element-scoped'' in the <<random-cache-key>>
 		won't cause the function to determine its "element identifier"
 		until substitution actually happens,
 		which might be <em>after</em> '--size' has inherited through multiple elements,
@@ -2964,7 +2955,8 @@ Sharing (Or Not) Random Values: the <<random-cache-key>> value</h3>
 		Both issues can be resolved
 		by instead using a [=registered custom property=]
 		with a non-universal grammar,
-		so the ''random()'' function will be parsed and evaluated in the [=custom property=],
+		so the ''random()'' function will be parsed and evaluated in the [=custom property=]
+		(gaining a <<random-ua-ident>> of "ua---size-1"),
 		and then the resolved random value will be substituted into each property.
 	</div>
 
@@ -3010,8 +3002,8 @@ Simplification</h4>
 		even if you read and then set the value back.
 	</div>
 
-	The [=random base value=] of a [=random function=] is known at [=specified value=] time,
-	at the latest,
+	The [=random base value=] of a [=random function=]
+	is generally known at [=specified value=] time,
 	once it's known which element the function is being applied to.
 	As a [=math function=], a ''random()'' function can be [=simplify a calculation tree|simplified=]
 	as soon as its argument [=calculations=]