rustdoc: don't generate DOM element for operator

In our source page highlighting, we were generating `<span class="op">`
tags for all "operators", including e.g. `<` `>` around generic
parameters, `*`, `&`. This contributed significantly to DOM size, but
we don't actually style `.op` except in the ayu theme.

Remove the styles for `.op` in ayu, and stop generating the `<span>`s.

This reduces DOM size of an example page[1] from 265,938 HTML elements
to 242,165 elements, a 9% reduction.

[1]:
https://doc.rust-lang.org/nightly/src/core/up/up/stdarch/crates/core_arch/src/x86/avx512f.rs.html

src/librustdoc/html/highlight.rs

@@ -133,7 +133,6 @@ enum Class {
     // Keywords that do pointer/reference stuff.
     RefKeyWord,
     Self_(Span),
-    Op,
     Macro(Span),
     MacroNonTerminal,
     String,
@@ -157,7 +156,6 @@ impl Class {
             Class::KeyWord => "kw",
             Class::RefKeyWord => "kw-2",
             Class::Self_(_) => "self",
-            Class::Op => "op",
             Class::Macro(_) => "macro",
             Class::MacroNonTerminal => "macro-nonterminal",
             Class::String => "string",
@@ -182,7 +180,6 @@ impl Class {
             | Self::Attribute
             | Self::KeyWord
             | Self::RefKeyWord
-            | Self::Op
             | Self::MacroNonTerminal
             | Self::String
             | Self::Number
@@ -494,7 +491,7 @@ impl<'a> Classifier<'a> {
             // or a reference or pointer type. Unless, of course, it looks like
             // a logical and or a multiplication operator: `&&` or `* `.
             TokenKind::Star => match self.tokens.peek() {
-                Some((TokenKind::Whitespace, _)) => Class::Op,
+                Some((TokenKind::Whitespace, _)) => return no_highlight(sink),
                 Some((TokenKind::Ident, "mut")) => {
                     self.next();
                     sink(Highlight::Token { text: "*mut", class: Some(Class::RefKeyWord) });
@@ -510,15 +507,15 @@ impl<'a> Classifier<'a> {
             TokenKind::And => match self.tokens.peek() {
                 Some((TokenKind::And, _)) => {
                     self.next();
-                    sink(Highlight::Token { text: "&&", class: Some(Class::Op) });
+                    sink(Highlight::Token { text: "&&", class: None });
                     return;
                 }
                 Some((TokenKind::Eq, _)) => {
                     self.next();
-                    sink(Highlight::Token { text: "&=", class: Some(Class::Op) });
+                    sink(Highlight::Token { text: "&=", class: None });
                     return;
                 }
-                Some((TokenKind::Whitespace, _)) => Class::Op,
+                Some((TokenKind::Whitespace, _)) => return no_highlight(sink),
                 Some((TokenKind::Ident, "mut")) => {
                     self.next();
                     sink(Highlight::Token { text: "&mut", class: Some(Class::RefKeyWord) });
@@ -531,7 +528,7 @@ impl<'a> Classifier<'a> {
             TokenKind::Eq => match lookahead {
                 Some(TokenKind::Eq) => {
                     self.next();
-                    sink(Highlight::Token { text: "==", class: Some(Class::Op) });
+                    sink(Highlight::Token { text: "==", class: None });
                     return;
                 }
                 Some(TokenKind::Gt) => {
@@ -539,7 +536,7 @@ impl<'a> Classifier<'a> {
                     sink(Highlight::Token { text: "=>", class: None });
                     return;
                 }
-                _ => Class::Op,
+                _ => return no_highlight(sink),
             },
             TokenKind::Minus if lookahead == Some(TokenKind::Gt) => {
                 self.next();
@@ -556,7 +553,7 @@ impl<'a> Classifier<'a> {
             | TokenKind::Percent
             | TokenKind::Bang
             | TokenKind::Lt
-            | TokenKind::Gt => Class::Op,
+            | TokenKind::Gt => return no_highlight(sink),
 
             // Miscellaneous, no highlighting.
             TokenKind::Dot

src/librustdoc/html/highlight/fixtures/decorations.html

@@ -1,2 +1,2 @@
-<span class="example"><span class="kw">let</span> <span class="ident">x</span> <span class="op">=</span> <span class="number">1</span>;</span>
-<span class="kw">let</span> <span class="ident">y</span> <span class="op">=</span> <span class="number">2</span>;
+<span class="example"><span class="kw">let</span> <span class="ident">x</span> = <span class="number">1</span>;</span>
+<span class="kw">let</span> <span class="ident">y</span> = <span class="number">2</span>;

src/librustdoc/html/highlight/fixtures/highlight.html

@@ -1,4 +1,4 @@
 <span class="kw">use</span> <span class="ident"><span class="kw">crate</span>::a::foo</span>;
 <span class="kw">use</span> <span class="ident"><span class="self">self</span>::whatever</span>;
-<span class="kw">let</span> <span class="ident">x</span> <span class="op">=</span> <span class="ident"><span class="kw">super</span>::b::foo</span>;
-<span class="kw">let</span> <span class="ident">y</span> <span class="op">=</span> <span class="ident"><span class="self">Self</span>::whatever</span>;
+<span class="kw">let</span> <span class="ident">x</span> = <span class="ident"><span class="kw">super</span>::b::foo</span>;
+<span class="kw">let</span> <span class="ident">y</span> = <span class="ident"><span class="self">Self</span>::whatever</span>;

src/librustdoc/html/highlight/fixtures/sample.html

@@ -8,23 +8,23 @@
 .lifetime { color: #B76514; }
 .question-mark { color: #ff9011; }
 </style>
-<pre><code><span class="attribute">#![<span class="ident">crate_type</span> <span class="op">=</span> <span class="string">&quot;lib&quot;</span>]</span>
+<pre><code><span class="attribute">#![<span class="ident">crate_type</span> = <span class="string">&quot;lib&quot;</span>]</span>
 
 <span class="kw">use</span> <span class="ident">std::path</span>::{<span class="ident">Path</span>, <span class="ident">PathBuf</span>};
 
-<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">&quot;linux&quot;</span>)]</span>
+<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">target_os</span> = <span class="string">&quot;linux&quot;</span>)]</span>
 <span class="kw">fn</span> <span class="ident">main</span>() -&gt; () {
-    <span class="kw">let</span> <span class="ident">foo</span> <span class="op">=</span> <span class="bool-val">true</span> <span class="op">&amp;&amp;</span> <span class="bool-val">false</span> <span class="op">|</span><span class="op">|</span> <span class="bool-val">true</span>;
-    <span class="kw">let</span> <span class="kw">_</span>: <span class="kw-2">*const</span> () <span class="op">=</span> <span class="number">0</span>;
-    <span class="kw">let</span> <span class="kw">_</span> <span class="op">=</span> <span class="kw-2">&amp;</span><span class="ident">foo</span>;
-    <span class="kw">let</span> <span class="kw">_</span> <span class="op">=</span> <span class="op">&amp;&amp;</span><span class="ident">foo</span>;
-    <span class="kw">let</span> <span class="kw">_</span> <span class="op">=</span> <span class="kw-2">*</span><span class="ident">foo</span>;
+    <span class="kw">let</span> <span class="ident">foo</span> = <span class="bool-val">true</span> &amp;&amp; <span class="bool-val">false</span> || <span class="bool-val">true</span>;
+    <span class="kw">let</span> <span class="kw">_</span>: <span class="kw-2">*const</span> () = <span class="number">0</span>;
+    <span class="kw">let</span> <span class="kw">_</span> = <span class="kw-2">&amp;</span><span class="ident">foo</span>;
+    <span class="kw">let</span> <span class="kw">_</span> = &amp;&amp;<span class="ident">foo</span>;
+    <span class="kw">let</span> <span class="kw">_</span> = <span class="kw-2">*</span><span class="ident">foo</span>;
     <span class="macro">mac!</span>(<span class="ident">foo</span>, <span class="kw-2">&amp;mut</span> <span class="ident">bar</span>);
-    <span class="macro">assert!</span>(<span class="self">self</span>.<span class="ident">length</span> <span class="op">&lt;</span> <span class="ident">N</span> <span class="op">&amp;&amp;</span> <span class="ident">index</span> <span class="op">&lt;</span><span class="op">=</span> <span class="self">self</span>.<span class="ident">length</span>);
+    <span class="macro">assert!</span>(<span class="self">self</span>.<span class="ident">length</span> &lt; <span class="ident">N</span> &amp;&amp; <span class="ident">index</span> &lt;= <span class="self">self</span>.<span class="ident">length</span>);
     <span class="ident">::std::env::var</span>(<span class="string">&quot;gateau&quot;</span>).<span class="ident">is_ok</span>();
     <span class="attribute">#[<span class="ident">rustfmt::skip</span>]</span>
-    <span class="kw">let</span> <span class="ident">s</span>:<span class="ident">std::path::PathBuf</span> <span class="op">=</span> <span class="ident">std::path::PathBuf::new</span>();
-    <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">s</span> <span class="op">=</span> <span class="ident">String::new</span>();
+    <span class="kw">let</span> <span class="ident">s</span>:<span class="ident">std::path::PathBuf</span> = <span class="ident">std::path::PathBuf::new</span>();
+    <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">s</span> = <span class="ident">String::new</span>();
 
     <span class="kw">match</span> <span class="kw-2">&amp;</span><span class="ident">s</span> {
         <span class="kw-2">ref</span> <span class="kw-2">mut</span> <span class="ident">x</span> =&gt; {}

src/librustdoc/html/highlight/fixtures/union.html

@@ -4,5 +4,5 @@
 }
 
 <span class="kw">fn</span> <span class="ident">main</span>() {
-    <span class="kw">let</span> <span class="ident">union</span> <span class="op">=</span> <span class="number">0</span>;
+    <span class="kw">let</span> <span class="ident">union</span> = <span class="number">0</span>;
 }

src/librustdoc/html/static/css/themes/ayu.css

@@ -239,7 +239,7 @@ details.rustdoc-toggle > summary::before {
 pre.rust .number, pre.rust .string { color: #b8cc52; }
 pre.rust .kw, pre.rust .kw-2, pre.rust .prelude-ty,
 pre.rust .bool-val, pre.rust .prelude-val,
-pre.rust .op, pre.rust .lifetime { color: #ff7733; }
+pre.rust .lifetime { color: #ff7733; }
 pre.rust .macro, pre.rust .macro-nonterminal { color: #a37acc; }
 pre.rust .question-mark {
 	color: #ff9011;
@@ -251,7 +251,7 @@ pre.rust .self {
 pre.rust .attribute {
 	color: #e6e1cf;
 }
-pre.rust .attribute .ident, pre.rust .attribute .op {
+pre.rust .attribute .ident {
 	color: #e6e1cf;
 }
 

src/test/rustdoc/macro_rules-matchers.rs

@@ -6,16 +6,13 @@
 // @has 'foo/macro.todo.html'
 // @has - '//span[@class="macro"]' 'macro_rules!'
 // @has - '//span[@class="ident"]' 'todo'
-// Note: the only op is the `+`
-// @count - '//pre[@class="rust macro"]//span[@class="op"]' 1
 
 // @has - '{ () => { ... }; ($('
 // @has - '//span[@class="macro-nonterminal"]' '$'
 // @has - '//span[@class="macro-nonterminal"]' 'arg'
 // @has - ':'
 // @has - '//span[@class="ident"]' 'tt'
-// @has - '),'
-// @has - '//span[@class="op"]' '+'
+// @has - ')+'
 // @has - ') => { ... }; }'
 pub use std::todo;