Add line numbers option to rustdoc

src/librustdoc/html/highlight.rs

@@ -28,9 +28,12 @@
 use syntax_pos::{Span, FileName};
 
 /// Highlights `src`, returning the HTML output.
-pub fn render_with_highlighting(src: &str, class: Option<&str>,
-                                extension: Option<&str>,
-                                tooltip: Option<(&str, &str)>) -> String {
+pub fn render_with_highlighting(
+    src: &str,
+    class: Option<&str>,
+    extension: Option<&str>,
+    tooltip: Option<(&str, &str)>,
+) -> String {
     debug!("highlighting: ================\n{}\n==============", src);
     let sess = parse::ParseSess::new(FilePathMapping::empty());
     let fm = sess.source_map().new_source_file(FileName::Custom("stdin".to_string()),
@@ -373,9 +376,9 @@ fn rustdoc_class(self) -> &'static str {
 }
 
 fn write_header(class: Option<&str>, out: &mut dyn Write) -> io::Result<()> {
-    write!(out, "<pre class=\"rust {}\">\n", class.unwrap_or(""))
+    write!(out, "<div class=\"example-wrap\"><pre class=\"rust {}\">\n", class.unwrap_or(""))
 }
 
 fn write_footer(out: &mut dyn Write) -> io::Result<()> {
-    write!(out, "</pre>\n")
+    write!(out, "</pre></div>\n")
 }

src/librustdoc/html/render.rs

@@ -1709,6 +1709,7 @@ pub fn new(root_path: &'a str, suffix: &'a str) -> Settings<'a> {
                 ("method-docs", "Auto-hide item methods' documentation", false),
                 ("go-to-only-result", "Directly go to item in search if there is only one result",
                  false),
+                ("line-numbers", "Show line numbers on code examples", false),
             ],
             root_path,
             suffix,

src/librustdoc/html/static/main.js

@@ -2093,6 +2093,7 @@
         return wrapper;
     }
 
+    var hideItemDeclarations = getCurrentValue('rustdoc-item-declarations') === "false";
     onEach(document.getElementsByClassName('docblock'), function(e) {
         if (hasClass(e, 'autohide')) {
             var wrap = e.previousElementSibling;
@@ -2116,16 +2117,14 @@
             }
         }
         if (e.parentNode.id === "main") {
-            var otherMessage;
+            var otherMessage = '';
             var fontSize;
             var extraClass;
-            var show = true;
 
             if (hasClass(e, "type-decl")) {
                 fontSize = "20px";
                 otherMessage = ' Show declaration';
-                show = getCurrentValue('rustdoc-item-declarations') === "false";
-                if (!show) {
+                if (hideItemDeclarations === false) {
                     extraClass = 'collapsed';
                 }
             } else if (hasClass(e, "non-exhaustive")) {
@@ -2142,8 +2141,12 @@
                 extraClass = "marg-left";
             }
 
-            e.parentNode.insertBefore(createToggle(otherMessage, fontSize, extraClass, show), e);
-            if (otherMessage && show) {
+            e.parentNode.insertBefore(createToggle(otherMessage,
+                                                   fontSize,
+                                                   extraClass,
+                                                   hideItemDeclarations),
+                                      e);
+            if (otherMessage.length > 0 && hideItemDeclarations === true) {
                 collapseDocs(e.previousSibling.childNodes[0], "toggle");
             }
         }
@@ -2186,13 +2189,33 @@
         });
     }
 
+    // To avoid checking on "rustdoc-item-attributes" value on every loop...
+    var itemAttributesFunc = function() {};
+    if (getCurrentValue("rustdoc-item-attributes") !== "false") {
+        itemAttributesFunc = function(x) {
+            collapseDocs(x.previousSibling.childNodes[0], "toggle");
+        };
+    }
     onEach(document.getElementById('main').getElementsByClassName('attributes'), function(i_e) {
         i_e.parentNode.insertBefore(createToggleWrapper(toggle.cloneNode(true)), i_e);
-        if (getCurrentValue("rustdoc-item-attributes") !== "false") {
-            collapseDocs(i_e.previousSibling.childNodes[0], "toggle");
-        }
+        itemAttributesFunc(i_e);
     });
 
+    // To avoid checking on "rustdoc-line-numbers" value on every loop...
+    var lineNumbersFunc = function() {};
+    if (getCurrentValue("rustdoc-line-numbers") === "true") {
+        lineNumbersFunc = function(x) {
+            var count = x.textContent.split('\n').length;
+            var elems = [];
+            for (var i = 0; i < count; ++i) {
+                elems.push(i + 1);
+            }
+            var node = document.createElement('pre');
+            addClass(node, 'line-number');
+            node.innerHTML = elems.join('\n');
+            x.parentNode.insertBefore(node, x);
+        };
+    }
     onEach(document.getElementsByClassName('rust-example-rendered'), function(e) {
         if (hasClass(e, 'compile_fail')) {
             e.addEventListener("mouseover", function(event) {
@@ -2209,6 +2232,7 @@
                 e.previousElementSibling.childNodes[0].style.color = '';
             });
         }
+        lineNumbersFunc(e);
     });
 
     function showModal(content) {

src/librustdoc/html/static/rustdoc.css

@@ -283,6 +283,24 @@ nav.sub {
 	padding-left: 0;
 }
 
+.example-wrap {
+	display: inline-flex;
+	width: 100%;
+}
+
+.example-wrap > pre.line-number {
+	overflow: initial;
+	border: 1px solid;
+	border-top-left-radius: 5px;
+	border-bottom-left-radius: 5px;
+	padding: 13px 8px;
+	text-align: right;
+}
+
+.example-wrap > pre.rust {
+	width: 100%;
+}
+
 #search {
 	margin-left: 230px;
 	position: relative;

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

@@ -233,6 +233,10 @@ pre.rust .question-mark {
 	color: #ff9011;
 }
 
+.example-wrap > pre.line-number {
+	border-color: #4a4949;
+}
+
 a.test-arrow {
 	background-color: rgba(78, 139, 202, 0.2);
 }

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

@@ -227,6 +227,10 @@ pre.rust .question-mark {
 	color: #ff9011;
 }
 
+.example-wrap > pre.line-number {
+	border-color: #c7c7c7;
+}
+
 a.test-arrow {
 	background-color: rgba(78, 139, 202, 0.2);
 }