rustdoc: use a newline instead of <br> to format code headers

Since these elements now use `white-space: pre-wrap` since
784665d, it's fine to use newlines
for formatting, which is smaller and a bit less complicated.

Author: notriddle

src/librustdoc/html/format.rs

@@ -289,7 +289,7 @@ pub(crate) fn print_where_clause<'a, 'tcx: 'a>(
                 if f.alternate() {
                     f.write_str(" ")?;
                 } else {
-                    f.write_str("<br>")?;
+                    f.write_str("\n")?;
                 }
 
                 match pred {
@@ -352,24 +352,24 @@ pub(crate) fn print_where_clause<'a, 'tcx: 'a>(
             }
         } else {
             let mut br_with_padding = String::with_capacity(6 * indent + 28);
-            br_with_padding.push_str("<br>");
+            br_with_padding.push_str("\n");
 
             let padding_amout =
                 if ending == Ending::Newline { indent + 4 } else { indent + "fn where ".len() };
 
             for _ in 0..padding_amout {
                 br_with_padding.push_str(" ");
             }
-            let where_preds = where_preds.to_string().replace("<br>", &br_with_padding);
+            let where_preds = where_preds.to_string().replace("\n", &br_with_padding);
 
             if ending == Ending::Newline {
                 let mut clause = " ".repeat(indent.saturating_sub(1));
                 write!(clause, "<span class=\"where fmt-newline\">where{where_preds},</span>")?;
                 clause
             } else {
-                // insert a <br> tag after a single space but before multiple spaces at the start
+                // insert a newline after a single space but before multiple spaces at the start
                 if indent == 0 {
-                    format!("<br><span class=\"where\">where{where_preds}</span>")
+                    format!("\n<span class=\"where\">where{where_preds}</span>")
                 } else {
                     // put the first one on the same line as the 'where' keyword
                     let where_preds = where_preds.replacen(&br_with_padding, " ", 1);
@@ -1315,7 +1315,8 @@ impl clean::FnDecl {
 
     /// * `header_len`: The length of the function header and name. In other words, the number of
     ///   characters in the function declaration up to but not including the parentheses.
-    ///   <br>Used to determine line-wrapping.
+    ///   This is expected to go into a `<pre>`/`code-header` block, so indentation and newlines
+    ///   are preserved.
     /// * `indent`: The number of spaces to indent each successive line with, if line-wrapping is
     ///   necessary.
     pub(crate) fn full_print<'a, 'tcx: 'a>(
@@ -1363,7 +1364,7 @@ impl clean::FnDecl {
                 }
             } else {
                 if i > 0 {
-                    args.push_str("<br>");
+                    args.push_str("\n");
                 }
                 if input.is_const {
                     args.push_str("const ");
@@ -1389,7 +1390,7 @@ impl clean::FnDecl {
         let mut args = args.into_inner();
 
         if self.c_variadic {
-            args.push_str(",<br> ...");
+            args.push_str(",\n ...");
             args_plain.push_str(", ...");
         }
 
@@ -1399,24 +1400,20 @@ impl clean::FnDecl {
 
         let declaration_len = header_len + args_plain.len() + arrow_plain.len();
         let output = if declaration_len > 80 {
-            let full_pad = format!("<br>{}", " ".repeat(indent + 4));
-            let close_pad = format!("<br>{}", " ".repeat(indent));
+            let full_pad = format!("\n{}", " ".repeat(indent + 4));
+            let close_pad = format!("\n{}", " ".repeat(indent));
             format!(
                 "({pad}{args}{close}){arrow}",
                 pad = if self.inputs.values.is_empty() { "" } else { &full_pad },
-                args = args.replace("<br>", &full_pad),
+                args = args.replace("\n", &full_pad),
                 close = close_pad,
                 arrow = arrow
             )
         } else {
-            format!("({args}){arrow}", args = args.replace("<br>", " "), arrow = arrow)
+            format!("({args}){arrow}", args = args.replace("\n", " "), arrow = arrow)
         };
 
-        if f.alternate() {
-            write!(f, "{}", output.replace("<br>", "\n"))
-        } else {
-            write!(f, "{}", output)
-        }
+        write!(f, "{}", output)
     }
 }
 

tests/rustdoc/async-fn.rs

@@ -77,7 +77,7 @@ struct AsyncFdReadyGuard<'a, T> { x: &'a T }
 
 impl Foo {
     // @has async_fn/struct.Foo.html
-    // @has - '//*[@class="method"]' 'pub async fn complicated_lifetimes( &self, context: &impl Bar) -> impl Iterator<Item = &usize>'
+    // @has - '//*[@class="method"]' 'pub async fn complicated_lifetimes( &self, context: &impl Bar ) -> impl Iterator<Item = &usize>'
     pub async fn complicated_lifetimes(&self, context: &impl Bar) -> impl Iterator<Item = &usize> {}
     // taken from `tokio` as an example of a method that was particularly bad before
     // @has - '//*[@class="method"]' "pub async fn readable<T>(&self) -> Result<AsyncFdReadyGuard<'_, T>, ()>"

tests/rustdoc/const-generics/const-generics-docs.rs

@@ -31,7 +31,7 @@ impl Trait<{1 + 2}> for u8 {}
 impl<const N: usize> Trait<N> for [u8; N] {}
 
 // @has foo/struct.Foo.html '//pre[@class="rust item-decl"]' \
-//      'pub struct Foo<const N: usize>where u8: Trait<N>'
+//      'pub struct Foo<const N: usize> where u8: Trait<N>'
 pub struct Foo<const N: usize> where u8: Trait<N>;
 // @has foo/struct.Bar.html '//pre[@class="rust item-decl"]' 'pub struct Bar<T, const N: usize>(_)'
 pub struct Bar<T, const N: usize>([T; N]);

tests/rustdoc/decl-trailing-whitespace.declaration.html

@@ -1,9 +1,23 @@
 <code>pub trait Write {
     // Required methods
-    fn <a href="#tymethod.poll_write" class="fn">poll_write</a>(<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;self: <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;,<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;cx: &amp;mut <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;,<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;buf: &amp;mut [<a class="primitive" href="{{channel}}/std/primitive.usize.html">usize</a>]<br />&#160;&#160;&#160;&#160;) -&gt; <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="enum" href="{{channel}}/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;<a class="primitive" href="{{channel}}/std/primitive.usize.html">usize</a>, <a class="struct" href="struct.Error.html" title="struct foo::Error">Error</a>&gt;&gt;;
-<span class="item-spacer" />    fn <a href="#tymethod.poll_flush" class="fn">poll_flush</a>(<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;self: <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;,<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;cx: &amp;mut <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;<br />&#160;&#160;&#160;&#160;) -&gt; <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="enum" href="{{channel}}/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;<a class="primitive" href="{{channel}}/std/primitive.unit.html">()</a>, <a class="struct" href="struct.Error.html" title="struct foo::Error">Error</a>&gt;&gt;;
-<span class="item-spacer" />    fn <a href="#tymethod.poll_close" class="fn">poll_close</a>(<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;self: <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;,<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;cx: &amp;mut <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;<br />&#160;&#160;&#160;&#160;) -&gt; <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="enum" href="{{channel}}/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;<a class="primitive" href="{{channel}}/std/primitive.unit.html">()</a>, <a class="struct" href="struct.Error.html" title="struct foo::Error">Error</a>&gt;&gt;;
+    fn <a href="#tymethod.poll_write" class="fn">poll_write</a>(
+        self: <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;,
+        cx: &amp;mut <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;,
+        buf: &amp;mut [<a class="primitive" href="{{channel}}/std/primitive.usize.html">usize</a>]
+    ) -&gt; <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="enum" href="{{channel}}/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;<a class="primitive" href="{{channel}}/std/primitive.usize.html">usize</a>, <a class="struct" href="struct.Error.html" title="struct foo::Error">Error</a>&gt;&gt;;
+<span class="item-spacer" />    fn <a href="#tymethod.poll_flush" class="fn">poll_flush</a>(
+        self: <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;,
+        cx: &amp;mut <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;
+    ) -&gt; <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="enum" href="{{channel}}/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;<a class="primitive" href="{{channel}}/std/primitive.unit.html">()</a>, <a class="struct" href="struct.Error.html" title="struct foo::Error">Error</a>&gt;&gt;;
+<span class="item-spacer" />    fn <a href="#tymethod.poll_close" class="fn">poll_close</a>(
+        self: <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;,
+        cx: &amp;mut <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;
+    ) -&gt; <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="enum" href="{{channel}}/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;<a class="primitive" href="{{channel}}/std/primitive.unit.html">()</a>, <a class="struct" href="struct.Error.html" title="struct foo::Error">Error</a>&gt;&gt;;
 
     // Provided method
-    fn <a href="#method.poll_write_vectored" class="fn">poll_write_vectored</a>(<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;self: <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;,<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;cx: &amp;mut <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;,<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;bufs: &amp;[<a class="primitive" href="{{channel}}/std/primitive.usize.html">usize</a>]<br />&#160;&#160;&#160;&#160;) -&gt; <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="enum" href="{{channel}}/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;<a class="primitive" href="{{channel}}/std/primitive.usize.html">usize</a>, <a class="struct" href="struct.Error.html" title="struct foo::Error">Error</a>&gt;&gt; { ... }
-}</code>
+    fn <a href="#method.poll_write_vectored" class="fn">poll_write_vectored</a>(
+        self: <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;,
+        cx: &amp;mut <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>&gt;,
+        bufs: &amp;[<a class="primitive" href="{{channel}}/std/primitive.usize.html">usize</a>]
+    ) -&gt; <a class="enum" href="{{channel}}/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="enum" href="{{channel}}/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;<a class="primitive" href="{{channel}}/std/primitive.usize.html">usize</a>, <a class="struct" href="struct.Error.html" title="struct foo::Error">Error</a>&gt;&gt; { ... }
+}</code>

tests/rustdoc/generic-associated-types/gats.rs

@@ -2,7 +2,7 @@
 
 // @has foo/trait.LendingIterator.html
 pub trait LendingIterator {
-    // @has - '//*[@id="associatedtype.Item"]//h4[@class="code-header"]' "type Item<'a>where Self: 'a"
+    // @has - '//*[@id="associatedtype.Item"]//h4[@class="code-header"]' "type Item<'a> where Self: 'a"
     type Item<'a> where Self: 'a;
 
     // @has - '//*[@id="tymethod.next"]//h4[@class="code-header"]' \
@@ -23,7 +23,7 @@ impl LendingIterator for () {
 pub struct Infinite<T>(T);
 
 // @has foo/trait.LendingIterator.html
-// @has - '//*[@id="associatedtype.Item-2"]//h4[@class="code-header"]' "type Item<'a>where Self: 'a = &'a T"
+// @has - '//*[@id="associatedtype.Item-2"]//h4[@class="code-header"]' "type Item<'a> where Self: 'a = &'a T"
 impl<T> LendingIterator for Infinite<T> {
     type Item<'a> where Self: 'a = &'a T;
 

tests/rustdoc/inline_cross/impl_trait.rs

@@ -11,7 +11,7 @@ pub use impl_trait_aux::func;
 // @has impl_trait/fn.func2.html
 // @has - '//pre[@class="rust item-decl"]' "func2<T>("
 // @has - '//pre[@class="rust item-decl"]' "_x: impl Deref<Target = Option<T>> + Iterator<Item = T>,"
-// @has - '//pre[@class="rust item-decl"]' "_y: impl Iterator<Item = u8>)"
+// @has - '//pre[@class="rust item-decl"]' "_y: impl Iterator<Item = u8> )"
 // @!has - '//pre[@class="rust item-decl"]' 'where'
 pub use impl_trait_aux::func2;
 

tests/rustdoc/issue-34928.rs

@@ -2,5 +2,5 @@
 
 pub trait Bar {}
 
-// @has foo/struct.Foo.html '//pre' 'pub struct Foo<T>(pub T)where T: Bar;'
+// @has foo/struct.Foo.html '//pre' 'pub struct Foo<T>(pub T) where T: Bar;'
 pub struct Foo<T>(pub T) where T: Bar;

tests/rustdoc/reexports-priv.rs

@@ -98,7 +98,7 @@ pub mod outer {
         pub use reexports::foo;
         // @has 'foo/outer/inner/fn.foo_crate.html' '//pre[@class="rust item-decl"]' 'pub(crate) fn foo_crate()'
         pub(crate) use reexports::foo_crate;
-        // @has 'foo/outer/inner/fn.foo_super.html' '//pre[@class="rust item-decl"]' 'pub(in outer) fn foo_super()'
+        // @has 'foo/outer/inner/fn.foo_super.html' '//pre[@class="rust item-decl"]' 'pub(in outer) fn foo_super( )'
         pub(super) use::reexports::foo_super;
         // @!has 'foo/outer/inner/fn.foo_self.html'
         pub(self) use reexports::foo_self;

tests/rustdoc/where.SWhere_Simd_item-decl.html

@@ -1 +1,3 @@
-<pre class="rust item-decl"><code>pub struct Simd&lt;T&gt;(_)<br /><span class="where">where<br />&#160;&#160;&#160;&#160;T: <a class="trait" href="trait.MyTrait.html" title="trait foo::MyTrait">MyTrait</a></span>;</code></pre>
+<pre class="rust item-decl"><code>pub struct Simd&lt;T&gt;(_)
+<span class="where">where
+         T: <a class="trait" href="trait.MyTrait.html" title="trait foo::MyTrait">MyTrait</a></span>;</code></pre>

tests/rustdoc/where.SWhere_TraitWhere_item-decl.html

@@ -1,8 +1,13 @@
 <pre class="rust item-decl"><code>pub trait TraitWhere {
-    type <a href="#associatedtype.Item" class="associatedtype">Item</a>&lt;'a&gt;<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;<span class="where">where Self: 'a</span>;
+    type <a href="#associatedtype.Item" class="associatedtype">Item</a>&lt;'a&gt;
+       <span class="where">where Self: 'a</span>;
 
     // Provided methods
-    fn <a href="#method.func" class="fn">func</a>(self)<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;<span class="where">where Self: <a class="trait" href="{{channel}}/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a></span> { ... }
-<span class="item-spacer" />    fn <a href="#method.lines" class="fn">lines</a>(self) -&gt; <a class="struct" href="{{channel}}/std/io/struct.Lines.html" title="struct std::io::Lines">Lines</a>&lt;Self&gt;<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;<span class="where">where Self: <a class="trait" href="{{channel}}/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a></span> { ... }
-<span class="item-spacer" />    fn <a href="#method.merge" class="fn">merge</a>&lt;T&gt;(self, a: T)<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;<span class="where">where Self: <a class="trait" href="{{channel}}/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,<br />&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;T: <a class="trait" href="{{channel}}/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a></span> { ... }
+    fn <a href="#method.func" class="fn">func</a>(self)
+       <span class="where">where Self: <a class="trait" href="{{channel}}/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a></span> { ... }
+<span class="item-spacer" />    fn <a href="#method.lines" class="fn">lines</a>(self) -&gt; <a class="struct" href="{{channel}}/std/io/struct.Lines.html" title="struct std::io::Lines">Lines</a>&lt;Self&gt;
+       <span class="where">where Self: <a class="trait" href="{{channel}}/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a></span> { ... }
+<span class="item-spacer" />    fn <a href="#method.merge" class="fn">merge</a>&lt;T&gt;(self, a: T)
+       <span class="where">where Self: <a class="trait" href="{{channel}}/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,
+             T: <a class="trait" href="{{channel}}/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a></span> { ... }
 }</code></pre>