rustdoc: make Method/WhereClause wrappers use usize for indents

Author: QuietMisdreavus

src/librustdoc/html/format.rs

@@ -42,15 +42,15 @@ pub struct UnsafetySpace(pub hir::Unsafety);
 #[derive(Copy, Clone)]
 pub struct ConstnessSpace(pub hir::Constness);
 /// Wrapper struct for properly emitting a method declaration.
-pub struct Method<'a>(pub &'a clean::FnDecl, pub &'a str);
+pub struct Method<'a>(pub &'a clean::FnDecl, pub usize);
 /// Similar to VisSpace, but used for mutability
 #[derive(Copy, Clone)]
 pub struct MutableSpace(pub clean::Mutability);
 /// Similar to VisSpace, but used for mutability
 #[derive(Copy, Clone)]
 pub struct RawMutableSpace(pub clean::Mutability);
 /// Wrapper struct for emitting a where clause from Generics.
-pub struct WhereClause<'a>(pub &'a clean::Generics, pub String);
+pub struct WhereClause<'a>(pub &'a clean::Generics, pub usize);
 /// Wrapper struct for emitting type parameter bounds.
 pub struct TyParamBounds<'a>(pub &'a [clean::TyParamBound]);
 /// Wrapper struct for emitting a comma-separated list of items
@@ -157,7 +157,7 @@ impl fmt::Display for clean::Generics {
 
 impl<'a> fmt::Display for WhereClause<'a> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        let &WhereClause(gens, ref pad) = self;
+        let &WhereClause(gens, pad) = self;
         if gens.where_predicates.is_empty() {
             return Ok(());
         }
@@ -207,14 +207,14 @@ impl<'a> fmt::Display for WhereClause<'a> {
         if !f.alternate() {
             clause.push_str("</span>");
             let plain = format!("{:#}", self);
-            if plain.len() + pad.len() > 80 {
+            if plain.len() > 80 {
                 //break it onto its own line regardless, but make sure method impls and trait
                 //blocks keep their fixed padding (2 and 9, respectively)
-                let padding = if pad.len() > 10 {
+                let padding = if pad > 10 {
                     clause = clause.replace("class='where'", "class='where fmt-newline'");
                     repeat("&nbsp;").take(8).collect::<String>()
                 } else {
-                    repeat("&nbsp;").take(pad.len() + 6).collect::<String>()
+                    repeat("&nbsp;").take(pad + 6).collect::<String>()
                 };
                 clause = clause.replace("<br>", &format!("<br>{}", padding));
             } else {
@@ -773,8 +773,7 @@ fn fmt_impl(i: &clean::Impl, f: &mut fmt::Formatter, link_trait: bool) -> fmt::R
     fmt::Display::fmt(&i.for_, f)?;
     plain.push_str(&format!("{:#}", i.for_));
 
-    let pad = repeat(" ").take(plain.len() + 1).collect::<String>();
-    fmt::Display::fmt(&WhereClause(&i.generics, pad), f)?;
+    fmt::Display::fmt(&WhereClause(&i.generics, plain.len() + 1), f)?;
     Ok(())
 }
 
@@ -903,19 +902,21 @@ impl<'a> fmt::Display for Method<'a> {
 
         let mut output: String;
         let plain: String;
+        let pad = repeat(" ").take(indent).collect::<String>();
         if arrow.is_empty() {
             output = format!("({})", args);
-            plain = format!("{}({})", indent.replace("&nbsp;", " "), args_plain);
+            plain = format!("{}({})", pad, args_plain);
         } else {
             output = format!("({args})<br>{arrow}", args = args, arrow = arrow);
-            plain = format!("{indent}({args}){arrow}",
-                            indent = indent.replace("&nbsp;", " "),
+            plain = format!("{pad}({args}){arrow}",
+                            pad = pad,
                             args = args_plain,
                             arrow = arrow_plain);
         }
 
         if plain.len() > 80 {
-            let pad = format!("<br>{}", indent);
+            let pad = repeat("&nbsp;").take(indent).collect::<String>();
+            let pad = format!("<br>{}", pad);
             output = output.replace("<br>", &pad);
         } else {
             output = output.replace("<br>", "");

src/librustdoc/html/render.rs

@@ -1967,14 +1967,13 @@ fn item_function(w: &mut fmt::Formatter, cx: &Context, it: &clean::Item,
         UnstableFeatures::Allow => f.constness,
         _ => hir::Constness::NotConst
     };
-    let prefix = format!("{}{}{}{:#}fn {}{:#}",
+    let indent = format!("{}{}{}{:#}fn {}{:#}",
                          VisSpace(&it.visibility),
                          ConstnessSpace(vis_constness),
                          UnsafetySpace(f.unsafety),
                          AbiSpace(f.abi),
                          it.name.as_ref().unwrap(),
-                         f.generics);
-    let indent = repeat("&nbsp;").take(prefix.len()).collect::<String>();
+                         f.generics).len();
     write!(w, "<pre class='rust fn'>{vis}{constness}{unsafety}{abi}fn \
                {name}{generics}{decl}{where_clause}</pre>",
            vis = VisSpace(&it.visibility),
@@ -1983,8 +1982,8 @@ fn item_function(w: &mut fmt::Formatter, cx: &Context, it: &clean::Item,
            abi = AbiSpace(f.abi),
            name = it.name.as_ref().unwrap(),
            generics = f.generics,
-           where_clause = WhereClause(&f.generics, "  ".to_string()),
-           decl = Method(&f.decl, &indent))?;
+           where_clause = WhereClause(&f.generics, 2),
+           decl = Method(&f.decl, indent))?;
     document(w, cx, it)
 }
 
@@ -2009,17 +2008,15 @@ fn item_trait(w: &mut fmt::Formatter, cx: &Context, it: &clean::Item,
         }
     }
 
-    // Where clauses in traits are indented nine spaces, per rustdoc.css
-    let indent = "         ".to_string();
-
     // Output the trait definition
     write!(w, "<pre class='rust trait'>{}{}trait {}{}{}{} ",
            VisSpace(&it.visibility),
            UnsafetySpace(t.unsafety),
            it.name.as_ref().unwrap(),
            t.generics,
            bounds,
-           WhereClause(&t.generics, indent))?;
+           // Where clauses in traits are indented nine spaces, per rustdoc.css
+           WhereClause(&t.generics, 9))?;
 
     let types = t.items.iter().filter(|m| m.is_associated_type()).collect::<Vec<_>>();
     let consts = t.items.iter().filter(|m| m.is_associated_const()).collect::<Vec<_>>();
@@ -2272,16 +2269,15 @@ fn render_assoc_item(w: &mut fmt::Formatter,
                              AbiSpace(abi),
                              name,
                              *g);
-        let mut indent = repeat("&nbsp;").take(prefix.len()).collect::<String>();
+        let mut indent = prefix.len();
         let where_indent = if parent == ItemType::Trait {
-            indent += "&nbsp;&nbsp;&nbsp;&nbsp;";
-            "        ".to_string()
+            indent += 4;
+            8
         } else if parent == ItemType::Impl {
-            "  ".to_string()
+            2
         } else {
-            let prefix = prefix + &format!("{:#}", Method(d, &indent));
-            let prefix = prefix.lines().last().unwrap();
-            repeat(" ").take(prefix.len() + 1).collect::<String>()
+            let prefix = prefix + &format!("{:#}", Method(d, indent));
+            prefix.lines().last().unwrap().len() + 1
         };
         write!(w, "{}{}{}fn <a href='{href}' class='fnname'>{name}</a>\
                    {generics}{decl}{where_clause}",
@@ -2291,7 +2287,7 @@ fn render_assoc_item(w: &mut fmt::Formatter,
                href = href,
                name = name,
                generics = *g,
-               decl = Method(d, &indent),
+               decl = Method(d, indent),
                where_clause = WhereClause(g, where_indent))
     }
     match item.inner {
@@ -2402,7 +2398,7 @@ fn item_enum(w: &mut fmt::Formatter, cx: &Context, it: &clean::Item,
     let padding = format!("{}enum {}{:#} ",
                           VisSpace(&it.visibility),
                           it.name.as_ref().unwrap(),
-                          e.generics);
+                          e.generics).len();
     write!(w, "{}enum {}{}{}",
            VisSpace(&it.visibility),
            it.name.as_ref().unwrap(),
@@ -2558,8 +2554,7 @@ fn render_struct(w: &mut fmt::Formatter, it: &clean::Item,
     match ty {
         doctree::Plain => {
             if let Some(g) = g {
-                let pad = repeat(" ").take(plain.len() + 1).collect::<String>();
-                write!(w, "{}", WhereClause(g, pad))?
+                write!(w, "{}", WhereClause(g, plain.len() + 1))?
             }
             let mut has_visible_fields = false;
             write!(w, " {{")?;
@@ -2609,16 +2604,14 @@ fn render_struct(w: &mut fmt::Formatter, it: &clean::Item,
             write!(w, ")")?;
             plain.push_str(")");
             if let Some(g) = g {
-                let pad = repeat(" ").take(plain.len() + 1).collect::<String>();
-                write!(w, "{}", WhereClause(g, pad))?
+                write!(w, "{}", WhereClause(g, plain.len() + 1))?
             }
             write!(w, ";")?;
         }
         doctree::Unit => {
             // Needed for PhantomData.
             if let Some(g) = g {
-                let pad = repeat(" ").take(plain.len() + 1).collect::<String>();
-                write!(w, "{}", WhereClause(g, pad))?
+                write!(w, "{}", WhereClause(g, plain.len() + 1))?
             }
             write!(w, ";")?;
         }
@@ -2643,8 +2636,7 @@ fn render_union(w: &mut fmt::Formatter, it: &clean::Item,
     if let Some(g) = g {
         write!(w, "{}", g)?;
         plain.push_str(&format!("{:#}", g));
-        let pad = repeat(" ").take(plain.len() + 1).collect::<String>();
-        write!(w, "{}", WhereClause(g, pad))?;
+        write!(w, "{}", WhereClause(g, plain.len() + 1))?;
     }
 
     write!(w, " {{\n{}", tab)?;
@@ -2945,8 +2937,7 @@ fn render_impl(w: &mut fmt::Formatter, cx: &Context, i: &Impl, link: AssocItemLi
 
 fn item_typedef(w: &mut fmt::Formatter, cx: &Context, it: &clean::Item,
                 t: &clean::Typedef) -> fmt::Result {
-    let indent = format!("type {}{:#} ", it.name.as_ref().unwrap(), t.generics);
-    let indent = repeat(" ").take(indent.len()).collect::<String>();
+    let indent = format!("type {}{:#} ", it.name.as_ref().unwrap(), t.generics).len();
     write!(w, "<pre class='rust typedef'>type {}{}{where_clause} = {type_};</pre>",
            it.name.as_ref().unwrap(),
            t.generics,