1 //! HTML formatting module
3 //! This module contains a large number of `fmt::Display` implementations for
4 //! various types in `rustdoc::clean`. These implementations all currently
5 //! assume that HTML output is desired, although it may be possible to redesign
6 //! them in the future to instead emit any format desired.
12 use rustc_attr::{ConstStability, StabilityLevel};
13 use rustc_data_structures::captures::Captures;
14 use rustc_data_structures::fx::FxHashSet;
16 use rustc_hir::def::DefKind;
17 use rustc_hir::def_id::DefId;
19 use rustc_middle::ty::DefIdTree;
20 use rustc_middle::ty::TyCtxt;
21 use rustc_span::def_id::CRATE_DEF_INDEX;
22 use rustc_target::spec::abi::Abi;
24 use crate::clean::{self, utils::find_nearest_parent_module, ExternalCrate, ItemId, PrimitiveType};
25 use crate::formats::item_type::ItemType;
26 use crate::html::escape::Escape;
27 use crate::html::render::cache::ExternalLocation;
28 use crate::html::render::Context;
31 fn print(self, buffer: &mut Buffer);
36 F: FnOnce(&mut Buffer),
38 fn print(self, buffer: &mut Buffer) {
43 impl Print for String {
44 fn print(self, buffer: &mut Buffer) {
45 buffer.write_str(&self);
49 impl Print for &'_ str {
50 fn print(self, buffer: &mut Buffer) {
51 buffer.write_str(self);
55 #[derive(Debug, Clone)]
62 crate fn empty_from(v: &Buffer) -> Buffer {
63 Buffer { for_html: v.for_html, buffer: String::new() }
66 crate fn html() -> Buffer {
67 Buffer { for_html: true, buffer: String::new() }
70 crate fn new() -> Buffer {
71 Buffer { for_html: false, buffer: String::new() }
74 crate fn is_empty(&self) -> bool {
75 self.buffer.is_empty()
78 crate fn into_inner(self) -> String {
82 crate fn insert_str(&mut self, idx: usize, s: &str) {
83 self.buffer.insert_str(idx, s);
86 crate fn push_str(&mut self, s: &str) {
87 self.buffer.push_str(s);
90 crate fn push_buffer(&mut self, other: Buffer) {
91 self.buffer.push_str(&other.buffer);
94 // Intended for consumption by write! and writeln! (std::fmt) but without
95 // the fmt::Result return type imposed by fmt::Write (and avoiding the trait
97 crate fn write_str(&mut self, s: &str) {
98 self.buffer.push_str(s);
101 // Intended for consumption by write! and writeln! (std::fmt) but without
102 // the fmt::Result return type imposed by fmt::Write (and avoiding the trait
104 crate fn write_fmt(&mut self, v: fmt::Arguments<'_>) {
106 self.buffer.write_fmt(v).unwrap();
109 crate fn to_display<T: Print>(mut self, t: T) -> String {
114 crate fn is_for_html(&self) -> bool {
118 crate fn reserve(&mut self, additional: usize) {
119 self.buffer.reserve(additional)
123 fn comma_sep<T: fmt::Display>(items: impl Iterator<Item = T>) -> impl fmt::Display {
124 display_fn(move |f| {
125 for (i, item) in items.enumerate() {
129 fmt::Display::fmt(&item, f)?;
135 crate fn print_generic_bounds<'a, 'tcx: 'a>(
136 bounds: &'a [clean::GenericBound],
137 cx: &'a Context<'tcx>,
138 ) -> impl fmt::Display + 'a + Captures<'tcx> {
139 display_fn(move |f| {
140 let mut bounds_dup = FxHashSet::default();
143 bounds.iter().filter(|b| bounds_dup.insert(b.print(cx).to_string())).enumerate()
148 fmt::Display::fmt(&bound.print(cx), f)?;
154 impl clean::GenericParamDef {
155 crate fn print<'a, 'tcx: 'a>(
157 cx: &'a Context<'tcx>,
158 ) -> impl fmt::Display + 'a + Captures<'tcx> {
159 display_fn(move |f| match &self.kind {
160 clean::GenericParamDefKind::Lifetime { outlives } => {
161 write!(f, "{}", self.name)?;
163 if !outlives.is_empty() {
165 for (i, lt) in outlives.iter().enumerate() {
169 write!(f, "{}", lt.print())?;
175 clean::GenericParamDefKind::Type { bounds, default, .. } => {
176 f.write_str(&*self.name.as_str())?;
178 if !bounds.is_empty() {
180 write!(f, ": {:#}", print_generic_bounds(bounds, cx))?;
182 write!(f, ": {}", print_generic_bounds(bounds, cx))?;
186 if let Some(ref ty) = default {
188 write!(f, " = {:#}", ty.print(cx))?;
190 write!(f, " = {}", ty.print(cx))?;
196 clean::GenericParamDefKind::Const { ty, default, .. } => {
198 write!(f, "const {}: {:#}", self.name, ty.print(cx))?;
200 write!(f, "const {}: {}", self.name, ty.print(cx))?;
203 if let Some(default) = default {
205 write!(f, " = {:#}", default)?;
207 write!(f, " = {}", default)?;
217 impl clean::Generics {
218 crate fn print<'a, 'tcx: 'a>(
220 cx: &'a Context<'tcx>,
221 ) -> impl fmt::Display + 'a + Captures<'tcx> {
222 display_fn(move |f| {
224 self.params.iter().filter(|p| !p.is_synthetic_type_param()).collect::<Vec<_>>();
225 if real_params.is_empty() {
229 write!(f, "<{:#}>", comma_sep(real_params.iter().map(|g| g.print(cx))))
231 write!(f, "<{}>", comma_sep(real_params.iter().map(|g| g.print(cx))))
237 /// * The Generics from which to emit a where-clause.
238 /// * The number of spaces to indent each line with.
239 /// * Whether the where-clause needs to add a comma and newline after the last bound.
240 crate fn print_where_clause<'a, 'tcx: 'a>(
241 gens: &'a clean::Generics,
242 cx: &'a Context<'tcx>,
245 ) -> impl fmt::Display + 'a + Captures<'tcx> {
246 display_fn(move |f| {
247 if gens.where_predicates.is_empty() {
250 let mut clause = String::new();
252 clause.push_str(" where");
255 clause.push_str(" <span class=\"where fmt-newline\">where");
257 clause.push_str(" <span class=\"where\">where");
260 for (i, pred) in gens.where_predicates.iter().enumerate() {
264 clause.push_str("<br>");
268 clean::WherePredicate::BoundPredicate { ty, bounds, bound_params } => {
270 let for_prefix = match bound_params.len() {
272 _ if f.alternate() => {
275 comma_sep(bound_params.iter().map(|lt| lt.print()))
280 comma_sep(bound_params.iter().map(|lt| lt.print()))
285 clause.push_str(&format!(
289 print_generic_bounds(bounds, cx)
292 clause.push_str(&format!(
296 print_generic_bounds(bounds, cx)
300 clean::WherePredicate::RegionPredicate { lifetime, bounds } => {
301 clause.push_str(&format!(
306 .map(|b| b.print(cx).to_string())
311 clean::WherePredicate::EqPredicate { lhs, rhs } => {
313 clause.push_str(&format!("{:#} == {:#}", lhs.print(cx), rhs.print(cx),));
315 clause.push_str(&format!("{} == {}", lhs.print(cx), rhs.print(cx),));
320 if i < gens.where_predicates.len() - 1 || end_newline {
326 // add a space so stripping <br> tags and breaking spaces still renders properly
330 clause.push_str(" ");
335 clause.push_str("</span>");
336 let padding = " ".repeat(indent + 4);
337 clause = clause.replace("<br>", &format!("<br>{}", padding));
338 clause.insert_str(0, &" ".repeat(indent.saturating_sub(1)));
340 clause.insert_str(0, "<br>");
343 write!(f, "{}", clause)
347 impl clean::Lifetime {
348 crate fn print(&self) -> impl fmt::Display + '_ {
353 impl clean::Constant {
354 crate fn print(&self, tcx: TyCtxt<'_>) -> impl fmt::Display + '_ {
355 let expr = self.expr(tcx);
358 if f.alternate() { f.write_str(&expr) } else { write!(f, "{}", Escape(&expr)) }
364 impl clean::PolyTrait {
365 fn print<'a, 'tcx: 'a>(
367 cx: &'a Context<'tcx>,
368 ) -> impl fmt::Display + 'a + Captures<'tcx> {
369 display_fn(move |f| {
370 if !self.generic_params.is_empty() {
375 comma_sep(self.generic_params.iter().map(|g| g.print(cx)))
381 comma_sep(self.generic_params.iter().map(|g| g.print(cx)))
386 write!(f, "{:#}", self.trait_.print(cx))
388 write!(f, "{}", self.trait_.print(cx))
394 impl clean::GenericBound {
395 crate fn print<'a, 'tcx: 'a>(
397 cx: &'a Context<'tcx>,
398 ) -> impl fmt::Display + 'a + Captures<'tcx> {
399 display_fn(move |f| match self {
400 clean::GenericBound::Outlives(lt) => write!(f, "{}", lt.print()),
401 clean::GenericBound::TraitBound(ty, modifier) => {
402 let modifier_str = match modifier {
403 hir::TraitBoundModifier::None => "",
404 hir::TraitBoundModifier::Maybe => "?",
405 hir::TraitBoundModifier::MaybeConst => "~const",
408 write!(f, "{}{:#}", modifier_str, ty.print(cx))
410 write!(f, "{}{}", modifier_str, ty.print(cx))
417 impl clean::GenericArgs {
418 fn print<'a, 'tcx: 'a>(
420 cx: &'a Context<'tcx>,
421 ) -> impl fmt::Display + 'a + Captures<'tcx> {
422 display_fn(move |f| {
424 clean::GenericArgs::AngleBracketed { args, bindings } => {
425 if !args.is_empty() || !bindings.is_empty() {
429 f.write_str("<")?;
431 let mut comma = false;
438 write!(f, "{:#}", arg.print(cx))?;
440 write!(f, "{}", arg.print(cx))?;
443 for binding in bindings {
449 write!(f, "{:#}", binding.print(cx))?;
451 write!(f, "{}", binding.print(cx))?;
457 f.write_str(">")?;
461 clean::GenericArgs::Parenthesized { inputs, output } => {
463 let mut comma = false;
470 write!(f, "{:#}", ty.print(cx))?;
472 write!(f, "{}", ty.print(cx))?;
476 if let Some(ref ty) = *output {
478 write!(f, " -> {:#}", ty.print(cx))?;
480 write!(f, " -> {}", ty.print(cx))?;
490 // Possible errors when computing href link source for a `DefId`
491 crate enum HrefError {
492 /// This item is known to rustdoc, but from a crate that does not have documentation generated.
494 /// This can only happen for non-local items.
495 DocumentationNotBuilt,
496 /// This can only happen for non-local items when `--document-private-items` is not passed.
498 // Not in external cache, href link should be in same page
502 crate fn href_with_root_path(
505 root_path: Option<&str>,
506 ) -> Result<(String, ItemType, Vec<String>), HrefError> {
508 let def_kind = tcx.def_kind(did);
509 let did = match def_kind {
510 DefKind::AssocTy | DefKind::AssocFn | DefKind::AssocConst | DefKind::Variant => {
511 // documented on their parent's page
512 tcx.parent(did).unwrap()
516 let cache = cx.cache();
517 let relative_to = &cx.current;
518 fn to_module_fqp(shortty: ItemType, fqp: &[String]) -> &[String] {
519 if shortty == ItemType::Module { fqp } else { &fqp[..fqp.len() - 1] }
523 && !cache.access_levels.is_public(did)
524 && !cache.document_private
525 && !cache.primitive_locations.values().any(|&id| id == did)
527 return Err(HrefError::Private);
530 let mut is_remote = false;
531 let (fqp, shortty, mut url_parts) = match cache.paths.get(&did) {
532 Some(&(ref fqp, shortty)) => (fqp, shortty, {
533 let module_fqp = to_module_fqp(shortty, fqp);
534 debug!(?fqp, ?shortty, ?module_fqp);
535 href_relative_parts(module_fqp, relative_to)
538 if let Some(&(ref fqp, shortty)) = cache.external_paths.get(&did) {
539 let module_fqp = to_module_fqp(shortty, fqp);
543 match cache.extern_locations[&did.krate] {
544 ExternalLocation::Remote(ref s) => {
546 let s = s.trim_end_matches('/');
548 s.extend(module_fqp[..].iter().map(String::as_str));
551 ExternalLocation::Local => href_relative_parts(module_fqp, relative_to),
552 ExternalLocation::Unknown => return Err(HrefError::DocumentationNotBuilt),
556 return Err(HrefError::NotInExternalCache);
561 if let Some(root_path) = root_path {
562 let root = root_path.trim_end_matches('/');
563 url_parts.insert(0, root);
567 let last = &fqp.last().unwrap()[..];
570 ItemType::Module => {
571 url_parts.push("index.html");
574 filename = format!("{}.{}.html", shortty.as_str(), last);
575 url_parts.push(&filename);
578 Ok((url_parts.join("/"), shortty, fqp.to_vec()))
581 crate fn href(did: DefId, cx: &Context<'_>) -> Result<(String, ItemType, Vec<String>), HrefError> {
582 href_with_root_path(did, cx, None)
585 /// Both paths should only be modules.
586 /// This is because modules get their own directories; that is, `std::vec` and `std::vec::Vec` will
587 /// both need `../iter/trait.Iterator.html` to get at the iterator trait.
588 crate fn href_relative_parts<'a>(fqp: &'a [String], relative_to_fqp: &'a [String]) -> Vec<&'a str> {
589 for (i, (f, r)) in fqp.iter().zip(relative_to_fqp.iter()).enumerate() {
590 // e.g. linking to std::iter from std::vec (`dissimilar_part_count` will be 1)
592 let dissimilar_part_count = relative_to_fqp.len() - i;
593 let fqp_module = fqp[i..fqp.len()].iter().map(String::as_str);
594 return iter::repeat("..").take(dissimilar_part_count).chain(fqp_module).collect();
597 // e.g. linking to std::sync::atomic from std::sync
598 if relative_to_fqp.len() < fqp.len() {
599 fqp[relative_to_fqp.len()..fqp.len()].iter().map(String::as_str).collect()
600 // e.g. linking to std::sync from std::sync::atomic
601 } else if fqp.len() < relative_to_fqp.len() {
602 let dissimilar_part_count = relative_to_fqp.len() - fqp.len();
603 iter::repeat("..").take(dissimilar_part_count).collect()
604 // linking to the same module
610 /// Used to render a [`clean::Path`].
611 fn resolved_path<'cx>(
612 w: &mut fmt::Formatter<'_>,
617 cx: &'cx Context<'_>,
619 let last = path.segments.last().unwrap();
622 for seg in &path.segments[..path.segments.len() - 1] {
623 write!(w, "{}::", seg.name)?;
627 write!(w, "{}{:#}", &last.name, last.args.print(cx))?;
629 let path = if use_absolute {
630 if let Ok((_, _, fqp)) = href(did, cx) {
633 fqp[..fqp.len() - 1].join("::"),
634 anchor(did, fqp.last().unwrap(), cx)
637 last.name.to_string()
640 anchor(did, &*last.name.as_str(), cx).to_string()
642 write!(w, "{}{}", path, last.args.print(cx))?;
648 f: &mut fmt::Formatter<'_>,
649 prim: clean::PrimitiveType,
654 let mut needs_termination = false;
656 match m.primitive_locations.get(&prim) {
657 Some(&def_id) if def_id.is_local() => {
658 let len = cx.current.len();
659 let len = if len == 0 { 0 } else { len - 1 };
662 "<a class=\"primitive\" href=\"{}primitive.{}.html\">",
666 needs_termination = true;
670 let loc = match m.extern_locations[&def_id.krate] {
671 ExternalLocation::Remote(ref s) => {
673 ExternalCrate { crate_num: def_id.krate }.name(cx.tcx()).as_str();
674 Some(vec![s.trim_end_matches('/'), &cname_str[..]])
676 ExternalLocation::Local => {
678 ExternalCrate { crate_num: def_id.krate }.name(cx.tcx()).as_str();
679 Some(if cx.current.first().map(|x| &x[..]) == Some(&cname_str[..]) {
680 iter::repeat("..").take(cx.current.len() - 1).collect()
682 let cname = iter::once(&cname_str[..]);
683 iter::repeat("..").take(cx.current.len()).chain(cname).collect()
686 ExternalLocation::Unknown => None,
688 if let Some(loc) = loc {
691 "<a class=\"primitive\" href=\"{}/primitive.{}.html\">",
695 needs_termination = true;
701 write!(f, "{}", name)?;
702 if needs_termination {
708 /// Helper to render type parameters
709 fn tybounds<'a, 'tcx: 'a>(
710 bounds: &'a [clean::PolyTrait],
711 lt: &'a Option<clean::Lifetime>,
712 cx: &'a Context<'tcx>,
713 ) -> impl fmt::Display + 'a + Captures<'tcx> {
714 display_fn(move |f| {
715 for (i, bound) in bounds.iter().enumerate() {
720 fmt::Display::fmt(&bound.print(cx), f)?;
723 if let Some(lt) = lt {
725 fmt::Display::fmt(<.print(), f)?;
731 crate fn anchor<'a, 'cx: 'a>(
734 cx: &'cx Context<'_>,
735 ) -> impl fmt::Display + 'a {
736 let parts = href(did, cx);
737 display_fn(move |f| {
738 if let Ok((url, short_ty, fqp)) = parts {
741 r#"<a class="{}" href="{}" title="{} {}">{}</a>"#,
749 write!(f, "{}", text)
756 f: &mut fmt::Formatter<'_>,
758 cx: &'cx Context<'_>,
760 trace!("fmt_type(t = {:?})", t);
763 clean::Generic(name) => write!(f, "{}", name),
764 clean::Type::Path { ref path } => {
765 // Paths like `T::Output` and `Self::Output` should be rendered with all segments.
766 let did = path.def_id();
767 resolved_path(f, did, path, path.is_assoc_ty(), use_absolute, cx)
769 clean::DynTrait(ref bounds, ref lt) => {
770 f.write_str("dyn ")?;
771 fmt::Display::fmt(&tybounds(bounds, lt, cx), f)
773 clean::Infer => write!(f, "_"),
774 clean::Primitive(clean::PrimitiveType::Never) => {
775 primitive_link(f, PrimitiveType::Never, "!", cx)
777 clean::Primitive(prim) => primitive_link(f, prim, &*prim.as_sym().as_str(), cx),
778 clean::BareFunction(ref decl) => {
783 decl.print_hrtb_with_space(cx),
784 decl.unsafety.print_with_space(),
785 print_abi_with_space(decl.abi),
792 decl.print_hrtb_with_space(cx),
793 decl.unsafety.print_with_space(),
794 print_abi_with_space(decl.abi)
796 primitive_link(f, PrimitiveType::Fn, "fn", cx)?;
797 write!(f, "{}", decl.decl.print(cx))
800 clean::Tuple(ref typs) => {
802 &[] => primitive_link(f, PrimitiveType::Unit, "()", cx),
804 primitive_link(f, PrimitiveType::Tuple, "(", cx)?;
805 // Carry `f.alternate()` into this display w/o branching manually.
806 fmt::Display::fmt(&one.print(cx), f)?;
807 primitive_link(f, PrimitiveType::Tuple, ",)", cx)
810 primitive_link(f, PrimitiveType::Tuple, "(", cx)?;
811 for (i, item) in many.iter().enumerate() {
815 fmt::Display::fmt(&item.print(cx), f)?;
817 primitive_link(f, PrimitiveType::Tuple, ")", cx)
821 clean::Slice(ref t) => {
822 primitive_link(f, PrimitiveType::Slice, "[", cx)?;
823 fmt::Display::fmt(&t.print(cx), f)?;
824 primitive_link(f, PrimitiveType::Slice, "]", cx)
826 clean::Array(ref t, ref n) => {
827 primitive_link(f, PrimitiveType::Array, "[", cx)?;
828 fmt::Display::fmt(&t.print(cx), f)?;
830 primitive_link(f, PrimitiveType::Array, &format!("; {}]", n), cx)
832 primitive_link(f, PrimitiveType::Array, &format!("; {}]", Escape(n)), cx)
835 clean::RawPointer(m, ref t) => {
837 hir::Mutability::Mut => "mut",
838 hir::Mutability::Not => "const",
841 if matches!(**t, clean::Generic(_)) || t.is_assoc_ty() {
842 let text = if f.alternate() {
843 format!("*{} {:#}", m, t.print(cx))
845 format!("*{} {}", m, t.print(cx))
847 primitive_link(f, clean::PrimitiveType::RawPointer, &text, cx)
849 primitive_link(f, clean::PrimitiveType::RawPointer, &format!("*{} ", m), cx)?;
850 fmt::Display::fmt(&t.print(cx), f)
853 clean::BorrowedRef { lifetime: ref l, mutability, type_: ref ty } => {
855 Some(l) => format!("{} ", l.print()),
858 let m = mutability.print_with_space();
859 let amp = if f.alternate() { "&".to_string() } else { "&".to_string() };
861 clean::Slice(ref bt) => {
862 // `BorrowedRef{ ... Slice(T) }` is `&[T]`
864 clean::Generic(_) => {
868 PrimitiveType::Slice,
869 &format!("{}{}{}[{:#}]", amp, lt, m, bt.print(cx)),
875 PrimitiveType::Slice,
876 &format!("{}{}{}[{}]", amp, lt, m, bt.print(cx)),
884 PrimitiveType::Slice,
885 &format!("{}{}{}[", amp, lt, m),
889 write!(f, "{:#}", bt.print(cx))?;
891 write!(f, "{}", bt.print(cx))?;
893 primitive_link(f, PrimitiveType::Slice, "]", cx)
897 clean::DynTrait(ref bounds, ref trait_lt)
898 if bounds.len() > 1 || trait_lt.is_some() =>
900 write!(f, "{}{}{}(", amp, lt, m)?;
901 fmt_type(ty, f, use_absolute, cx)?;
904 clean::Generic(..) => {
907 PrimitiveType::Reference,
908 &format!("{}{}{}", amp, lt, m),
911 fmt_type(ty, f, use_absolute, cx)
914 write!(f, "{}{}{}", amp, lt, m)?;
915 fmt_type(ty, f, use_absolute, cx)
919 clean::ImplTrait(ref bounds) => {
921 write!(f, "impl {:#}", print_generic_bounds(bounds, cx))
923 write!(f, "impl {}", print_generic_bounds(bounds, cx))
926 clean::QPath { ref name, ref self_type, ref trait_, ref self_def_id } => {
927 let should_show_cast = !trait_.segments.is_empty()
929 .zip(Some(trait_.def_id()))
930 .map_or(!self_type.is_self_type(), |(id, trait_)| id != trait_);
932 if should_show_cast {
933 write!(f, "<{:#} as {:#}>::", self_type.print(cx), trait_.print(cx))?
935 write!(f, "{:#}::", self_type.print(cx))?
938 if should_show_cast {
939 write!(f, "<{} as {}>::", self_type.print(cx), trait_.print(cx))?
941 write!(f, "{}::", self_type.print(cx))?
944 // It's pretty unsightly to look at `<A as B>::C` in output, and
945 // we've got hyperlinking on our side, so try to avoid longer
946 // notation as much as possible by making `C` a hyperlink to trait
947 // `B` to disambiguate.
949 // FIXME: this is still a lossy conversion and there should probably
950 // be a better way of representing this in general? Most of
951 // the ugliness comes from inlining across crates where
952 // everything comes in as a fully resolved QPath (hard to
954 match href(trait_.def_id(), cx) {
955 Ok((ref url, _, ref path)) if !f.alternate() => {
958 "<a class=\"type\" href=\"{url}#{shortty}.{name}\" \
959 title=\"type {path}::{name}\">{name}</a>",
961 shortty = ItemType::AssocType,
963 path = path.join("::")
966 _ => write!(f, "{}", name)?,
974 crate fn print<'b, 'a: 'b, 'tcx: 'a>(
976 cx: &'a Context<'tcx>,
977 ) -> impl fmt::Display + 'b + Captures<'tcx> {
978 display_fn(move |f| fmt_type(self, f, false, cx))
983 crate fn print<'b, 'a: 'b, 'tcx: 'a>(
985 cx: &'a Context<'tcx>,
986 ) -> impl fmt::Display + 'b + Captures<'tcx> {
987 display_fn(move |f| resolved_path(f, self.def_id(), self, false, false, cx))
992 crate fn print<'a, 'tcx: 'a>(
995 cx: &'a Context<'tcx>,
996 ) -> impl fmt::Display + 'a + Captures<'tcx> {
997 display_fn(move |f| {
999 write!(f, "impl{:#} ", self.generics.print(cx))?;
1001 write!(f, "impl{} ", self.generics.print(cx))?;
1004 if let Some(ref ty) = self.trait_ {
1005 match self.polarity {
1006 ty::ImplPolarity::Positive | ty::ImplPolarity::Reservation => {}
1007 ty::ImplPolarity::Negative => write!(f, "!")?,
1009 fmt::Display::fmt(&ty.print(cx), f)?;
1010 write!(f, " for ")?;
1013 if let Some(ref ty) = self.kind.as_blanket_ty() {
1014 fmt_type(ty, f, use_absolute, cx)?;
1016 fmt_type(&self.for_, f, use_absolute, cx)?;
1019 fmt::Display::fmt(&print_where_clause(&self.generics, cx, 0, true), f)?;
1025 impl clean::Arguments {
1026 crate fn print<'a, 'tcx: 'a>(
1028 cx: &'a Context<'tcx>,
1029 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1030 display_fn(move |f| {
1031 for (i, input) in self.values.iter().enumerate() {
1032 if !input.name.is_empty() {
1033 write!(f, "{}: ", input.name)?;
1036 write!(f, "{:#}", input.type_.print(cx))?;
1038 write!(f, "{}", input.type_.print(cx))?;
1040 if i + 1 < self.values.len() {
1049 impl clean::FnRetTy {
1050 crate fn print<'a, 'tcx: 'a>(
1052 cx: &'a Context<'tcx>,
1053 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1054 display_fn(move |f| match self {
1055 clean::Return(clean::Tuple(tys)) if tys.is_empty() => Ok(()),
1056 clean::Return(ty) if f.alternate() => {
1057 write!(f, " -> {:#}", ty.print(cx))
1059 clean::Return(ty) => write!(f, " -> {}", ty.print(cx)),
1060 clean::DefaultReturn => Ok(()),
1065 impl clean::BareFunctionDecl {
1066 fn print_hrtb_with_space<'a, 'tcx: 'a>(
1068 cx: &'a Context<'tcx>,
1069 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1070 display_fn(move |f| {
1071 if !self.generic_params.is_empty() {
1075 comma_sep(self.generic_params.iter().map(|g| g.print(cx)))
1084 impl clean::FnDecl {
1085 crate fn print<'b, 'a: 'b, 'tcx: 'a>(
1087 cx: &'a Context<'tcx>,
1088 ) -> impl fmt::Display + 'b + Captures<'tcx> {
1089 display_fn(move |f| {
1090 let ellipsis = if self.c_variadic { ", ..." } else { "" };
1094 "({args:#}{ellipsis}){arrow:#}",
1095 args = self.inputs.print(cx),
1096 ellipsis = ellipsis,
1097 arrow = self.output.print(cx)
1102 "({args}{ellipsis}){arrow}",
1103 args = self.inputs.print(cx),
1104 ellipsis = ellipsis,
1105 arrow = self.output.print(cx)
1111 /// * `header_len`: The length of the function header and name. In other words, the number of
1112 /// characters in the function declaration up to but not including the parentheses.
1113 /// <br>Used to determine line-wrapping.
1114 /// * `indent`: The number of spaces to indent each successive line with, if line-wrapping is
1116 /// * `asyncness`: Whether the function is async or not.
1117 crate fn full_print<'a, 'tcx: 'a>(
1121 asyncness: hir::IsAsync,
1122 cx: &'a Context<'tcx>,
1123 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1124 display_fn(move |f| self.inner_full_print(header_len, indent, asyncness, f, cx))
1127 fn inner_full_print(
1131 asyncness: hir::IsAsync,
1132 f: &mut fmt::Formatter<'_>,
1135 let amp = if f.alternate() { "&" } else { "&" };
1136 let mut args = String::new();
1137 let mut args_plain = String::new();
1138 for (i, input) in self.inputs.values.iter().enumerate() {
1140 args.push_str("<br>");
1143 if let Some(selfty) = input.to_self() {
1145 clean::SelfValue => {
1146 args.push_str("self");
1147 args_plain.push_str("self");
1149 clean::SelfBorrowed(Some(ref lt), mtbl) => {
1150 args.push_str(&format!(
1154 mtbl.print_with_space()
1156 args_plain.push_str(&format!(
1159 mtbl.print_with_space()
1162 clean::SelfBorrowed(None, mtbl) => {
1163 args.push_str(&format!("{}{}self", amp, mtbl.print_with_space()));
1164 args_plain.push_str(&format!("&{}self", mtbl.print_with_space()));
1166 clean::SelfExplicit(ref typ) => {
1168 args.push_str(&format!("self: {:#}", typ.print(cx)));
1170 args.push_str(&format!("self: {}", typ.print(cx)));
1172 args_plain.push_str(&format!("self: {:#}", typ.print(cx)));
1177 args.push_str(" <br>");
1178 args_plain.push(' ');
1180 if !input.name.is_empty() {
1181 args.push_str(&format!("{}: ", input.name));
1182 args_plain.push_str(&format!("{}: ", input.name));
1186 args.push_str(&format!("{:#}", input.type_.print(cx)));
1188 args.push_str(&input.type_.print(cx).to_string());
1190 args_plain.push_str(&format!("{:#}", input.type_.print(cx)));
1192 if i + 1 < self.inputs.values.len() {
1194 args_plain.push(',');
1198 let mut args_plain = format!("({})", args_plain);
1200 if self.c_variadic {
1201 args.push_str(",<br> ...");
1202 args_plain.push_str(", ...");
1206 let arrow = if let hir::IsAsync::Async = asyncness {
1207 let output = self.sugared_async_return_type();
1208 arrow_plain = format!("{:#}", output.print(cx));
1209 if f.alternate() { arrow_plain.clone() } else { format!("{}", output.print(cx)) }
1211 arrow_plain = format!("{:#}", self.output.print(cx));
1212 if f.alternate() { arrow_plain.clone() } else { format!("{}", self.output.print(cx)) }
1215 let declaration_len = header_len + args_plain.len() + arrow_plain.len();
1216 let output = if declaration_len > 80 {
1217 let full_pad = format!("<br>{}", " ".repeat(indent + 4));
1218 let close_pad = format!("<br>{}", " ".repeat(indent));
1220 "({args}{close}){arrow}",
1221 args = args.replace("<br>", &full_pad),
1226 format!("({args}){arrow}", args = args.replace("<br>", ""), arrow = arrow)
1230 write!(f, "{}", output.replace("<br>", "\n"))
1232 write!(f, "{}", output)
1237 impl clean::Visibility {
1238 crate fn print_with_space<'a, 'tcx: 'a>(
1241 cx: &'a Context<'tcx>,
1242 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1243 let to_print = match self {
1244 clean::Public => "pub ".to_owned(),
1245 clean::Inherited => String::new(),
1246 clean::Visibility::Restricted(vis_did) => {
1247 // FIXME(camelid): This may not work correctly if `item_did` is a module.
1248 // However, rustdoc currently never displays a module's
1249 // visibility, so it shouldn't matter.
1250 let parent_module = find_nearest_parent_module(cx.tcx(), item_did.expect_def_id());
1252 if vis_did.index == CRATE_DEF_INDEX {
1253 "pub(crate) ".to_owned()
1254 } else if parent_module == Some(vis_did) {
1255 // `pub(in foo)` where `foo` is the parent module
1256 // is the same as no visibility modifier
1258 } else if parent_module
1259 .map(|parent| find_nearest_parent_module(cx.tcx(), parent))
1263 "pub(super) ".to_owned()
1265 let path = cx.tcx().def_path(vis_did);
1266 debug!("path={:?}", path);
1267 // modified from `resolved_path()` to work with `DefPathData`
1268 let last_name = path.data.last().unwrap().data.get_opt_name().unwrap();
1269 let anchor = anchor(vis_did, &last_name.as_str(), cx).to_string();
1271 let mut s = "pub(in ".to_owned();
1272 for seg in &path.data[..path.data.len() - 1] {
1273 s.push_str(&format!("{}::", seg.data.get_opt_name().unwrap()));
1275 s.push_str(&format!("{}) ", anchor));
1280 display_fn(move |f| f.write_str(&to_print))
1283 /// This function is the same as print_with_space, except that it renders no links.
1284 /// It's used for macros' rendered source view, which is syntax highlighted and cannot have
1286 crate fn to_src_with_space<'a, 'tcx: 'a>(
1290 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1291 let to_print = match self {
1292 clean::Public => "pub ".to_owned(),
1293 clean::Inherited => String::new(),
1294 clean::Visibility::Restricted(vis_did) => {
1295 // FIXME(camelid): This may not work correctly if `item_did` is a module.
1296 // However, rustdoc currently never displays a module's
1297 // visibility, so it shouldn't matter.
1298 let parent_module = find_nearest_parent_module(tcx, item_did);
1300 if vis_did.index == CRATE_DEF_INDEX {
1301 "pub(crate) ".to_owned()
1302 } else if parent_module == Some(vis_did) {
1303 // `pub(in foo)` where `foo` is the parent module
1304 // is the same as no visibility modifier
1306 } else if parent_module
1307 .map(|parent| find_nearest_parent_module(tcx, parent))
1311 "pub(super) ".to_owned()
1313 format!("pub(in {}) ", tcx.def_path_str(vis_did))
1317 display_fn(move |f| f.write_str(&to_print))
1321 crate trait PrintWithSpace {
1322 fn print_with_space(&self) -> &str;
1325 impl PrintWithSpace for hir::Unsafety {
1326 fn print_with_space(&self) -> &str {
1328 hir::Unsafety::Unsafe => "unsafe ",
1329 hir::Unsafety::Normal => "",
1334 impl PrintWithSpace for hir::IsAsync {
1335 fn print_with_space(&self) -> &str {
1337 hir::IsAsync::Async => "async ",
1338 hir::IsAsync::NotAsync => "",
1343 impl PrintWithSpace for hir::Mutability {
1344 fn print_with_space(&self) -> &str {
1346 hir::Mutability::Not => "",
1347 hir::Mutability::Mut => "mut ",
1352 crate fn print_constness_with_space(c: &hir::Constness, s: Option<ConstStability>) -> &'static str {
1354 // const stable or when feature(staged_api) is not set
1356 hir::Constness::Const,
1357 Some(ConstStability { level: StabilityLevel::Stable { .. }, .. }),
1359 | (hir::Constness::Const, None) => "const ",
1360 // const unstable or not const
1365 impl clean::Import {
1366 crate fn print<'a, 'tcx: 'a>(
1368 cx: &'a Context<'tcx>,
1369 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1370 display_fn(move |f| match self.kind {
1371 clean::ImportKind::Simple(name) => {
1372 if name == self.source.path.last() {
1373 write!(f, "use {};", self.source.print(cx))
1375 write!(f, "use {} as {};", self.source.print(cx), name)
1378 clean::ImportKind::Glob => {
1379 if self.source.path.segments.is_empty() {
1382 write!(f, "use {}::*;", self.source.print(cx))
1389 impl clean::ImportSource {
1390 crate fn print<'a, 'tcx: 'a>(
1392 cx: &'a Context<'tcx>,
1393 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1394 display_fn(move |f| match self.did {
1395 Some(did) => resolved_path(f, did, &self.path, true, false, cx),
1397 for seg in &self.path.segments[..self.path.segments.len() - 1] {
1398 write!(f, "{}::", seg.name)?;
1400 let name = self.path.last_name();
1401 if let hir::def::Res::PrimTy(p) = self.path.res {
1402 primitive_link(f, PrimitiveType::from(p), &*name, cx)?;
1404 write!(f, "{}", name)?;
1412 impl clean::TypeBinding {
1413 crate fn print<'a, 'tcx: 'a>(
1415 cx: &'a Context<'tcx>,
1416 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1417 display_fn(move |f| {
1418 f.write_str(&*self.name.as_str())?;
1420 clean::TypeBindingKind::Equality { ref ty } => {
1422 write!(f, " = {:#}", ty.print(cx))?;
1424 write!(f, " = {}", ty.print(cx))?;
1427 clean::TypeBindingKind::Constraint { ref bounds } => {
1428 if !bounds.is_empty() {
1430 write!(f, ": {:#}", print_generic_bounds(bounds, cx))?;
1432 write!(f, ": {}", print_generic_bounds(bounds, cx))?;
1442 crate fn print_abi_with_space(abi: Abi) -> impl fmt::Display {
1443 display_fn(move |f| {
1444 let quot = if f.alternate() { "\"" } else { """ };
1446 Abi::Rust => Ok(()),
1447 abi => write!(f, "extern {0}{1}{0} ", quot, abi.name()),
1452 crate fn print_default_space<'a>(v: bool) -> &'a str {
1453 if v { "default " } else { "" }
1456 impl clean::GenericArg {
1457 crate fn print<'a, 'tcx: 'a>(
1459 cx: &'a Context<'tcx>,
1460 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1461 display_fn(move |f| match self {
1462 clean::GenericArg::Lifetime(lt) => fmt::Display::fmt(<.print(), f),
1463 clean::GenericArg::Type(ty) => fmt::Display::fmt(&ty.print(cx), f),
1464 clean::GenericArg::Const(ct) => fmt::Display::fmt(&ct.print(cx.tcx()), f),
1465 clean::GenericArg::Infer => fmt::Display::fmt("_", f),
1470 crate fn display_fn(f: impl FnOnce(&mut fmt::Formatter<'_>) -> fmt::Result) -> impl fmt::Display {
1471 struct WithFormatter<F>(Cell<Option<F>>);
1473 impl<F> fmt::Display for WithFormatter<F>
1475 F: FnOnce(&mut fmt::Formatter<'_>) -> fmt::Result,
1477 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1478 (self.0.take()).unwrap()(f)
1482 WithFormatter(Cell::new(Some(f)))