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;
30 use super::url_parts_builder::UrlPartsBuilder;
33 fn print(self, buffer: &mut Buffer);
38 F: FnOnce(&mut Buffer),
40 fn print(self, buffer: &mut Buffer) {
45 impl Print for String {
46 fn print(self, buffer: &mut Buffer) {
47 buffer.write_str(&self);
51 impl Print for &'_ str {
52 fn print(self, buffer: &mut Buffer) {
53 buffer.write_str(self);
57 #[derive(Debug, Clone)]
64 crate fn empty_from(v: &Buffer) -> Buffer {
65 Buffer { for_html: v.for_html, buffer: String::new() }
68 crate fn html() -> Buffer {
69 Buffer { for_html: true, buffer: String::new() }
72 crate fn new() -> Buffer {
73 Buffer { for_html: false, buffer: String::new() }
76 crate fn is_empty(&self) -> bool {
77 self.buffer.is_empty()
80 crate fn into_inner(self) -> String {
84 crate fn insert_str(&mut self, idx: usize, s: &str) {
85 self.buffer.insert_str(idx, s);
88 crate fn push_str(&mut self, s: &str) {
89 self.buffer.push_str(s);
92 crate fn push_buffer(&mut self, other: Buffer) {
93 self.buffer.push_str(&other.buffer);
96 // Intended for consumption by write! and writeln! (std::fmt) but without
97 // the fmt::Result return type imposed by fmt::Write (and avoiding the trait
99 crate fn write_str(&mut self, s: &str) {
100 self.buffer.push_str(s);
103 // Intended for consumption by write! and writeln! (std::fmt) but without
104 // the fmt::Result return type imposed by fmt::Write (and avoiding the trait
106 crate fn write_fmt(&mut self, v: fmt::Arguments<'_>) {
108 self.buffer.write_fmt(v).unwrap();
111 crate fn to_display<T: Print>(mut self, t: T) -> String {
116 crate fn is_for_html(&self) -> bool {
120 crate fn reserve(&mut self, additional: usize) {
121 self.buffer.reserve(additional)
125 fn comma_sep<T: fmt::Display>(items: impl Iterator<Item = T>) -> impl fmt::Display {
126 display_fn(move |f| {
127 for (i, item) in items.enumerate() {
131 fmt::Display::fmt(&item, f)?;
137 crate fn print_generic_bounds<'a, 'tcx: 'a>(
138 bounds: &'a [clean::GenericBound],
139 cx: &'a Context<'tcx>,
140 ) -> impl fmt::Display + 'a + Captures<'tcx> {
141 display_fn(move |f| {
142 let mut bounds_dup = FxHashSet::default();
145 bounds.iter().filter(|b| bounds_dup.insert(b.print(cx).to_string())).enumerate()
150 fmt::Display::fmt(&bound.print(cx), f)?;
156 impl clean::GenericParamDef {
157 crate fn print<'a, 'tcx: 'a>(
159 cx: &'a Context<'tcx>,
160 ) -> impl fmt::Display + 'a + Captures<'tcx> {
161 display_fn(move |f| match &self.kind {
162 clean::GenericParamDefKind::Lifetime { outlives } => {
163 write!(f, "{}", self.name)?;
165 if !outlives.is_empty() {
167 for (i, lt) in outlives.iter().enumerate() {
171 write!(f, "{}", lt.print())?;
177 clean::GenericParamDefKind::Type { bounds, default, .. } => {
178 f.write_str(self.name.as_str())?;
180 if !bounds.is_empty() {
182 write!(f, ": {:#}", print_generic_bounds(bounds, cx))?;
184 write!(f, ": {}", print_generic_bounds(bounds, cx))?;
188 if let Some(ref ty) = default {
190 write!(f, " = {:#}", ty.print(cx))?;
192 write!(f, " = {}", ty.print(cx))?;
198 clean::GenericParamDefKind::Const { ty, default, .. } => {
200 write!(f, "const {}: {:#}", self.name, ty.print(cx))?;
202 write!(f, "const {}: {}", self.name, ty.print(cx))?;
205 if let Some(default) = default {
207 write!(f, " = {:#}", default)?;
209 write!(f, " = {}", default)?;
219 impl clean::Generics {
220 crate fn print<'a, 'tcx: 'a>(
222 cx: &'a Context<'tcx>,
223 ) -> impl fmt::Display + 'a + Captures<'tcx> {
224 display_fn(move |f| {
225 let mut real_params =
226 self.params.iter().filter(|p| !p.is_synthetic_type_param()).peekable();
227 if real_params.peek().is_none() {
232 write!(f, "<{:#}>", comma_sep(real_params.map(|g| g.print(cx))))
234 write!(f, "<{}>", comma_sep(real_params.map(|g| g.print(cx))))
240 /// * The Generics from which to emit a where-clause.
241 /// * The number of spaces to indent each line with.
242 /// * Whether the where-clause needs to add a comma and newline after the last bound.
243 crate fn print_where_clause<'a, 'tcx: 'a>(
244 gens: &'a clean::Generics,
245 cx: &'a Context<'tcx>,
248 ) -> impl fmt::Display + 'a + Captures<'tcx> {
249 display_fn(move |f| {
250 if gens.where_predicates.is_empty() {
253 let mut clause = String::new();
255 clause.push_str(" where");
258 clause.push_str(" <span class=\"where fmt-newline\">where");
260 clause.push_str(" <span class=\"where\">where");
263 for (i, pred) in gens.where_predicates.iter().enumerate() {
267 clause.push_str("<br>");
271 clean::WherePredicate::BoundPredicate { ty, bounds, bound_params } => {
273 let for_prefix = match bound_params.len() {
275 _ if f.alternate() => {
278 comma_sep(bound_params.iter().map(|lt| lt.print()))
283 comma_sep(bound_params.iter().map(|lt| lt.print()))
288 clause.push_str(&format!(
292 print_generic_bounds(bounds, cx)
295 clause.push_str(&format!(
299 print_generic_bounds(bounds, cx)
303 clean::WherePredicate::RegionPredicate { lifetime, bounds } => {
304 clause.push_str(&format!(
309 .map(|b| b.print(cx).to_string())
314 clean::WherePredicate::EqPredicate { lhs, rhs } => {
316 clause.push_str(&format!("{:#} == {:#}", lhs.print(cx), rhs.print(cx),));
318 clause.push_str(&format!("{} == {}", lhs.print(cx), rhs.print(cx),));
323 if i < gens.where_predicates.len() - 1 || end_newline {
329 // add a space so stripping <br> tags and breaking spaces still renders properly
333 clause.push_str(" ");
338 clause.push_str("</span>");
339 let padding = " ".repeat(indent + 4);
340 clause = clause.replace("<br>", &format!("<br>{}", padding));
341 clause.insert_str(0, &" ".repeat(indent.saturating_sub(1)));
343 clause.insert_str(0, "<br>");
346 write!(f, "{}", clause)
350 impl clean::Lifetime {
351 crate fn print(&self) -> impl fmt::Display + '_ {
356 impl clean::Constant {
357 crate fn print(&self, tcx: TyCtxt<'_>) -> impl fmt::Display + '_ {
358 let expr = self.expr(tcx);
361 if f.alternate() { f.write_str(&expr) } else { write!(f, "{}", Escape(&expr)) }
367 impl clean::PolyTrait {
368 fn print<'a, 'tcx: 'a>(
370 cx: &'a Context<'tcx>,
371 ) -> impl fmt::Display + 'a + Captures<'tcx> {
372 display_fn(move |f| {
373 if !self.generic_params.is_empty() {
378 comma_sep(self.generic_params.iter().map(|g| g.print(cx)))
384 comma_sep(self.generic_params.iter().map(|g| g.print(cx)))
389 write!(f, "{:#}", self.trait_.print(cx))
391 write!(f, "{}", self.trait_.print(cx))
397 impl clean::GenericBound {
398 crate fn print<'a, 'tcx: 'a>(
400 cx: &'a Context<'tcx>,
401 ) -> impl fmt::Display + 'a + Captures<'tcx> {
402 display_fn(move |f| match self {
403 clean::GenericBound::Outlives(lt) => write!(f, "{}", lt.print()),
404 clean::GenericBound::TraitBound(ty, modifier) => {
405 let modifier_str = match modifier {
406 hir::TraitBoundModifier::None => "",
407 hir::TraitBoundModifier::Maybe => "?",
408 hir::TraitBoundModifier::MaybeConst => "~const",
411 write!(f, "{}{:#}", modifier_str, ty.print(cx))
413 write!(f, "{}{}", modifier_str, ty.print(cx))
420 impl clean::GenericArgs {
421 fn print<'a, 'tcx: 'a>(
423 cx: &'a Context<'tcx>,
424 ) -> impl fmt::Display + 'a + Captures<'tcx> {
425 display_fn(move |f| {
427 clean::GenericArgs::AngleBracketed { args, bindings } => {
428 if !args.is_empty() || !bindings.is_empty() {
432 f.write_str("<")?;
434 let mut comma = false;
441 write!(f, "{:#}", arg.print(cx))?;
443 write!(f, "{}", arg.print(cx))?;
446 for binding in bindings {
452 write!(f, "{:#}", binding.print(cx))?;
454 write!(f, "{}", binding.print(cx))?;
460 f.write_str(">")?;
464 clean::GenericArgs::Parenthesized { inputs, output } => {
466 let mut comma = false;
473 write!(f, "{:#}", ty.print(cx))?;
475 write!(f, "{}", ty.print(cx))?;
479 if let Some(ref ty) = *output {
481 write!(f, " -> {:#}", ty.print(cx))?;
483 write!(f, " -> {}", ty.print(cx))?;
493 // Possible errors when computing href link source for a `DefId`
494 crate enum HrefError {
495 /// This item is known to rustdoc, but from a crate that does not have documentation generated.
497 /// This can only happen for non-local items.
498 DocumentationNotBuilt,
499 /// This can only happen for non-local items when `--document-private-items` is not passed.
501 // Not in external cache, href link should be in same page
505 crate fn href_with_root_path(
508 root_path: Option<&str>,
509 ) -> Result<(String, ItemType, Vec<String>), HrefError> {
511 let def_kind = tcx.def_kind(did);
512 let did = match def_kind {
513 DefKind::AssocTy | DefKind::AssocFn | DefKind::AssocConst | DefKind::Variant => {
514 // documented on their parent's page
515 tcx.parent(did).unwrap()
519 let cache = cx.cache();
520 let relative_to = &cx.current;
521 fn to_module_fqp(shortty: ItemType, fqp: &[String]) -> &[String] {
522 if shortty == ItemType::Module { fqp } else { &fqp[..fqp.len() - 1] }
526 && !cache.access_levels.is_public(did)
527 && !cache.document_private
528 && !cache.primitive_locations.values().any(|&id| id == did)
530 return Err(HrefError::Private);
533 let mut is_remote = false;
534 let (fqp, shortty, mut url_parts) = match cache.paths.get(&did) {
535 Some(&(ref fqp, shortty)) => (fqp, shortty, {
536 let module_fqp = to_module_fqp(shortty, fqp);
537 debug!(?fqp, ?shortty, ?module_fqp);
538 href_relative_parts(module_fqp, relative_to)
541 if let Some(&(ref fqp, shortty)) = cache.external_paths.get(&did) {
542 let module_fqp = to_module_fqp(shortty, fqp);
546 match cache.extern_locations[&did.krate] {
547 ExternalLocation::Remote(ref s) => {
549 let s = s.trim_end_matches('/');
550 let mut builder = UrlPartsBuilder::singleton(s);
551 builder.extend(module_fqp.iter().map(String::as_str));
554 ExternalLocation::Local => href_relative_parts(module_fqp, relative_to),
555 ExternalLocation::Unknown => return Err(HrefError::DocumentationNotBuilt),
559 return Err(HrefError::NotInExternalCache);
564 if let Some(root_path) = root_path {
565 let root = root_path.trim_end_matches('/');
566 url_parts.push_front(root);
570 let last = &fqp.last().unwrap()[..];
572 ItemType::Module => {
573 url_parts.push("index.html");
576 let filename = format!("{}.{}.html", shortty.as_str(), last);
577 url_parts.push(&filename);
580 Ok((url_parts.finish(), shortty, fqp.to_vec()))
583 crate fn href(did: DefId, cx: &Context<'_>) -> Result<(String, ItemType, Vec<String>), HrefError> {
584 href_with_root_path(did, cx, None)
587 /// Both paths should only be modules.
588 /// This is because modules get their own directories; that is, `std::vec` and `std::vec::Vec` will
589 /// both need `../iter/trait.Iterator.html` to get at the iterator trait.
590 crate fn href_relative_parts(fqp: &[String], relative_to_fqp: &[String]) -> UrlPartsBuilder {
591 for (i, (f, r)) in fqp.iter().zip(relative_to_fqp.iter()).enumerate() {
592 // e.g. linking to std::iter from std::vec (`dissimilar_part_count` will be 1)
594 let dissimilar_part_count = relative_to_fqp.len() - i;
595 let fqp_module = fqp[i..fqp.len()].iter().map(String::as_str);
596 return iter::repeat("..").take(dissimilar_part_count).chain(fqp_module).collect();
599 // e.g. linking to std::sync::atomic from std::sync
600 if relative_to_fqp.len() < fqp.len() {
601 fqp[relative_to_fqp.len()..fqp.len()].iter().map(String::as_str).collect()
602 // e.g. linking to std::sync from std::sync::atomic
603 } else if fqp.len() < relative_to_fqp.len() {
604 let dissimilar_part_count = relative_to_fqp.len() - fqp.len();
605 iter::repeat("..").take(dissimilar_part_count).collect()
606 // linking to the same module
608 UrlPartsBuilder::new()
612 /// Used to render a [`clean::Path`].
613 fn resolved_path<'cx>(
614 w: &mut fmt::Formatter<'_>,
619 cx: &'cx Context<'_>,
621 let last = path.segments.last().unwrap();
624 for seg in &path.segments[..path.segments.len() - 1] {
625 write!(w, "{}::", seg.name)?;
629 write!(w, "{}{:#}", &last.name, last.args.print(cx))?;
631 let path = if use_absolute {
632 if let Ok((_, _, fqp)) = href(did, cx) {
635 fqp[..fqp.len() - 1].join("::"),
636 anchor(did, fqp.last().unwrap(), cx)
639 last.name.to_string()
642 anchor(did, last.name.as_str(), cx).to_string()
644 write!(w, "{}{}", path, last.args.print(cx))?;
650 f: &mut fmt::Formatter<'_>,
651 prim: clean::PrimitiveType,
656 let mut needs_termination = false;
658 match m.primitive_locations.get(&prim) {
659 Some(&def_id) if def_id.is_local() => {
660 let len = cx.current.len();
661 let len = if len == 0 { 0 } else { len - 1 };
664 "<a class=\"primitive\" href=\"{}primitive.{}.html\">",
668 needs_termination = true;
672 let loc = match m.extern_locations[&def_id.krate] {
673 ExternalLocation::Remote(ref s) => {
674 cname_sym = ExternalCrate { crate_num: def_id.krate }.name(cx.tcx());
675 Some(vec![s.trim_end_matches('/'), cname_sym.as_str()])
677 ExternalLocation::Local => {
678 cname_sym = ExternalCrate { crate_num: def_id.krate }.name(cx.tcx());
679 Some(if cx.current.first().map(|x| &x[..]) == Some(cname_sym.as_str()) {
680 iter::repeat("..").take(cx.current.len() - 1).collect()
682 let cname = iter::once(cname_sym.as_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(' ');
1181 args.push_str("const ");
1182 args_plain.push_str("const ");
1184 if !input.name.is_empty() {
1185 args.push_str(&format!("{}: ", input.name));
1186 args_plain.push_str(&format!("{}: ", input.name));
1190 args.push_str(&format!("{:#}", input.type_.print(cx)));
1192 args.push_str(&input.type_.print(cx).to_string());
1194 args_plain.push_str(&format!("{:#}", input.type_.print(cx)));
1196 if i + 1 < self.inputs.values.len() {
1198 args_plain.push(',');
1202 let mut args_plain = format!("({})", args_plain);
1204 if self.c_variadic {
1205 args.push_str(",<br> ...");
1206 args_plain.push_str(", ...");
1210 let arrow = if let hir::IsAsync::Async = asyncness {
1211 let output = self.sugared_async_return_type();
1212 arrow_plain = format!("{:#}", output.print(cx));
1213 if f.alternate() { arrow_plain.clone() } else { format!("{}", output.print(cx)) }
1215 arrow_plain = format!("{:#}", self.output.print(cx));
1216 if f.alternate() { arrow_plain.clone() } else { format!("{}", self.output.print(cx)) }
1219 let declaration_len = header_len + args_plain.len() + arrow_plain.len();
1220 let output = if declaration_len > 80 {
1221 let full_pad = format!("<br>{}", " ".repeat(indent + 4));
1222 let close_pad = format!("<br>{}", " ".repeat(indent));
1224 "({args}{close}){arrow}",
1225 args = args.replace("<br>", &full_pad),
1230 format!("({args}){arrow}", args = args.replace("<br>", ""), arrow = arrow)
1234 write!(f, "{}", output.replace("<br>", "\n"))
1236 write!(f, "{}", output)
1241 impl clean::Visibility {
1242 crate fn print_with_space<'a, 'tcx: 'a>(
1245 cx: &'a Context<'tcx>,
1246 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1247 let to_print = match self {
1248 clean::Public => "pub ".to_owned(),
1249 clean::Inherited => String::new(),
1250 clean::Visibility::Restricted(vis_did) => {
1251 // FIXME(camelid): This may not work correctly if `item_did` is a module.
1252 // However, rustdoc currently never displays a module's
1253 // visibility, so it shouldn't matter.
1254 let parent_module = find_nearest_parent_module(cx.tcx(), item_did.expect_def_id());
1256 if vis_did.index == CRATE_DEF_INDEX {
1257 "pub(crate) ".to_owned()
1258 } else if parent_module == Some(vis_did) {
1259 // `pub(in foo)` where `foo` is the parent module
1260 // is the same as no visibility modifier
1262 } else if parent_module
1263 .map(|parent| find_nearest_parent_module(cx.tcx(), parent))
1267 "pub(super) ".to_owned()
1269 let path = cx.tcx().def_path(vis_did);
1270 debug!("path={:?}", path);
1271 // modified from `resolved_path()` to work with `DefPathData`
1272 let last_name = path.data.last().unwrap().data.get_opt_name().unwrap();
1273 let anchor = anchor(vis_did, last_name.as_str(), cx).to_string();
1275 let mut s = "pub(in ".to_owned();
1276 for seg in &path.data[..path.data.len() - 1] {
1277 s.push_str(&format!("{}::", seg.data.get_opt_name().unwrap()));
1279 s.push_str(&format!("{}) ", anchor));
1284 display_fn(move |f| f.write_str(&to_print))
1287 /// This function is the same as print_with_space, except that it renders no links.
1288 /// It's used for macros' rendered source view, which is syntax highlighted and cannot have
1290 crate fn to_src_with_space<'a, 'tcx: 'a>(
1294 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1295 let to_print = match self {
1296 clean::Public => "pub ".to_owned(),
1297 clean::Inherited => String::new(),
1298 clean::Visibility::Restricted(vis_did) => {
1299 // FIXME(camelid): This may not work correctly if `item_did` is a module.
1300 // However, rustdoc currently never displays a module's
1301 // visibility, so it shouldn't matter.
1302 let parent_module = find_nearest_parent_module(tcx, item_did);
1304 if vis_did.index == CRATE_DEF_INDEX {
1305 "pub(crate) ".to_owned()
1306 } else if parent_module == Some(vis_did) {
1307 // `pub(in foo)` where `foo` is the parent module
1308 // is the same as no visibility modifier
1310 } else if parent_module
1311 .map(|parent| find_nearest_parent_module(tcx, parent))
1315 "pub(super) ".to_owned()
1317 format!("pub(in {}) ", tcx.def_path_str(vis_did))
1321 display_fn(move |f| f.write_str(&to_print))
1325 crate trait PrintWithSpace {
1326 fn print_with_space(&self) -> &str;
1329 impl PrintWithSpace for hir::Unsafety {
1330 fn print_with_space(&self) -> &str {
1332 hir::Unsafety::Unsafe => "unsafe ",
1333 hir::Unsafety::Normal => "",
1338 impl PrintWithSpace for hir::IsAsync {
1339 fn print_with_space(&self) -> &str {
1341 hir::IsAsync::Async => "async ",
1342 hir::IsAsync::NotAsync => "",
1347 impl PrintWithSpace for hir::Mutability {
1348 fn print_with_space(&self) -> &str {
1350 hir::Mutability::Not => "",
1351 hir::Mutability::Mut => "mut ",
1356 crate fn print_constness_with_space(c: &hir::Constness, s: Option<ConstStability>) -> &'static str {
1358 // const stable or when feature(staged_api) is not set
1360 hir::Constness::Const,
1361 Some(ConstStability { level: StabilityLevel::Stable { .. }, .. }),
1363 | (hir::Constness::Const, None) => "const ",
1364 // const unstable or not const
1369 impl clean::Import {
1370 crate fn print<'a, 'tcx: 'a>(
1372 cx: &'a Context<'tcx>,
1373 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1374 display_fn(move |f| match self.kind {
1375 clean::ImportKind::Simple(name) => {
1376 if name == self.source.path.last() {
1377 write!(f, "use {};", self.source.print(cx))
1379 write!(f, "use {} as {};", self.source.print(cx), name)
1382 clean::ImportKind::Glob => {
1383 if self.source.path.segments.is_empty() {
1386 write!(f, "use {}::*;", self.source.print(cx))
1393 impl clean::ImportSource {
1394 crate fn print<'a, 'tcx: 'a>(
1396 cx: &'a Context<'tcx>,
1397 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1398 display_fn(move |f| match self.did {
1399 Some(did) => resolved_path(f, did, &self.path, true, false, cx),
1401 for seg in &self.path.segments[..self.path.segments.len() - 1] {
1402 write!(f, "{}::", seg.name)?;
1404 let name = self.path.last();
1405 if let hir::def::Res::PrimTy(p) = self.path.res {
1406 primitive_link(f, PrimitiveType::from(p), name.as_str(), cx)?;
1408 write!(f, "{}", name)?;
1416 impl clean::TypeBinding {
1417 crate fn print<'a, 'tcx: 'a>(
1419 cx: &'a Context<'tcx>,
1420 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1421 display_fn(move |f| {
1422 f.write_str(self.name.as_str())?;
1424 clean::TypeBindingKind::Equality { ref ty } => {
1426 write!(f, " = {:#}", ty.print(cx))?;
1428 write!(f, " = {}", ty.print(cx))?;
1431 clean::TypeBindingKind::Constraint { ref bounds } => {
1432 if !bounds.is_empty() {
1434 write!(f, ": {:#}", print_generic_bounds(bounds, cx))?;
1436 write!(f, ": {}", print_generic_bounds(bounds, cx))?;
1446 crate fn print_abi_with_space(abi: Abi) -> impl fmt::Display {
1447 display_fn(move |f| {
1448 let quot = if f.alternate() { "\"" } else { """ };
1450 Abi::Rust => Ok(()),
1451 abi => write!(f, "extern {0}{1}{0} ", quot, abi.name()),
1456 crate fn print_default_space<'a>(v: bool) -> &'a str {
1457 if v { "default " } else { "" }
1460 impl clean::GenericArg {
1461 crate fn print<'a, 'tcx: 'a>(
1463 cx: &'a Context<'tcx>,
1464 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1465 display_fn(move |f| match self {
1466 clean::GenericArg::Lifetime(lt) => fmt::Display::fmt(<.print(), f),
1467 clean::GenericArg::Type(ty) => fmt::Display::fmt(&ty.print(cx), f),
1468 clean::GenericArg::Const(ct) => fmt::Display::fmt(&ct.print(cx.tcx()), f),
1469 clean::GenericArg::Infer => fmt::Display::fmt("_", f),
1474 crate fn display_fn(f: impl FnOnce(&mut fmt::Formatter<'_>) -> fmt::Result) -> impl fmt::Display {
1475 struct WithFormatter<F>(Cell<Option<F>>);
1477 impl<F> fmt::Display for WithFormatter<F>
1479 F: FnOnce(&mut fmt::Formatter<'_>) -> fmt::Result,
1481 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1482 (self.0.take()).unwrap()(f)
1486 WithFormatter(Cell::new(Some(f)))