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| {
226 self.params.iter().filter(|p| !p.is_synthetic_type_param()).collect::<Vec<_>>();
227 if real_params.is_empty() {
231 write!(f, "<{:#}>", comma_sep(real_params.iter().map(|g| g.print(cx))))
233 write!(f, "<{}>", comma_sep(real_params.iter().map(|g| g.print(cx))))
239 /// * The Generics from which to emit a where-clause.
240 /// * The number of spaces to indent each line with.
241 /// * Whether the where-clause needs to add a comma and newline after the last bound.
242 crate fn print_where_clause<'a, 'tcx: 'a>(
243 gens: &'a clean::Generics,
244 cx: &'a Context<'tcx>,
247 ) -> impl fmt::Display + 'a + Captures<'tcx> {
248 display_fn(move |f| {
249 if gens.where_predicates.is_empty() {
252 let mut clause = String::new();
254 clause.push_str(" where");
257 clause.push_str(" <span class=\"where fmt-newline\">where");
259 clause.push_str(" <span class=\"where\">where");
262 for (i, pred) in gens.where_predicates.iter().enumerate() {
266 clause.push_str("<br>");
270 clean::WherePredicate::BoundPredicate { ty, bounds, bound_params } => {
272 let for_prefix = match bound_params.len() {
274 _ if f.alternate() => {
277 comma_sep(bound_params.iter().map(|lt| lt.print()))
282 comma_sep(bound_params.iter().map(|lt| lt.print()))
287 clause.push_str(&format!(
291 print_generic_bounds(bounds, cx)
294 clause.push_str(&format!(
298 print_generic_bounds(bounds, cx)
302 clean::WherePredicate::RegionPredicate { lifetime, bounds } => {
303 clause.push_str(&format!(
308 .map(|b| b.print(cx).to_string())
313 clean::WherePredicate::EqPredicate { lhs, rhs } => {
315 clause.push_str(&format!("{:#} == {:#}", lhs.print(cx), rhs.print(cx),));
317 clause.push_str(&format!("{} == {}", lhs.print(cx), rhs.print(cx),));
322 if i < gens.where_predicates.len() - 1 || end_newline {
328 // add a space so stripping <br> tags and breaking spaces still renders properly
332 clause.push_str(" ");
337 clause.push_str("</span>");
338 let padding = " ".repeat(indent + 4);
339 clause = clause.replace("<br>", &format!("<br>{}", padding));
340 clause.insert_str(0, &" ".repeat(indent.saturating_sub(1)));
342 clause.insert_str(0, "<br>");
345 write!(f, "{}", clause)
349 impl clean::Lifetime {
350 crate fn print(&self) -> impl fmt::Display + '_ {
355 impl clean::Constant {
356 crate fn print(&self, tcx: TyCtxt<'_>) -> impl fmt::Display + '_ {
357 let expr = self.expr(tcx);
360 if f.alternate() { f.write_str(&expr) } else { write!(f, "{}", Escape(&expr)) }
366 impl clean::PolyTrait {
367 fn print<'a, 'tcx: 'a>(
369 cx: &'a Context<'tcx>,
370 ) -> impl fmt::Display + 'a + Captures<'tcx> {
371 display_fn(move |f| {
372 if !self.generic_params.is_empty() {
377 comma_sep(self.generic_params.iter().map(|g| g.print(cx)))
383 comma_sep(self.generic_params.iter().map(|g| g.print(cx)))
388 write!(f, "{:#}", self.trait_.print(cx))
390 write!(f, "{}", self.trait_.print(cx))
396 impl clean::GenericBound {
397 crate fn print<'a, 'tcx: 'a>(
399 cx: &'a Context<'tcx>,
400 ) -> impl fmt::Display + 'a + Captures<'tcx> {
401 display_fn(move |f| match self {
402 clean::GenericBound::Outlives(lt) => write!(f, "{}", lt.print()),
403 clean::GenericBound::TraitBound(ty, modifier) => {
404 let modifier_str = match modifier {
405 hir::TraitBoundModifier::None => "",
406 hir::TraitBoundModifier::Maybe => "?",
407 hir::TraitBoundModifier::MaybeConst => "~const",
410 write!(f, "{}{:#}", modifier_str, ty.print(cx))
412 write!(f, "{}{}", modifier_str, ty.print(cx))
419 impl clean::GenericArgs {
420 fn print<'a, 'tcx: 'a>(
422 cx: &'a Context<'tcx>,
423 ) -> impl fmt::Display + 'a + Captures<'tcx> {
424 display_fn(move |f| {
426 clean::GenericArgs::AngleBracketed { args, bindings } => {
427 if !args.is_empty() || !bindings.is_empty() {
431 f.write_str("<")?;
433 let mut comma = false;
440 write!(f, "{:#}", arg.print(cx))?;
442 write!(f, "{}", arg.print(cx))?;
445 for binding in bindings {
451 write!(f, "{:#}", binding.print(cx))?;
453 write!(f, "{}", binding.print(cx))?;
459 f.write_str(">")?;
463 clean::GenericArgs::Parenthesized { inputs, output } => {
465 let mut comma = false;
472 write!(f, "{:#}", ty.print(cx))?;
474 write!(f, "{}", ty.print(cx))?;
478 if let Some(ref ty) = *output {
480 write!(f, " -> {:#}", ty.print(cx))?;
482 write!(f, " -> {}", ty.print(cx))?;
492 // Possible errors when computing href link source for a `DefId`
493 crate enum HrefError {
494 /// This item is known to rustdoc, but from a crate that does not have documentation generated.
496 /// This can only happen for non-local items.
497 DocumentationNotBuilt,
498 /// This can only happen for non-local items when `--document-private-items` is not passed.
500 // Not in external cache, href link should be in same page
504 crate fn href_with_root_path(
507 root_path: Option<&str>,
508 ) -> Result<(String, ItemType, Vec<String>), HrefError> {
510 let def_kind = tcx.def_kind(did);
511 let did = match def_kind {
512 DefKind::AssocTy | DefKind::AssocFn | DefKind::AssocConst | DefKind::Variant => {
513 // documented on their parent's page
514 tcx.parent(did).unwrap()
518 let cache = cx.cache();
519 let relative_to = &cx.current;
520 fn to_module_fqp(shortty: ItemType, fqp: &[String]) -> &[String] {
521 if shortty == ItemType::Module { fqp } else { &fqp[..fqp.len() - 1] }
525 && !cache.access_levels.is_public(did)
526 && !cache.document_private
527 && !cache.primitive_locations.values().any(|&id| id == did)
529 return Err(HrefError::Private);
532 let mut is_remote = false;
533 let (fqp, shortty, mut url_parts) = match cache.paths.get(&did) {
534 Some(&(ref fqp, shortty)) => (fqp, shortty, {
535 let module_fqp = to_module_fqp(shortty, fqp);
536 debug!(?fqp, ?shortty, ?module_fqp);
537 href_relative_parts(module_fqp, relative_to)
540 if let Some(&(ref fqp, shortty)) = cache.external_paths.get(&did) {
541 let module_fqp = to_module_fqp(shortty, fqp);
545 match cache.extern_locations[&did.krate] {
546 ExternalLocation::Remote(ref s) => {
548 let s = s.trim_end_matches('/');
549 let mut builder = UrlPartsBuilder::singleton(s);
550 builder.extend(module_fqp.iter().map(String::as_str));
553 ExternalLocation::Local => href_relative_parts(module_fqp, relative_to),
554 ExternalLocation::Unknown => return Err(HrefError::DocumentationNotBuilt),
558 return Err(HrefError::NotInExternalCache);
563 if let Some(root_path) = root_path {
564 let root = root_path.trim_end_matches('/');
565 url_parts.push_front(root);
569 let last = &fqp.last().unwrap()[..];
571 ItemType::Module => {
572 url_parts.push("index.html");
575 let filename = format!("{}.{}.html", shortty.as_str(), last);
576 url_parts.push(&filename);
579 Ok((url_parts.finish(), shortty, fqp.to_vec()))
582 crate fn href(did: DefId, cx: &Context<'_>) -> Result<(String, ItemType, Vec<String>), HrefError> {
583 href_with_root_path(did, cx, None)
586 /// Both paths should only be modules.
587 /// This is because modules get their own directories; that is, `std::vec` and `std::vec::Vec` will
588 /// both need `../iter/trait.Iterator.html` to get at the iterator trait.
589 crate fn href_relative_parts(fqp: &[String], relative_to_fqp: &[String]) -> UrlPartsBuilder {
590 for (i, (f, r)) in fqp.iter().zip(relative_to_fqp.iter()).enumerate() {
591 // e.g. linking to std::iter from std::vec (`dissimilar_part_count` will be 1)
593 let dissimilar_part_count = relative_to_fqp.len() - i;
594 let fqp_module = fqp[i..fqp.len()].iter().map(String::as_str);
595 return iter::repeat("..").take(dissimilar_part_count).chain(fqp_module).collect();
598 // e.g. linking to std::sync::atomic from std::sync
599 if relative_to_fqp.len() < fqp.len() {
600 fqp[relative_to_fqp.len()..fqp.len()].iter().map(String::as_str).collect()
601 // e.g. linking to std::sync from std::sync::atomic
602 } else if fqp.len() < relative_to_fqp.len() {
603 let dissimilar_part_count = relative_to_fqp.len() - fqp.len();
604 iter::repeat("..").take(dissimilar_part_count).collect()
605 // linking to the same module
607 UrlPartsBuilder::new()
611 /// Used to render a [`clean::Path`].
612 fn resolved_path<'cx>(
613 w: &mut fmt::Formatter<'_>,
618 cx: &'cx Context<'_>,
620 let last = path.segments.last().unwrap();
623 for seg in &path.segments[..path.segments.len() - 1] {
624 write!(w, "{}::", seg.name)?;
628 write!(w, "{}{:#}", &last.name, last.args.print(cx))?;
630 let path = if use_absolute {
631 if let Ok((_, _, fqp)) = href(did, cx) {
634 fqp[..fqp.len() - 1].join("::"),
635 anchor(did, fqp.last().unwrap(), cx)
638 last.name.to_string()
641 anchor(did, &*last.name.as_str(), cx).to_string()
643 write!(w, "{}{}", path, last.args.print(cx))?;
649 f: &mut fmt::Formatter<'_>,
650 prim: clean::PrimitiveType,
655 let mut needs_termination = false;
657 match m.primitive_locations.get(&prim) {
658 Some(&def_id) if def_id.is_local() => {
659 let len = cx.current.len();
660 let len = if len == 0 { 0 } else { len - 1 };
663 "<a class=\"primitive\" href=\"{}primitive.{}.html\">",
667 needs_termination = true;
671 let loc = match m.extern_locations[&def_id.krate] {
672 ExternalLocation::Remote(ref s) => {
674 ExternalCrate { crate_num: def_id.krate }.name(cx.tcx()).as_str();
675 Some(vec![s.trim_end_matches('/'), &cname_str[..]])
677 ExternalLocation::Local => {
679 ExternalCrate { crate_num: def_id.krate }.name(cx.tcx()).as_str();
680 Some(if cx.current.first().map(|x| &x[..]) == Some(&cname_str[..]) {
681 iter::repeat("..").take(cx.current.len() - 1).collect()
683 let cname = iter::once(&cname_str[..]);
684 iter::repeat("..").take(cx.current.len()).chain(cname).collect()
687 ExternalLocation::Unknown => None,
689 if let Some(loc) = loc {
692 "<a class=\"primitive\" href=\"{}/primitive.{}.html\">",
696 needs_termination = true;
702 write!(f, "{}", name)?;
703 if needs_termination {
709 /// Helper to render type parameters
710 fn tybounds<'a, 'tcx: 'a>(
711 bounds: &'a [clean::PolyTrait],
712 lt: &'a Option<clean::Lifetime>,
713 cx: &'a Context<'tcx>,
714 ) -> impl fmt::Display + 'a + Captures<'tcx> {
715 display_fn(move |f| {
716 for (i, bound) in bounds.iter().enumerate() {
721 fmt::Display::fmt(&bound.print(cx), f)?;
724 if let Some(lt) = lt {
726 fmt::Display::fmt(<.print(), f)?;
732 crate fn anchor<'a, 'cx: 'a>(
735 cx: &'cx Context<'_>,
736 ) -> impl fmt::Display + 'a {
737 let parts = href(did, cx);
738 display_fn(move |f| {
739 if let Ok((url, short_ty, fqp)) = parts {
742 r#"<a class="{}" href="{}" title="{} {}">{}</a>"#,
750 write!(f, "{}", text)
757 f: &mut fmt::Formatter<'_>,
759 cx: &'cx Context<'_>,
761 trace!("fmt_type(t = {:?})", t);
764 clean::Generic(name) => write!(f, "{}", name),
765 clean::Type::Path { ref path } => {
766 // Paths like `T::Output` and `Self::Output` should be rendered with all segments.
767 let did = path.def_id();
768 resolved_path(f, did, path, path.is_assoc_ty(), use_absolute, cx)
770 clean::DynTrait(ref bounds, ref lt) => {
771 f.write_str("dyn ")?;
772 fmt::Display::fmt(&tybounds(bounds, lt, cx), f)
774 clean::Infer => write!(f, "_"),
775 clean::Primitive(clean::PrimitiveType::Never) => {
776 primitive_link(f, PrimitiveType::Never, "!", cx)
778 clean::Primitive(prim) => primitive_link(f, prim, &*prim.as_sym().as_str(), cx),
779 clean::BareFunction(ref decl) => {
784 decl.print_hrtb_with_space(cx),
785 decl.unsafety.print_with_space(),
786 print_abi_with_space(decl.abi),
793 decl.print_hrtb_with_space(cx),
794 decl.unsafety.print_with_space(),
795 print_abi_with_space(decl.abi)
797 primitive_link(f, PrimitiveType::Fn, "fn", cx)?;
798 write!(f, "{}", decl.decl.print(cx))
801 clean::Tuple(ref typs) => {
803 &[] => primitive_link(f, PrimitiveType::Unit, "()", cx),
805 primitive_link(f, PrimitiveType::Tuple, "(", cx)?;
806 // Carry `f.alternate()` into this display w/o branching manually.
807 fmt::Display::fmt(&one.print(cx), f)?;
808 primitive_link(f, PrimitiveType::Tuple, ",)", cx)
811 primitive_link(f, PrimitiveType::Tuple, "(", cx)?;
812 for (i, item) in many.iter().enumerate() {
816 fmt::Display::fmt(&item.print(cx), f)?;
818 primitive_link(f, PrimitiveType::Tuple, ")", cx)
822 clean::Slice(ref t) => {
823 primitive_link(f, PrimitiveType::Slice, "[", cx)?;
824 fmt::Display::fmt(&t.print(cx), f)?;
825 primitive_link(f, PrimitiveType::Slice, "]", cx)
827 clean::Array(ref t, ref n) => {
828 primitive_link(f, PrimitiveType::Array, "[", cx)?;
829 fmt::Display::fmt(&t.print(cx), f)?;
831 primitive_link(f, PrimitiveType::Array, &format!("; {}]", n), cx)
833 primitive_link(f, PrimitiveType::Array, &format!("; {}]", Escape(n)), cx)
836 clean::RawPointer(m, ref t) => {
838 hir::Mutability::Mut => "mut",
839 hir::Mutability::Not => "const",
842 if matches!(**t, clean::Generic(_)) || t.is_assoc_ty() {
843 let text = if f.alternate() {
844 format!("*{} {:#}", m, t.print(cx))
846 format!("*{} {}", m, t.print(cx))
848 primitive_link(f, clean::PrimitiveType::RawPointer, &text, cx)
850 primitive_link(f, clean::PrimitiveType::RawPointer, &format!("*{} ", m), cx)?;
851 fmt::Display::fmt(&t.print(cx), f)
854 clean::BorrowedRef { lifetime: ref l, mutability, type_: ref ty } => {
856 Some(l) => format!("{} ", l.print()),
859 let m = mutability.print_with_space();
860 let amp = if f.alternate() { "&".to_string() } else { "&".to_string() };
862 clean::Slice(ref bt) => {
863 // `BorrowedRef{ ... Slice(T) }` is `&[T]`
865 clean::Generic(_) => {
869 PrimitiveType::Slice,
870 &format!("{}{}{}[{:#}]", amp, lt, m, bt.print(cx)),
876 PrimitiveType::Slice,
877 &format!("{}{}{}[{}]", amp, lt, m, bt.print(cx)),
885 PrimitiveType::Slice,
886 &format!("{}{}{}[", amp, lt, m),
890 write!(f, "{:#}", bt.print(cx))?;
892 write!(f, "{}", bt.print(cx))?;
894 primitive_link(f, PrimitiveType::Slice, "]", cx)
898 clean::DynTrait(ref bounds, ref trait_lt)
899 if bounds.len() > 1 || trait_lt.is_some() =>
901 write!(f, "{}{}{}(", amp, lt, m)?;
902 fmt_type(ty, f, use_absolute, cx)?;
905 clean::Generic(..) => {
908 PrimitiveType::Reference,
909 &format!("{}{}{}", amp, lt, m),
912 fmt_type(ty, f, use_absolute, cx)
915 write!(f, "{}{}{}", amp, lt, m)?;
916 fmt_type(ty, f, use_absolute, cx)
920 clean::ImplTrait(ref bounds) => {
922 write!(f, "impl {:#}", print_generic_bounds(bounds, cx))
924 write!(f, "impl {}", print_generic_bounds(bounds, cx))
927 clean::QPath { ref name, ref self_type, ref trait_, ref self_def_id } => {
928 let should_show_cast = !trait_.segments.is_empty()
930 .zip(Some(trait_.def_id()))
931 .map_or(!self_type.is_self_type(), |(id, trait_)| id != trait_);
933 if should_show_cast {
934 write!(f, "<{:#} as {:#}>::", self_type.print(cx), trait_.print(cx))?
936 write!(f, "{:#}::", self_type.print(cx))?
939 if should_show_cast {
940 write!(f, "<{} as {}>::", self_type.print(cx), trait_.print(cx))?
942 write!(f, "{}::", self_type.print(cx))?
945 // It's pretty unsightly to look at `<A as B>::C` in output, and
946 // we've got hyperlinking on our side, so try to avoid longer
947 // notation as much as possible by making `C` a hyperlink to trait
948 // `B` to disambiguate.
950 // FIXME: this is still a lossy conversion and there should probably
951 // be a better way of representing this in general? Most of
952 // the ugliness comes from inlining across crates where
953 // everything comes in as a fully resolved QPath (hard to
955 match href(trait_.def_id(), cx) {
956 Ok((ref url, _, ref path)) if !f.alternate() => {
959 "<a class=\"type\" href=\"{url}#{shortty}.{name}\" \
960 title=\"type {path}::{name}\">{name}</a>",
962 shortty = ItemType::AssocType,
964 path = path.join("::")
967 _ => write!(f, "{}", name)?,
975 crate fn print<'b, 'a: 'b, 'tcx: 'a>(
977 cx: &'a Context<'tcx>,
978 ) -> impl fmt::Display + 'b + Captures<'tcx> {
979 display_fn(move |f| fmt_type(self, f, false, cx))
984 crate fn print<'b, 'a: 'b, 'tcx: 'a>(
986 cx: &'a Context<'tcx>,
987 ) -> impl fmt::Display + 'b + Captures<'tcx> {
988 display_fn(move |f| resolved_path(f, self.def_id(), self, false, false, cx))
993 crate fn print<'a, 'tcx: 'a>(
996 cx: &'a Context<'tcx>,
997 ) -> impl fmt::Display + 'a + Captures<'tcx> {
998 display_fn(move |f| {
1000 write!(f, "impl{:#} ", self.generics.print(cx))?;
1002 write!(f, "impl{} ", self.generics.print(cx))?;
1005 if let Some(ref ty) = self.trait_ {
1006 match self.polarity {
1007 ty::ImplPolarity::Positive | ty::ImplPolarity::Reservation => {}
1008 ty::ImplPolarity::Negative => write!(f, "!")?,
1010 fmt::Display::fmt(&ty.print(cx), f)?;
1011 write!(f, " for ")?;
1014 if let Some(ref ty) = self.kind.as_blanket_ty() {
1015 fmt_type(ty, f, use_absolute, cx)?;
1017 fmt_type(&self.for_, f, use_absolute, cx)?;
1020 fmt::Display::fmt(&print_where_clause(&self.generics, cx, 0, true), f)?;
1026 impl clean::Arguments {
1027 crate fn print<'a, 'tcx: 'a>(
1029 cx: &'a Context<'tcx>,
1030 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1031 display_fn(move |f| {
1032 for (i, input) in self.values.iter().enumerate() {
1033 if !input.name.is_empty() {
1034 write!(f, "{}: ", input.name)?;
1037 write!(f, "{:#}", input.type_.print(cx))?;
1039 write!(f, "{}", input.type_.print(cx))?;
1041 if i + 1 < self.values.len() {
1050 impl clean::FnRetTy {
1051 crate fn print<'a, 'tcx: 'a>(
1053 cx: &'a Context<'tcx>,
1054 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1055 display_fn(move |f| match self {
1056 clean::Return(clean::Tuple(tys)) if tys.is_empty() => Ok(()),
1057 clean::Return(ty) if f.alternate() => {
1058 write!(f, " -> {:#}", ty.print(cx))
1060 clean::Return(ty) => write!(f, " -> {}", ty.print(cx)),
1061 clean::DefaultReturn => Ok(()),
1066 impl clean::BareFunctionDecl {
1067 fn print_hrtb_with_space<'a, 'tcx: 'a>(
1069 cx: &'a Context<'tcx>,
1070 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1071 display_fn(move |f| {
1072 if !self.generic_params.is_empty() {
1076 comma_sep(self.generic_params.iter().map(|g| g.print(cx)))
1085 impl clean::FnDecl {
1086 crate fn print<'b, 'a: 'b, 'tcx: 'a>(
1088 cx: &'a Context<'tcx>,
1089 ) -> impl fmt::Display + 'b + Captures<'tcx> {
1090 display_fn(move |f| {
1091 let ellipsis = if self.c_variadic { ", ..." } else { "" };
1095 "({args:#}{ellipsis}){arrow:#}",
1096 args = self.inputs.print(cx),
1097 ellipsis = ellipsis,
1098 arrow = self.output.print(cx)
1103 "({args}{ellipsis}){arrow}",
1104 args = self.inputs.print(cx),
1105 ellipsis = ellipsis,
1106 arrow = self.output.print(cx)
1112 /// * `header_len`: The length of the function header and name. In other words, the number of
1113 /// characters in the function declaration up to but not including the parentheses.
1114 /// <br>Used to determine line-wrapping.
1115 /// * `indent`: The number of spaces to indent each successive line with, if line-wrapping is
1117 /// * `asyncness`: Whether the function is async or not.
1118 crate fn full_print<'a, 'tcx: 'a>(
1122 asyncness: hir::IsAsync,
1123 cx: &'a Context<'tcx>,
1124 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1125 display_fn(move |f| self.inner_full_print(header_len, indent, asyncness, f, cx))
1128 fn inner_full_print(
1132 asyncness: hir::IsAsync,
1133 f: &mut fmt::Formatter<'_>,
1136 let amp = if f.alternate() { "&" } else { "&" };
1137 let mut args = String::new();
1138 let mut args_plain = String::new();
1139 for (i, input) in self.inputs.values.iter().enumerate() {
1141 args.push_str("<br>");
1144 if let Some(selfty) = input.to_self() {
1146 clean::SelfValue => {
1147 args.push_str("self");
1148 args_plain.push_str("self");
1150 clean::SelfBorrowed(Some(ref lt), mtbl) => {
1151 args.push_str(&format!(
1155 mtbl.print_with_space()
1157 args_plain.push_str(&format!(
1160 mtbl.print_with_space()
1163 clean::SelfBorrowed(None, mtbl) => {
1164 args.push_str(&format!("{}{}self", amp, mtbl.print_with_space()));
1165 args_plain.push_str(&format!("&{}self", mtbl.print_with_space()));
1167 clean::SelfExplicit(ref typ) => {
1169 args.push_str(&format!("self: {:#}", typ.print(cx)));
1171 args.push_str(&format!("self: {}", typ.print(cx)));
1173 args_plain.push_str(&format!("self: {:#}", typ.print(cx)));
1178 args.push_str(" <br>");
1179 args_plain.push(' ');
1182 args.push_str("const ");
1183 args_plain.push_str("const ");
1185 if !input.name.is_empty() {
1186 args.push_str(&format!("{}: ", input.name));
1187 args_plain.push_str(&format!("{}: ", input.name));
1191 args.push_str(&format!("{:#}", input.type_.print(cx)));
1193 args.push_str(&input.type_.print(cx).to_string());
1195 args_plain.push_str(&format!("{:#}", input.type_.print(cx)));
1197 if i + 1 < self.inputs.values.len() {
1199 args_plain.push(',');
1203 let mut args_plain = format!("({})", args_plain);
1205 if self.c_variadic {
1206 args.push_str(",<br> ...");
1207 args_plain.push_str(", ...");
1211 let arrow = if let hir::IsAsync::Async = asyncness {
1212 let output = self.sugared_async_return_type();
1213 arrow_plain = format!("{:#}", output.print(cx));
1214 if f.alternate() { arrow_plain.clone() } else { format!("{}", output.print(cx)) }
1216 arrow_plain = format!("{:#}", self.output.print(cx));
1217 if f.alternate() { arrow_plain.clone() } else { format!("{}", self.output.print(cx)) }
1220 let declaration_len = header_len + args_plain.len() + arrow_plain.len();
1221 let output = if declaration_len > 80 {
1222 let full_pad = format!("<br>{}", " ".repeat(indent + 4));
1223 let close_pad = format!("<br>{}", " ".repeat(indent));
1225 "({args}{close}){arrow}",
1226 args = args.replace("<br>", &full_pad),
1231 format!("({args}){arrow}", args = args.replace("<br>", ""), arrow = arrow)
1235 write!(f, "{}", output.replace("<br>", "\n"))
1237 write!(f, "{}", output)
1242 impl clean::Visibility {
1243 crate fn print_with_space<'a, 'tcx: 'a>(
1246 cx: &'a Context<'tcx>,
1247 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1248 let to_print = match self {
1249 clean::Public => "pub ".to_owned(),
1250 clean::Inherited => String::new(),
1251 clean::Visibility::Restricted(vis_did) => {
1252 // FIXME(camelid): This may not work correctly if `item_did` is a module.
1253 // However, rustdoc currently never displays a module's
1254 // visibility, so it shouldn't matter.
1255 let parent_module = find_nearest_parent_module(cx.tcx(), item_did.expect_def_id());
1257 if vis_did.index == CRATE_DEF_INDEX {
1258 "pub(crate) ".to_owned()
1259 } else if parent_module == Some(vis_did) {
1260 // `pub(in foo)` where `foo` is the parent module
1261 // is the same as no visibility modifier
1263 } else if parent_module
1264 .map(|parent| find_nearest_parent_module(cx.tcx(), parent))
1268 "pub(super) ".to_owned()
1270 let path = cx.tcx().def_path(vis_did);
1271 debug!("path={:?}", path);
1272 // modified from `resolved_path()` to work with `DefPathData`
1273 let last_name = path.data.last().unwrap().data.get_opt_name().unwrap();
1274 let anchor = anchor(vis_did, &last_name.as_str(), cx).to_string();
1276 let mut s = "pub(in ".to_owned();
1277 for seg in &path.data[..path.data.len() - 1] {
1278 s.push_str(&format!("{}::", seg.data.get_opt_name().unwrap()));
1280 s.push_str(&format!("{}) ", anchor));
1285 display_fn(move |f| f.write_str(&to_print))
1288 /// This function is the same as print_with_space, except that it renders no links.
1289 /// It's used for macros' rendered source view, which is syntax highlighted and cannot have
1291 crate fn to_src_with_space<'a, 'tcx: 'a>(
1295 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1296 let to_print = match self {
1297 clean::Public => "pub ".to_owned(),
1298 clean::Inherited => String::new(),
1299 clean::Visibility::Restricted(vis_did) => {
1300 // FIXME(camelid): This may not work correctly if `item_did` is a module.
1301 // However, rustdoc currently never displays a module's
1302 // visibility, so it shouldn't matter.
1303 let parent_module = find_nearest_parent_module(tcx, item_did);
1305 if vis_did.index == CRATE_DEF_INDEX {
1306 "pub(crate) ".to_owned()
1307 } else if parent_module == Some(vis_did) {
1308 // `pub(in foo)` where `foo` is the parent module
1309 // is the same as no visibility modifier
1311 } else if parent_module
1312 .map(|parent| find_nearest_parent_module(tcx, parent))
1316 "pub(super) ".to_owned()
1318 format!("pub(in {}) ", tcx.def_path_str(vis_did))
1322 display_fn(move |f| f.write_str(&to_print))
1326 crate trait PrintWithSpace {
1327 fn print_with_space(&self) -> &str;
1330 impl PrintWithSpace for hir::Unsafety {
1331 fn print_with_space(&self) -> &str {
1333 hir::Unsafety::Unsafe => "unsafe ",
1334 hir::Unsafety::Normal => "",
1339 impl PrintWithSpace for hir::IsAsync {
1340 fn print_with_space(&self) -> &str {
1342 hir::IsAsync::Async => "async ",
1343 hir::IsAsync::NotAsync => "",
1348 impl PrintWithSpace for hir::Mutability {
1349 fn print_with_space(&self) -> &str {
1351 hir::Mutability::Not => "",
1352 hir::Mutability::Mut => "mut ",
1357 crate fn print_constness_with_space(c: &hir::Constness, s: Option<ConstStability>) -> &'static str {
1359 // const stable or when feature(staged_api) is not set
1361 hir::Constness::Const,
1362 Some(ConstStability { level: StabilityLevel::Stable { .. }, .. }),
1364 | (hir::Constness::Const, None) => "const ",
1365 // const unstable or not const
1370 impl clean::Import {
1371 crate fn print<'a, 'tcx: 'a>(
1373 cx: &'a Context<'tcx>,
1374 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1375 display_fn(move |f| match self.kind {
1376 clean::ImportKind::Simple(name) => {
1377 if name == self.source.path.last() {
1378 write!(f, "use {};", self.source.print(cx))
1380 write!(f, "use {} as {};", self.source.print(cx), name)
1383 clean::ImportKind::Glob => {
1384 if self.source.path.segments.is_empty() {
1387 write!(f, "use {}::*;", self.source.print(cx))
1394 impl clean::ImportSource {
1395 crate fn print<'a, 'tcx: 'a>(
1397 cx: &'a Context<'tcx>,
1398 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1399 display_fn(move |f| match self.did {
1400 Some(did) => resolved_path(f, did, &self.path, true, false, cx),
1402 for seg in &self.path.segments[..self.path.segments.len() - 1] {
1403 write!(f, "{}::", seg.name)?;
1405 let name = self.path.last_name();
1406 if let hir::def::Res::PrimTy(p) = self.path.res {
1407 primitive_link(f, PrimitiveType::from(p), &*name, cx)?;
1409 write!(f, "{}", name)?;
1417 impl clean::TypeBinding {
1418 crate fn print<'a, 'tcx: 'a>(
1420 cx: &'a Context<'tcx>,
1421 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1422 display_fn(move |f| {
1423 f.write_str(&*self.name.as_str())?;
1425 clean::TypeBindingKind::Equality { ref ty } => {
1427 write!(f, " = {:#}", ty.print(cx))?;
1429 write!(f, " = {}", ty.print(cx))?;
1432 clean::TypeBindingKind::Constraint { ref bounds } => {
1433 if !bounds.is_empty() {
1435 write!(f, ": {:#}", print_generic_bounds(bounds, cx))?;
1437 write!(f, ": {}", print_generic_bounds(bounds, cx))?;
1447 crate fn print_abi_with_space(abi: Abi) -> impl fmt::Display {
1448 display_fn(move |f| {
1449 let quot = if f.alternate() { "\"" } else { """ };
1451 Abi::Rust => Ok(()),
1452 abi => write!(f, "extern {0}{1}{0} ", quot, abi.name()),
1457 crate fn print_default_space<'a>(v: bool) -> &'a str {
1458 if v { "default " } else { "" }
1461 impl clean::GenericArg {
1462 crate fn print<'a, 'tcx: 'a>(
1464 cx: &'a Context<'tcx>,
1465 ) -> impl fmt::Display + 'a + Captures<'tcx> {
1466 display_fn(move |f| match self {
1467 clean::GenericArg::Lifetime(lt) => fmt::Display::fmt(<.print(), f),
1468 clean::GenericArg::Type(ty) => fmt::Display::fmt(&ty.print(cx), f),
1469 clean::GenericArg::Const(ct) => fmt::Display::fmt(&ct.print(cx.tcx()), f),
1470 clean::GenericArg::Infer => fmt::Display::fmt("_", f),
1475 crate fn display_fn(f: impl FnOnce(&mut fmt::Formatter<'_>) -> fmt::Result) -> impl fmt::Display {
1476 struct WithFormatter<F>(Cell<Option<F>>);
1478 impl<F> fmt::Display for WithFormatter<F>
1480 F: FnOnce(&mut fmt::Formatter<'_>) -> fmt::Result,
1482 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1483 (self.0.take()).unwrap()(f)
1487 WithFormatter(Cell::new(Some(f)))