1 use std::iter::ExactSizeIterator;
4 use rustc_ast::ast::{self, FnRetTy, Mutability};
5 use rustc_span::{symbol::kw, BytePos, Pos, Span};
7 use crate::comment::{combine_strs_with_missing_comments, contains_comment};
8 use crate::config::lists::*;
9 use crate::config::{IndentStyle, TypeDensity, Version};
11 format_expr, rewrite_assign_rhs, rewrite_call, rewrite_tuple, rewrite_unary_prefix, ExprType,
14 definitive_tactic, itemize_list, write_list, ListFormatting, ListItem, Separator,
16 use crate::macros::{rewrite_macro, MacroPosition};
18 use crate::pairs::{rewrite_pair, PairParts};
19 use crate::rewrite::{Rewrite, RewriteContext};
20 use crate::shape::Shape;
21 use crate::source_map::SpanUtils;
22 use crate::spanned::Spanned;
24 colon_spaces, extra_offset, first_line_width, format_extern, format_mutability,
25 last_line_extendable, last_line_width, mk_sp, rewrite_ident,
28 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
29 pub(crate) enum PathContext {
35 // Does not wrap on simple segments.
36 pub(crate) fn rewrite_path(
37 context: &RewriteContext<'_>,
38 path_context: PathContext,
39 qself: Option<&ast::QSelf>,
43 let skip_count = qself.map_or(0, |x| x.position);
45 let mut result = if path.is_global() && qself.is_none() && path_context != PathContext::Import {
51 let mut span_lo = path.span.lo();
53 if let Some(qself) = qself {
56 let fmt_ty = qself.ty.rewrite(context, shape)?;
57 result.push_str(&fmt_ty);
60 result.push_str(" as ");
61 if path.is_global() && path_context != PathContext::Import {
62 result.push_str("::");
66 let shape = shape.sub_width(3)?;
68 result = rewrite_path_segments(
71 path.segments.iter().take(skip_count),
79 result.push_str(">::");
80 span_lo = qself.ty.span.hi() + BytePos(1);
83 rewrite_path_segments(
86 path.segments.iter().skip(skip_count),
94 fn rewrite_path_segments<'a, I>(
95 path_context: PathContext,
100 context: &RewriteContext<'_>,
104 I: Iterator<Item = &'a ast::PathSegment>,
106 let mut first = true;
107 let shape = shape.visual_indent(0);
109 for segment in iter {
110 // Indicates a global path, shouldn't be rendered.
111 if segment.ident.name == kw::PathRoot {
117 buffer.push_str("::");
120 let extra_offset = extra_offset(&buffer, shape);
121 let new_shape = shape.shrink_left(extra_offset)?;
122 let segment_string = rewrite_segment(
131 buffer.push_str(&segment_string);
138 pub(crate) enum SegmentParam<'a> {
139 Const(&'a ast::AnonConst),
140 LifeTime(&'a ast::Lifetime),
142 Binding(&'a ast::AssocTyConstraint),
145 impl<'a> SegmentParam<'a> {
146 fn from_generic_arg(arg: &ast::GenericArg) -> SegmentParam<'_> {
148 ast::GenericArg::Lifetime(ref lt) => SegmentParam::LifeTime(lt),
149 ast::GenericArg::Type(ref ty) => SegmentParam::Type(ty),
150 ast::GenericArg::Const(const_) => SegmentParam::Const(const_),
155 impl<'a> Spanned for SegmentParam<'a> {
156 fn span(&self) -> Span {
158 SegmentParam::Const(const_) => const_.value.span,
159 SegmentParam::LifeTime(lt) => lt.ident.span,
160 SegmentParam::Type(ty) => ty.span,
161 SegmentParam::Binding(binding) => binding.span,
166 impl<'a> Rewrite for SegmentParam<'a> {
167 fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> {
169 SegmentParam::Const(const_) => const_.rewrite(context, shape),
170 SegmentParam::LifeTime(lt) => lt.rewrite(context, shape),
171 SegmentParam::Type(ty) => ty.rewrite(context, shape),
172 SegmentParam::Binding(assoc_ty_constraint) => {
173 let mut result = match assoc_ty_constraint.kind {
174 ast::AssocTyConstraintKind::Bound { .. } => {
175 format!("{}: ", rewrite_ident(context, assoc_ty_constraint.ident))
177 ast::AssocTyConstraintKind::Equality { .. } => {
178 match context.config.type_punctuation_density() {
179 TypeDensity::Wide => {
180 format!("{} = ", rewrite_ident(context, assoc_ty_constraint.ident))
182 TypeDensity::Compressed => {
183 format!("{}=", rewrite_ident(context, assoc_ty_constraint.ident))
189 let budget = shape.width.checked_sub(result.len())?;
190 let rewrite = assoc_ty_constraint
192 .rewrite(context, Shape::legacy(budget, shape.indent + result.len()))?;
193 result.push_str(&rewrite);
200 impl Rewrite for ast::AssocTyConstraintKind {
201 fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> {
203 ast::AssocTyConstraintKind::Equality { ty } => ty.rewrite(context, shape),
204 ast::AssocTyConstraintKind::Bound { bounds } => bounds.rewrite(context, shape),
209 // Formats a path segment. There are some hacks involved to correctly determine
210 // the segment's associated span since it's not part of the AST.
212 // The span_lo is assumed to be greater than the end of any previous segment's
213 // parameters and lesser or equal than the start of current segment.
215 // span_hi is assumed equal to the end of the entire path.
217 // When the segment contains a positive number of parameters, we update span_lo
218 // so that invariants described above will hold for the next segment.
220 path_context: PathContext,
221 segment: &ast::PathSegment,
222 span_lo: &mut BytePos,
224 context: &RewriteContext<'_>,
226 ) -> Option<String> {
227 let mut result = String::with_capacity(128);
228 result.push_str(rewrite_ident(context, segment.ident));
230 let ident_len = result.len();
231 let shape = if context.use_block_indent() {
232 shape.offset_left(ident_len)?
234 shape.shrink_left(ident_len)?
237 if let Some(ref args) = segment.args {
239 ast::GenericArgs::AngleBracketed(ref data) if !data.args.is_empty() => {
240 let param_list = data
244 ast::AngleBracketedArg::Arg(generic_arg) => {
245 SegmentParam::from_generic_arg(generic_arg)
247 ast::AngleBracketedArg::Constraint(constraint) => {
248 SegmentParam::Binding(constraint)
251 .collect::<Vec<_>>();
253 // HACK: squeeze out the span between the identifier and the parameters.
254 // The hack is requried so that we don't remove the separator inside macro calls.
255 // This does not work in the presence of comment, hoping that people are
256 // sane about where to put their comment.
257 let separator_snippet = context
258 .snippet(mk_sp(segment.ident.span.hi(), data.span.lo()))
260 let force_separator = context.inside_macro() && separator_snippet.starts_with("::");
261 let separator = if path_context == PathContext::Expr || force_separator {
266 result.push_str(separator);
268 let generics_str = overflow::rewrite_with_angle_brackets(
273 mk_sp(*span_lo, span_hi),
276 // Update position of last bracket.
279 .span_after(mk_sp(*span_lo, span_hi), "<");
281 result.push_str(&generics_str)
283 ast::GenericArgs::Parenthesized(ref data) => {
284 result.push_str(&format_function_type(
285 data.inputs.iter().map(|x| &**x),
300 fn format_function_type<'a, I>(
305 context: &RewriteContext<'_>,
309 I: ExactSizeIterator,
310 <I as Iterator>::Item: Deref,
311 <I::Item as Deref>::Target: Rewrite + Spanned + 'a,
313 debug!("format_function_type {:#?}", shape);
315 let ty_shape = match context.config.indent_style() {
317 IndentStyle::Block => shape.offset_left(4)?,
318 IndentStyle::Visual => shape.block_left(4)?,
320 let output = match *output {
321 FnRetTy::Ty(ref ty) => {
322 let type_str = ty.rewrite(context, ty_shape)?;
323 format!(" -> {}", type_str)
325 FnRetTy::Default(..) => String::new(),
328 let list_shape = if context.use_block_indent() {
330 shape.block().indent.block_indent(context.config),
335 let budget = shape.width.checked_sub(2)?;
337 let offset = shape.indent + 1;
338 Shape::legacy(budget, offset)
341 let is_inputs_empty = inputs.len() == 0;
342 let list_lo = context.snippet_provider.span_after(span, "(");
343 let (list_str, tactic) = if is_inputs_empty {
344 let tactic = get_tactics(&[], &output, shape);
345 let list_hi = context.snippet_provider.span_before(span, ")");
346 let comment = context
348 .span_to_snippet(mk_sp(list_lo, list_hi))?
350 let comment = if comment.starts_with("//") {
353 &list_shape.indent.to_string_with_newline(context.config),
355 &shape.block().indent.to_string_with_newline(context.config)
362 let items = itemize_list(
363 context.snippet_provider,
367 |arg| arg.span().lo(),
368 |arg| arg.span().hi(),
369 |arg| arg.rewrite(context, list_shape),
375 let item_vec: Vec<_> = items.collect();
376 let tactic = get_tactics(&item_vec, &output, shape);
377 let trailing_separator = if !context.use_block_indent() || variadic {
378 SeparatorTactic::Never
380 context.config.trailing_comma()
383 let fmt = ListFormatting::new(list_shape, context.config)
385 .trailing_separator(trailing_separator)
386 .ends_with_newline(tactic.ends_with_newline(context.config.indent_style()))
387 .preserve_newline(true);
388 (write_list(&item_vec, &fmt)?, tactic)
391 let args = if tactic == DefinitiveListTactic::Horizontal
392 || !context.use_block_indent()
395 format!("({})", list_str)
399 list_shape.indent.to_string_with_newline(context.config),
401 shape.block().indent.to_string_with_newline(context.config),
404 if output.is_empty() || last_line_width(&args) + first_line_width(&output) <= shape.width {
405 Some(format!("{}{}", args, output))
410 list_shape.indent.to_string(context.config),
416 fn type_bound_colon(context: &RewriteContext<'_>) -> &'static str {
417 colon_spaces(context.config)
420 // If the return type is multi-lined, then force to use multiple lines for
421 // arguments as well.
422 fn get_tactics(item_vec: &[ListItem], output: &str, shape: Shape) -> DefinitiveListTactic {
423 if output.contains('\n') {
424 DefinitiveListTactic::Vertical
428 ListTactic::HorizontalVertical,
430 // 2 is for the case of ',\n'
431 shape.width.saturating_sub(2 + output.len()),
436 impl Rewrite for ast::WherePredicate {
437 fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> {
438 // FIXME: dead spans?
439 let result = match *self {
440 ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate {
441 ref bound_generic_params,
446 let type_str = bounded_ty.rewrite(context, shape)?;
447 let colon = type_bound_colon(context).trim_end();
448 let lhs = if let Some(lifetime_str) =
449 rewrite_lifetime_param(context, shape, bound_generic_params)
451 format!("for<{}> {}{}", lifetime_str, type_str, colon)
453 format!("{}{}", type_str, colon)
456 rewrite_assign_rhs(context, lhs, bounds, shape)?
458 ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate {
462 }) => rewrite_bounded_lifetime(lifetime, bounds, context, shape)?,
463 ast::WherePredicate::EqPredicate(ast::WhereEqPredicate {
468 let lhs_ty_str = lhs_ty.rewrite(context, shape).map(|lhs| lhs + " =")?;
469 rewrite_assign_rhs(context, lhs_ty_str, &**rhs_ty, shape)?
477 impl Rewrite for ast::GenericArg {
478 fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> {
480 ast::GenericArg::Lifetime(ref lt) => lt.rewrite(context, shape),
481 ast::GenericArg::Type(ref ty) => ty.rewrite(context, shape),
482 ast::GenericArg::Const(ref const_) => const_.rewrite(context, shape),
487 fn rewrite_bounded_lifetime(
489 bounds: &[ast::GenericBound],
490 context: &RewriteContext<'_>,
492 ) -> Option<String> {
493 let result = lt.rewrite(context, shape)?;
495 if bounds.is_empty() {
498 let colon = type_bound_colon(context);
499 let overhead = last_line_width(&result) + colon.len();
500 let result = format!(
504 join_bounds(context, shape.sub_width(overhead)?, bounds, true)?
510 impl Rewrite for ast::AnonConst {
511 fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> {
512 format_expr(&self.value, ExprType::SubExpression, context, shape)
516 impl Rewrite for ast::Lifetime {
517 fn rewrite(&self, context: &RewriteContext<'_>, _: Shape) -> Option<String> {
518 Some(rewrite_ident(context, self.ident).to_owned())
522 impl Rewrite for ast::GenericBound {
523 fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> {
525 ast::GenericBound::Trait(ref poly_trait_ref, trait_bound_modifier) => {
526 let snippet = context.snippet(self.span());
527 let has_paren = snippet.starts_with('(') && snippet.ends_with(')');
528 let rewrite = match trait_bound_modifier {
529 ast::TraitBoundModifier::None => poly_trait_ref.rewrite(context, shape),
530 ast::TraitBoundModifier::Maybe => poly_trait_ref
531 .rewrite(context, shape.offset_left(1)?)
532 .map(|s| format!("?{}", s)),
533 ast::TraitBoundModifier::MaybeConst => poly_trait_ref
534 .rewrite(context, shape.offset_left(7)?)
535 .map(|s| format!("~const {}", s)),
536 ast::TraitBoundModifier::MaybeConstMaybe => poly_trait_ref
537 .rewrite(context, shape.offset_left(8)?)
538 .map(|s| format!("~const ?{}", s)),
540 rewrite.map(|s| if has_paren { format!("({})", s) } else { s })
542 ast::GenericBound::Outlives(ref lifetime) => lifetime.rewrite(context, shape),
547 impl Rewrite for ast::GenericBounds {
548 fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> {
550 return Some(String::new());
553 join_bounds(context, shape, self, true)
557 impl Rewrite for ast::GenericParam {
558 fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> {
559 let mut result = String::with_capacity(128);
560 // FIXME: If there are more than one attributes, this will force multiline.
561 match self.attrs.rewrite(context, shape) {
562 Some(ref rw) if !rw.is_empty() => result.push_str(&format!("{} ", rw)),
566 if let ast::GenericParamKind::Const {
572 result.push_str("const ");
573 result.push_str(rewrite_ident(context, self.ident));
574 result.push_str(": ");
575 result.push_str(&ty.rewrite(context, shape)?);
577 result.push_str(rewrite_ident(context, self.ident));
580 if !self.bounds.is_empty() {
581 result.push_str(type_bound_colon(context));
582 result.push_str(&self.bounds.rewrite(context, shape)?)
584 if let ast::GenericParamKind::Type {
585 default: Some(ref def),
588 let eq_str = match context.config.type_punctuation_density() {
589 TypeDensity::Compressed => "=",
590 TypeDensity::Wide => " = ",
592 result.push_str(eq_str);
593 let budget = shape.width.checked_sub(result.len())?;
595 def.rewrite(context, Shape::legacy(budget, shape.indent + result.len()))?;
596 result.push_str(&rewrite);
603 impl Rewrite for ast::PolyTraitRef {
604 fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> {
605 if let Some(lifetime_str) =
606 rewrite_lifetime_param(context, shape, &self.bound_generic_params)
608 // 6 is "for<> ".len()
609 let extra_offset = lifetime_str.len() + 6;
612 .rewrite(context, shape.offset_left(extra_offset)?)?;
614 Some(format!("for<{}> {}", lifetime_str, path_str))
616 self.trait_ref.rewrite(context, shape)
621 impl Rewrite for ast::TraitRef {
622 fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> {
623 rewrite_path(context, PathContext::Type, None, &self.path, shape)
627 impl Rewrite for ast::Ty {
628 fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> {
630 ast::TyKind::TraitObject(ref bounds, tobj_syntax) => {
631 // we have to consider 'dyn' keyword is used or not!!!
632 let is_dyn = tobj_syntax == ast::TraitObjectSyntax::Dyn;
633 // 4 is length of 'dyn '
634 let shape = if is_dyn { shape.offset_left(4)? } else { shape };
635 let mut res = bounds.rewrite(context, shape)?;
636 // We may have falsely removed a trailing `+` inside macro call.
637 if context.inside_macro() && bounds.len() == 1 {
638 if context.snippet(self.span).ends_with('+') && !res.ends_with('+') {
643 Some(format!("dyn {}", res))
648 ast::TyKind::Ptr(ref mt) => {
649 let prefix = match mt.mutbl {
650 Mutability::Mut => "*mut ",
651 Mutability::Not => "*const ",
654 rewrite_unary_prefix(context, prefix, &*mt.ty, shape)
656 ast::TyKind::Rptr(ref lifetime, ref mt) => {
657 let mut_str = format_mutability(mt.mutbl);
658 let mut_len = mut_str.len();
659 let mut result = String::with_capacity(128);
661 let ref_hi = context.snippet_provider.span_after(self.span(), "&");
662 let mut cmnt_lo = ref_hi;
664 if let Some(ref lifetime) = *lifetime {
665 let lt_budget = shape.width.checked_sub(2 + mut_len)?;
666 let lt_str = lifetime.rewrite(
668 Shape::legacy(lt_budget, shape.indent + 2 + mut_len),
670 let before_lt_span = mk_sp(cmnt_lo, lifetime.ident.span.lo());
671 if contains_comment(context.snippet(before_lt_span)) {
672 result = combine_strs_with_missing_comments(
681 result.push_str(<_str);
684 cmnt_lo = lifetime.ident.span.hi();
687 if ast::Mutability::Mut == mt.mutbl {
688 let mut_hi = context.snippet_provider.span_after(self.span(), "mut");
689 let before_mut_span = mk_sp(cmnt_lo, mut_hi - BytePos::from_usize(3));
690 if contains_comment(context.snippet(before_mut_span)) {
691 result = combine_strs_with_missing_comments(
700 result.push_str(mut_str);
705 let before_ty_span = mk_sp(cmnt_lo, mt.ty.span.lo());
706 if contains_comment(context.snippet(before_ty_span)) {
707 result = combine_strs_with_missing_comments(
710 &mt.ty.rewrite(&context, shape)?,
716 let used_width = last_line_width(&result);
717 let budget = shape.width.checked_sub(used_width)?;
720 .rewrite(&context, Shape::legacy(budget, shape.indent + used_width))?;
721 result.push_str(&ty_str);
726 // FIXME: we drop any comments here, even though it's a silly place to put
728 ast::TyKind::Paren(ref ty) => {
729 if context.config.version() == Version::One
730 || context.config.indent_style() == IndentStyle::Visual
732 let budget = shape.width.checked_sub(2)?;
734 .rewrite(context, Shape::legacy(budget, shape.indent + 1))
735 .map(|ty_str| format!("({})", ty_str));
739 if let Some(sh) = shape.sub_width(2) {
740 if let Some(ref s) = ty.rewrite(context, sh) {
741 if !s.contains('\n') {
742 return Some(format!("({})", s));
747 let indent_str = shape.indent.to_string_with_newline(context.config);
749 .block_indent(context.config.tab_spaces())
750 .with_max_width(context.config);
751 let rw = ty.rewrite(context, shape)?;
754 shape.to_string_with_newline(context.config),
759 ast::TyKind::Slice(ref ty) => {
760 let budget = shape.width.checked_sub(4)?;
761 ty.rewrite(context, Shape::legacy(budget, shape.indent + 1))
762 .map(|ty_str| format!("[{}]", ty_str))
764 ast::TyKind::Tup(ref items) => {
765 rewrite_tuple(context, items.iter(), self.span, shape, items.len() == 1)
767 ast::TyKind::Path(ref q_self, ref path) => {
768 rewrite_path(context, PathContext::Type, q_self.as_ref(), path, shape)
770 ast::TyKind::Array(ref ty, ref repeats) => rewrite_pair(
773 PairParts::new("[", "; ", "]"),
776 SeparatorPlace::Back,
778 ast::TyKind::Infer => {
779 if shape.width >= 1 {
785 ast::TyKind::BareFn(ref bare_fn) => rewrite_bare_fn(bare_fn, self.span, context, shape),
786 ast::TyKind::Never => Some(String::from("!")),
787 ast::TyKind::MacCall(ref mac) => {
788 rewrite_macro(mac, None, context, shape, MacroPosition::Expression)
790 ast::TyKind::ImplicitSelf => Some(String::from("")),
791 ast::TyKind::ImplTrait(_, ref it) => {
792 // Empty trait is not a parser error.
794 return Some("impl".to_owned());
796 let rw = if context.config.version() == Version::One {
797 it.rewrite(context, shape)
799 join_bounds(context, shape, it, false)
802 let space = if it_str.is_empty() { "" } else { " " };
803 format!("impl{}{}", space, it_str)
806 ast::TyKind::CVarArgs => Some("...".to_owned()),
807 ast::TyKind::Err => Some(context.snippet(self.span).to_owned()),
808 ast::TyKind::Typeof(ref anon_const) => rewrite_call(
811 &[anon_const.value.clone()],
820 bare_fn: &ast::BareFnTy,
822 context: &RewriteContext<'_>,
824 ) -> Option<String> {
825 debug!("rewrite_bare_fn {:#?}", shape);
827 let mut result = String::with_capacity(128);
829 if let Some(ref lifetime_str) = rewrite_lifetime_param(context, shape, &bare_fn.generic_params)
831 result.push_str("for<");
832 // 6 = "for<> ".len(), 4 = "for<".
833 // This doesn't work out so nicely for multiline situation with lots of
834 // rightward drift. If that is a problem, we could use the list stuff.
835 result.push_str(lifetime_str);
836 result.push_str("> ");
839 result.push_str(crate::utils::format_unsafety(bare_fn.unsafety));
841 result.push_str(&format_extern(
843 context.config.force_explicit_abi(),
847 result.push_str("fn");
849 let func_ty_shape = if context.use_block_indent() {
850 shape.offset_left(result.len())?
852 shape.visual_indent(result.len()).sub_width(result.len())?
855 let rewrite = format_function_type(
856 bare_fn.decl.inputs.iter(),
857 &bare_fn.decl.output,
858 bare_fn.decl.c_variadic(),
864 result.push_str(&rewrite);
869 fn is_generic_bounds_in_order(generic_bounds: &[ast::GenericBound]) -> bool {
870 let is_trait = |b: &ast::GenericBound| match b {
871 ast::GenericBound::Outlives(..) => false,
872 ast::GenericBound::Trait(..) => true,
874 let is_lifetime = |b: &ast::GenericBound| !is_trait(b);
875 let last_trait_index = generic_bounds.iter().rposition(is_trait);
876 let first_lifetime_index = generic_bounds.iter().position(is_lifetime);
877 match (last_trait_index, first_lifetime_index) {
878 (Some(last_trait_index), Some(first_lifetime_index)) => {
879 last_trait_index < first_lifetime_index
886 context: &RewriteContext<'_>,
888 items: &[ast::GenericBound],
890 ) -> Option<String> {
891 join_bounds_inner(context, shape, items, need_indent, false)
894 fn join_bounds_inner(
895 context: &RewriteContext<'_>,
897 items: &[ast::GenericBound],
900 ) -> Option<String> {
901 debug_assert!(!items.is_empty());
903 let generic_bounds_in_order = is_generic_bounds_in_order(items);
904 let is_bound_extendable = |s: &str, b: &ast::GenericBound| match b {
905 ast::GenericBound::Outlives(..) => true,
906 ast::GenericBound::Trait(..) => last_line_extendable(s),
909 let result = items.iter().enumerate().try_fold(
910 (String::new(), None, false),
911 |(strs, prev_trailing_span, prev_extendable), (i, item)| {
912 let trailing_span = if i < items.len() - 1 {
915 .span_before(mk_sp(items[i + 1].span().lo(), item.span().hi()), "+");
917 Some(mk_sp(item.span().hi(), hi))
921 let (leading_span, has_leading_comment) = if i > 0 {
924 .span_after(mk_sp(items[i - 1].span().hi(), item.span().lo()), "+");
926 let span = mk_sp(lo, item.span().lo());
928 let has_comments = contains_comment(context.snippet(span));
930 (Some(mk_sp(lo, item.span().lo())), has_comments)
934 let prev_has_trailing_comment = match prev_trailing_span {
935 Some(ts) => contains_comment(context.snippet(ts)),
939 let shape = if need_indent && force_newline {
941 .block_indent(context.config.tab_spaces())
942 .with_max_width(context.config)
946 let whitespace = if force_newline && (!prev_extendable || !generic_bounds_in_order) {
949 .to_string_with_newline(context.config)
955 let joiner = match context.config.type_punctuation_density() {
956 TypeDensity::Compressed => String::from("+"),
957 TypeDensity::Wide => whitespace + "+ ",
959 let joiner = if has_leading_comment {
964 let joiner = if prev_has_trailing_comment {
970 let (extendable, trailing_str) = if i == 0 {
971 let bound_str = item.rewrite(context, shape)?;
972 (is_bound_extendable(&bound_str, item), bound_str)
974 let bound_str = &item.rewrite(context, shape)?;
976 Some(ls) if has_leading_comment => (
977 is_bound_extendable(bound_str, item),
978 combine_strs_with_missing_comments(
979 context, joiner, bound_str, ls, shape, true,
983 is_bound_extendable(bound_str, item),
984 String::from(joiner) + bound_str,
988 match prev_trailing_span {
989 Some(ts) if prev_has_trailing_comment => combine_strs_with_missing_comments(
997 .map(|v| (v, trailing_span, extendable)),
998 _ => Some((strs + &trailing_str, trailing_span, extendable)),
1005 && (result.0.contains('\n') || result.0.len() > shape.width)
1007 join_bounds_inner(context, shape, items, need_indent, true)
1013 pub(crate) fn can_be_overflowed_type(
1014 context: &RewriteContext<'_>,
1019 ast::TyKind::Tup(..) => context.use_block_indent() && len == 1,
1020 ast::TyKind::Rptr(_, ref mutty) | ast::TyKind::Ptr(ref mutty) => {
1021 can_be_overflowed_type(context, &*mutty.ty, len)
1027 /// Returns `None` if there is no `LifetimeDef` in the given generic parameters.
1028 fn rewrite_lifetime_param(
1029 context: &RewriteContext<'_>,
1031 generic_params: &[ast::GenericParam],
1032 ) -> Option<String> {
1033 let result = generic_params
1035 .filter(|p| matches!(p.kind, ast::GenericParamKind::Lifetime))
1036 .map(|lt| lt.rewrite(context, shape))
1037 .collect::<Option<Vec<_>>>()?
1039 if result.is_empty() {