| use rustc_ast::ast::{ |
| self, BindingAnnotation, ByRef, Pat, PatField, PatKind, RangeEnd, RangeSyntax, |
| }; |
| use rustc_ast::ptr; |
| use rustc_span::{BytePos, Span}; |
| |
| use crate::comment::{combine_strs_with_missing_comments, FindUncommented}; |
| use crate::config::lists::*; |
| use crate::config::Version; |
| use crate::expr::{can_be_overflowed_expr, rewrite_unary_prefix, wrap_struct_field}; |
| use crate::lists::{ |
| definitive_tactic, itemize_list, shape_for_tactic, struct_lit_formatting, struct_lit_shape, |
| struct_lit_tactic, write_list, ListFormatting, ListItem, Separator, |
| }; |
| use crate::macros::{rewrite_macro, MacroPosition}; |
| use crate::overflow; |
| use crate::pairs::{rewrite_pair, PairParts}; |
| use crate::rewrite::{Rewrite, RewriteContext}; |
| use crate::shape::Shape; |
| use crate::source_map::SpanUtils; |
| use crate::spanned::Spanned; |
| use crate::types::{rewrite_path, PathContext}; |
| use crate::utils::{format_mutability, mk_sp, mk_sp_lo_plus_one, rewrite_ident}; |
| |
| /// Returns `true` if the given pattern is "short". |
| /// A short pattern is defined by the following grammar: |
| /// |
| /// `[small, ntp]`: |
| /// - single token |
| /// - `&[single-line, ntp]` |
| /// |
| /// `[small]`: |
| /// - `[small, ntp]` |
| /// - unary tuple constructor `([small, ntp])` |
| /// - `&[small]` |
| pub(crate) fn is_short_pattern(pat: &ast::Pat, pat_str: &str) -> bool { |
| // We also require that the pattern is reasonably 'small' with its literal width. |
| pat_str.len() <= 20 && !pat_str.contains('\n') && is_short_pattern_inner(pat) |
| } |
| |
| fn is_short_pattern_inner(pat: &ast::Pat) -> bool { |
| match pat.kind { |
| ast::PatKind::Rest | ast::PatKind::Wild | ast::PatKind::Lit(_) => true, |
| ast::PatKind::Ident(_, _, ref pat) => pat.is_none(), |
| ast::PatKind::Struct(..) |
| | ast::PatKind::MacCall(..) |
| | ast::PatKind::Slice(..) |
| | ast::PatKind::Path(..) |
| | ast::PatKind::Range(..) => false, |
| ast::PatKind::Tuple(ref subpats) => subpats.len() <= 1, |
| ast::PatKind::TupleStruct(_, ref path, ref subpats) => { |
| path.segments.len() <= 1 && subpats.len() <= 1 |
| } |
| ast::PatKind::Box(ref p) | ast::PatKind::Ref(ref p, _) | ast::PatKind::Paren(ref p) => { |
| is_short_pattern_inner(&*p) |
| } |
| PatKind::Or(ref pats) => pats.iter().all(|p| is_short_pattern_inner(p)), |
| } |
| } |
| |
| struct RangeOperand<'a>(&'a Option<ptr::P<ast::Expr>>); |
| |
| impl<'a> Rewrite for RangeOperand<'a> { |
| fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> { |
| match &self.0 { |
| None => Some("".to_owned()), |
| Some(ref exp) => exp.rewrite(context, shape), |
| } |
| } |
| } |
| |
| impl Rewrite for Pat { |
| fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> { |
| match self.kind { |
| PatKind::Or(ref pats) => { |
| let pat_strs = pats |
| .iter() |
| .map(|p| p.rewrite(context, shape)) |
| .collect::<Option<Vec<_>>>()?; |
| |
| let use_mixed_layout = pats |
| .iter() |
| .zip(pat_strs.iter()) |
| .all(|(pat, pat_str)| is_short_pattern(pat, pat_str)); |
| let items: Vec<_> = pat_strs.into_iter().map(ListItem::from_str).collect(); |
| let tactic = if use_mixed_layout { |
| DefinitiveListTactic::Mixed |
| } else { |
| definitive_tactic( |
| &items, |
| ListTactic::HorizontalVertical, |
| Separator::VerticalBar, |
| shape.width, |
| ) |
| }; |
| let fmt = ListFormatting::new(shape, context.config) |
| .tactic(tactic) |
| .separator(" |") |
| .separator_place(context.config.binop_separator()) |
| .ends_with_newline(false); |
| write_list(&items, &fmt) |
| } |
| PatKind::Box(ref pat) => rewrite_unary_prefix(context, "box ", &**pat, shape), |
| PatKind::Ident(BindingAnnotation(by_ref, mutability), ident, ref sub_pat) => { |
| let prefix = match by_ref { |
| ByRef::Yes => "ref", |
| ByRef::No => "", |
| }; |
| let mut_infix = format_mutability(mutability).trim(); |
| let id_str = rewrite_ident(context, ident); |
| let sub_pat = match *sub_pat { |
| Some(ref p) => { |
| // 2 - `@ `. |
| let width = shape |
| .width |
| .checked_sub(prefix.len() + mut_infix.len() + id_str.len() + 2)?; |
| let lo = context.snippet_provider.span_after(self.span, "@"); |
| combine_strs_with_missing_comments( |
| context, |
| "@", |
| &p.rewrite(context, Shape::legacy(width, shape.indent))?, |
| mk_sp(lo, p.span.lo()), |
| shape, |
| true, |
| )? |
| } |
| None => "".to_owned(), |
| }; |
| |
| // combine prefix and mut |
| let (first_lo, first) = if !prefix.is_empty() && !mut_infix.is_empty() { |
| let hi = context.snippet_provider.span_before(self.span, "mut"); |
| let lo = context.snippet_provider.span_after(self.span, "ref"); |
| ( |
| context.snippet_provider.span_after(self.span, "mut"), |
| combine_strs_with_missing_comments( |
| context, |
| prefix, |
| mut_infix, |
| mk_sp(lo, hi), |
| shape, |
| true, |
| )?, |
| ) |
| } else if !prefix.is_empty() { |
| ( |
| context.snippet_provider.span_after(self.span, "ref"), |
| prefix.to_owned(), |
| ) |
| } else if !mut_infix.is_empty() { |
| ( |
| context.snippet_provider.span_after(self.span, "mut"), |
| mut_infix.to_owned(), |
| ) |
| } else { |
| (self.span.lo(), "".to_owned()) |
| }; |
| |
| let next = if !sub_pat.is_empty() { |
| let hi = context.snippet_provider.span_before(self.span, "@"); |
| combine_strs_with_missing_comments( |
| context, |
| id_str, |
| &sub_pat, |
| mk_sp(ident.span.hi(), hi), |
| shape, |
| true, |
| )? |
| } else { |
| id_str.to_owned() |
| }; |
| |
| combine_strs_with_missing_comments( |
| context, |
| &first, |
| &next, |
| mk_sp(first_lo, ident.span.lo()), |
| shape, |
| true, |
| ) |
| } |
| PatKind::Wild => { |
| if 1 <= shape.width { |
| Some("_".to_owned()) |
| } else { |
| None |
| } |
| } |
| PatKind::Rest => { |
| if 1 <= shape.width { |
| Some("..".to_owned()) |
| } else { |
| None |
| } |
| } |
| PatKind::Range(ref lhs, ref rhs, ref end_kind) => { |
| let infix = match end_kind.node { |
| RangeEnd::Included(RangeSyntax::DotDotDot) => "...", |
| RangeEnd::Included(RangeSyntax::DotDotEq) => "..=", |
| RangeEnd::Excluded => "..", |
| }; |
| let infix = if context.config.spaces_around_ranges() { |
| let lhs_spacing = match lhs { |
| None => "", |
| Some(_) => " ", |
| }; |
| let rhs_spacing = match rhs { |
| None => "", |
| Some(_) => " ", |
| }; |
| format!("{lhs_spacing}{infix}{rhs_spacing}") |
| } else { |
| infix.to_owned() |
| }; |
| rewrite_pair( |
| &RangeOperand(lhs), |
| &RangeOperand(rhs), |
| PairParts::infix(&infix), |
| context, |
| shape, |
| SeparatorPlace::Front, |
| ) |
| } |
| PatKind::Ref(ref pat, mutability) => { |
| let prefix = format!("&{}", format_mutability(mutability)); |
| rewrite_unary_prefix(context, &prefix, &**pat, shape) |
| } |
| PatKind::Tuple(ref items) => rewrite_tuple_pat(items, None, self.span, context, shape), |
| PatKind::Path(ref q_self, ref path) => { |
| rewrite_path(context, PathContext::Expr, q_self, path, shape) |
| } |
| PatKind::TupleStruct(ref q_self, ref path, ref pat_vec) => { |
| let path_str = rewrite_path(context, PathContext::Expr, q_self, path, shape)?; |
| rewrite_tuple_pat(pat_vec, Some(path_str), self.span, context, shape) |
| } |
| PatKind::Lit(ref expr) => expr.rewrite(context, shape), |
| PatKind::Slice(ref slice_pat) if context.config.version() == Version::One => { |
| let rw: Vec<String> = slice_pat |
| .iter() |
| .map(|p| { |
| if let Some(rw) = p.rewrite(context, shape) { |
| rw |
| } else { |
| context.snippet(p.span).to_string() |
| } |
| }) |
| .collect(); |
| Some(format!("[{}]", rw.join(", "))) |
| } |
| PatKind::Slice(ref slice_pat) => overflow::rewrite_with_square_brackets( |
| context, |
| "", |
| slice_pat.iter(), |
| shape, |
| self.span, |
| None, |
| None, |
| ), |
| PatKind::Struct(ref qself, ref path, ref fields, ellipsis) => { |
| rewrite_struct_pat(qself, path, fields, ellipsis, self.span, context, shape) |
| } |
| PatKind::MacCall(ref mac) => { |
| rewrite_macro(mac, None, context, shape, MacroPosition::Pat) |
| } |
| PatKind::Paren(ref pat) => pat |
| .rewrite(context, shape.offset_left(1)?.sub_width(1)?) |
| .map(|inner_pat| format!("({})", inner_pat)), |
| } |
| } |
| } |
| |
| fn rewrite_struct_pat( |
| qself: &Option<ptr::P<ast::QSelf>>, |
| path: &ast::Path, |
| fields: &[ast::PatField], |
| ellipsis: bool, |
| span: Span, |
| context: &RewriteContext<'_>, |
| shape: Shape, |
| ) -> Option<String> { |
| // 2 = ` {` |
| let path_shape = shape.sub_width(2)?; |
| let path_str = rewrite_path(context, PathContext::Expr, qself, path, path_shape)?; |
| |
| if fields.is_empty() && !ellipsis { |
| return Some(format!("{path_str} {{}}")); |
| } |
| |
| let (ellipsis_str, terminator) = if ellipsis { (", ..", "..") } else { ("", "}") }; |
| |
| // 3 = ` { `, 2 = ` }`. |
| let (h_shape, v_shape) = |
| struct_lit_shape(shape, context, path_str.len() + 3, ellipsis_str.len() + 2)?; |
| |
| let items = itemize_list( |
| context.snippet_provider, |
| fields.iter(), |
| terminator, |
| ",", |
| |f| { |
| if f.attrs.is_empty() { |
| f.span.lo() |
| } else { |
| f.attrs.first().unwrap().span.lo() |
| } |
| }, |
| |f| f.span.hi(), |
| |f| f.rewrite(context, v_shape), |
| context.snippet_provider.span_after(span, "{"), |
| span.hi(), |
| false, |
| ); |
| let item_vec = items.collect::<Vec<_>>(); |
| |
| let tactic = struct_lit_tactic(h_shape, context, &item_vec); |
| let nested_shape = shape_for_tactic(tactic, h_shape, v_shape); |
| let fmt = struct_lit_formatting(nested_shape, tactic, context, false); |
| |
| let mut fields_str = write_list(&item_vec, &fmt)?; |
| let one_line_width = h_shape.map_or(0, |shape| shape.width); |
| |
| let has_trailing_comma = fmt.needs_trailing_separator(); |
| |
| if ellipsis { |
| if fields_str.contains('\n') || fields_str.len() > one_line_width { |
| // Add a missing trailing comma. |
| if !has_trailing_comma { |
| fields_str.push(','); |
| } |
| fields_str.push('\n'); |
| fields_str.push_str(&nested_shape.indent.to_string(context.config)); |
| } else { |
| if !fields_str.is_empty() { |
| // there are preceding struct fields being matched on |
| if has_trailing_comma { |
| fields_str.push(' '); |
| } else { |
| fields_str.push_str(", "); |
| } |
| } |
| } |
| fields_str.push_str(".."); |
| } |
| |
| // ast::Pat doesn't have attrs so use &[] |
| let fields_str = wrap_struct_field(context, &[], &fields_str, shape, v_shape, one_line_width)?; |
| Some(format!("{path_str} {{{fields_str}}}")) |
| } |
| |
| impl Rewrite for PatField { |
| fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> { |
| let hi_pos = if let Some(last) = self.attrs.last() { |
| last.span.hi() |
| } else { |
| self.pat.span.lo() |
| }; |
| |
| let attrs_str = if self.attrs.is_empty() { |
| String::from("") |
| } else { |
| self.attrs.rewrite(context, shape)? |
| }; |
| |
| let pat_str = self.pat.rewrite(context, shape)?; |
| if self.is_shorthand { |
| combine_strs_with_missing_comments( |
| context, |
| &attrs_str, |
| &pat_str, |
| mk_sp(hi_pos, self.pat.span.lo()), |
| shape, |
| false, |
| ) |
| } else { |
| let nested_shape = shape.block_indent(context.config.tab_spaces()); |
| let id_str = rewrite_ident(context, self.ident); |
| let one_line_width = id_str.len() + 2 + pat_str.len(); |
| let pat_and_id_str = if one_line_width <= shape.width { |
| format!("{id_str}: {pat_str}") |
| } else { |
| format!( |
| "{}:\n{}{}", |
| id_str, |
| nested_shape.indent.to_string(context.config), |
| self.pat.rewrite(context, nested_shape)? |
| ) |
| }; |
| combine_strs_with_missing_comments( |
| context, |
| &attrs_str, |
| &pat_and_id_str, |
| mk_sp(hi_pos, self.pat.span.lo()), |
| nested_shape, |
| false, |
| ) |
| } |
| } |
| } |
| |
| #[derive(Debug)] |
| pub(crate) enum TuplePatField<'a> { |
| Pat(&'a ptr::P<ast::Pat>), |
| Dotdot(Span), |
| } |
| |
| impl<'a> Rewrite for TuplePatField<'a> { |
| fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> { |
| match *self { |
| TuplePatField::Pat(p) => p.rewrite(context, shape), |
| TuplePatField::Dotdot(_) => Some("..".to_string()), |
| } |
| } |
| } |
| |
| impl<'a> Spanned for TuplePatField<'a> { |
| fn span(&self) -> Span { |
| match *self { |
| TuplePatField::Pat(p) => p.span(), |
| TuplePatField::Dotdot(span) => span, |
| } |
| } |
| } |
| |
| impl<'a> TuplePatField<'a> { |
| fn is_dotdot(&self) -> bool { |
| match self { |
| TuplePatField::Pat(pat) => matches!(pat.kind, ast::PatKind::Rest), |
| TuplePatField::Dotdot(_) => true, |
| } |
| } |
| } |
| |
| pub(crate) fn can_be_overflowed_pat( |
| context: &RewriteContext<'_>, |
| pat: &TuplePatField<'_>, |
| len: usize, |
| ) -> bool { |
| match *pat { |
| TuplePatField::Pat(pat) => match pat.kind { |
| ast::PatKind::Path(..) |
| | ast::PatKind::Tuple(..) |
| | ast::PatKind::Struct(..) |
| | ast::PatKind::TupleStruct(..) => context.use_block_indent() && len == 1, |
| ast::PatKind::Ref(ref p, _) | ast::PatKind::Box(ref p) => { |
| can_be_overflowed_pat(context, &TuplePatField::Pat(p), len) |
| } |
| ast::PatKind::Lit(ref expr) => can_be_overflowed_expr(context, expr, len), |
| _ => false, |
| }, |
| TuplePatField::Dotdot(..) => false, |
| } |
| } |
| |
| fn rewrite_tuple_pat( |
| pats: &[ptr::P<ast::Pat>], |
| path_str: Option<String>, |
| span: Span, |
| context: &RewriteContext<'_>, |
| shape: Shape, |
| ) -> Option<String> { |
| if pats.is_empty() { |
| return Some(format!("{}()", path_str.unwrap_or_default())); |
| } |
| let mut pat_vec: Vec<_> = pats.iter().map(TuplePatField::Pat).collect(); |
| |
| let wildcard_suffix_len = count_wildcard_suffix_len(context, &pat_vec, span, shape); |
| let (pat_vec, span) = if context.config.condense_wildcard_suffixes() && wildcard_suffix_len >= 2 |
| { |
| let new_item_count = 1 + pat_vec.len() - wildcard_suffix_len; |
| let sp = pat_vec[new_item_count - 1].span(); |
| let snippet = context.snippet(sp); |
| let lo = sp.lo() + BytePos(snippet.find_uncommented("_").unwrap() as u32); |
| pat_vec[new_item_count - 1] = TuplePatField::Dotdot(mk_sp_lo_plus_one(lo)); |
| ( |
| &pat_vec[..new_item_count], |
| mk_sp(span.lo(), lo + BytePos(1)), |
| ) |
| } else { |
| (&pat_vec[..], span) |
| }; |
| |
| let is_last_pat_dotdot = pat_vec.last().map_or(false, |p| p.is_dotdot()); |
| let add_comma = path_str.is_none() && pat_vec.len() == 1 && !is_last_pat_dotdot; |
| let path_str = path_str.unwrap_or_default(); |
| |
| overflow::rewrite_with_parens( |
| context, |
| &path_str, |
| pat_vec.iter(), |
| shape, |
| span, |
| context.config.max_width(), |
| if add_comma { |
| Some(SeparatorTactic::Always) |
| } else { |
| None |
| }, |
| ) |
| } |
| |
| fn count_wildcard_suffix_len( |
| context: &RewriteContext<'_>, |
| patterns: &[TuplePatField<'_>], |
| span: Span, |
| shape: Shape, |
| ) -> usize { |
| let mut suffix_len = 0; |
| |
| let items: Vec<_> = itemize_list( |
| context.snippet_provider, |
| patterns.iter(), |
| ")", |
| ",", |
| |item| item.span().lo(), |
| |item| item.span().hi(), |
| |item| item.rewrite(context, shape), |
| context.snippet_provider.span_after(span, "("), |
| span.hi() - BytePos(1), |
| false, |
| ) |
| .collect(); |
| |
| for item in items |
| .iter() |
| .rev() |
| .take_while(|i| matches!(i.item, Some(ref internal_string) if internal_string == "_")) |
| { |
| suffix_len += 1; |
| |
| if item.has_comment() { |
| break; |
| } |
| } |
| |
| suffix_len |
| } |