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Commit | Line | Data |
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cdc7bbd5 | 1 | use rustc_ast::ast::{self, BindingMode, Pat, PatField, PatKind, RangeEnd, RangeSyntax}; |
f20569fa XL |
2 | use rustc_ast::ptr; |
3 | use rustc_span::{BytePos, Span}; | |
4 | ||
5 | use crate::comment::{combine_strs_with_missing_comments, FindUncommented}; | |
6 | use crate::config::lists::*; | |
7 | use crate::expr::{can_be_overflowed_expr, rewrite_unary_prefix, wrap_struct_field}; | |
8 | use crate::lists::{ | |
9 | definitive_tactic, itemize_list, shape_for_tactic, struct_lit_formatting, struct_lit_shape, | |
10 | struct_lit_tactic, write_list, ListFormatting, ListItem, Separator, | |
11 | }; | |
12 | use crate::macros::{rewrite_macro, MacroPosition}; | |
13 | use crate::overflow; | |
14 | use crate::pairs::{rewrite_pair, PairParts}; | |
15 | use crate::rewrite::{Rewrite, RewriteContext}; | |
16 | use crate::shape::Shape; | |
17 | use crate::source_map::SpanUtils; | |
18 | use crate::spanned::Spanned; | |
19 | use crate::types::{rewrite_path, PathContext}; | |
cdc7bbd5 | 20 | use crate::utils::{format_mutability, mk_sp, mk_sp_lo_plus_one, rewrite_ident}; |
f20569fa XL |
21 | |
22 | /// Returns `true` if the given pattern is "short". | |
23 | /// A short pattern is defined by the following grammar: | |
24 | /// | |
25 | /// [small, ntp]: | |
26 | /// - single token | |
27 | /// - `&[single-line, ntp]` | |
28 | /// | |
29 | /// [small]: | |
30 | /// - `[small, ntp]` | |
31 | /// - unary tuple constructor `([small, ntp])` | |
32 | /// - `&[small]` | |
33 | pub(crate) fn is_short_pattern(pat: &ast::Pat, pat_str: &str) -> bool { | |
34 | // We also require that the pattern is reasonably 'small' with its literal width. | |
35 | pat_str.len() <= 20 && !pat_str.contains('\n') && is_short_pattern_inner(pat) | |
36 | } | |
37 | ||
38 | fn is_short_pattern_inner(pat: &ast::Pat) -> bool { | |
39 | match pat.kind { | |
40 | ast::PatKind::Rest | ast::PatKind::Wild | ast::PatKind::Lit(_) => true, | |
41 | ast::PatKind::Ident(_, _, ref pat) => pat.is_none(), | |
42 | ast::PatKind::Struct(..) | |
43 | | ast::PatKind::MacCall(..) | |
44 | | ast::PatKind::Slice(..) | |
45 | | ast::PatKind::Path(..) | |
46 | | ast::PatKind::Range(..) => false, | |
47 | ast::PatKind::Tuple(ref subpats) => subpats.len() <= 1, | |
48 | ast::PatKind::TupleStruct(ref path, ref subpats) => { | |
49 | path.segments.len() <= 1 && subpats.len() <= 1 | |
50 | } | |
51 | ast::PatKind::Box(ref p) | ast::PatKind::Ref(ref p, _) | ast::PatKind::Paren(ref p) => { | |
52 | is_short_pattern_inner(&*p) | |
53 | } | |
54 | PatKind::Or(ref pats) => pats.iter().all(|p| is_short_pattern_inner(p)), | |
55 | } | |
56 | } | |
57 | ||
58 | struct RangeOperand<'a>(&'a Option<ptr::P<ast::Expr>>); | |
59 | ||
60 | impl<'a> Rewrite for RangeOperand<'a> { | |
61 | fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> { | |
62 | match &self.0 { | |
63 | None => Some("".to_owned()), | |
64 | Some(ref exp) => exp.rewrite(context, shape), | |
65 | } | |
66 | } | |
67 | } | |
68 | ||
69 | impl Rewrite for Pat { | |
70 | fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> { | |
71 | match self.kind { | |
72 | PatKind::Or(ref pats) => { | |
73 | let pat_strs = pats | |
74 | .iter() | |
75 | .map(|p| p.rewrite(context, shape)) | |
76 | .collect::<Option<Vec<_>>>()?; | |
77 | ||
78 | let use_mixed_layout = pats | |
79 | .iter() | |
80 | .zip(pat_strs.iter()) | |
81 | .all(|(pat, pat_str)| is_short_pattern(pat, pat_str)); | |
82 | let items: Vec<_> = pat_strs.into_iter().map(ListItem::from_str).collect(); | |
83 | let tactic = if use_mixed_layout { | |
84 | DefinitiveListTactic::Mixed | |
85 | } else { | |
86 | definitive_tactic( | |
87 | &items, | |
88 | ListTactic::HorizontalVertical, | |
89 | Separator::VerticalBar, | |
90 | shape.width, | |
91 | ) | |
92 | }; | |
93 | let fmt = ListFormatting::new(shape, context.config) | |
94 | .tactic(tactic) | |
95 | .separator(" |") | |
96 | .separator_place(context.config.binop_separator()) | |
97 | .ends_with_newline(false); | |
98 | write_list(&items, &fmt) | |
99 | } | |
100 | PatKind::Box(ref pat) => rewrite_unary_prefix(context, "box ", &**pat, shape), | |
101 | PatKind::Ident(binding_mode, ident, ref sub_pat) => { | |
102 | let (prefix, mutability) = match binding_mode { | |
103 | BindingMode::ByRef(mutability) => ("ref", mutability), | |
104 | BindingMode::ByValue(mutability) => ("", mutability), | |
105 | }; | |
106 | let mut_infix = format_mutability(mutability).trim(); | |
107 | let id_str = rewrite_ident(context, ident); | |
108 | let sub_pat = match *sub_pat { | |
109 | Some(ref p) => { | |
110 | // 2 - `@ `. | |
111 | let width = shape | |
112 | .width | |
113 | .checked_sub(prefix.len() + mut_infix.len() + id_str.len() + 2)?; | |
114 | let lo = context.snippet_provider.span_after(self.span, "@"); | |
115 | combine_strs_with_missing_comments( | |
116 | context, | |
117 | "@", | |
118 | &p.rewrite(context, Shape::legacy(width, shape.indent))?, | |
119 | mk_sp(lo, p.span.lo()), | |
120 | shape, | |
121 | true, | |
122 | )? | |
123 | } | |
124 | None => "".to_owned(), | |
125 | }; | |
126 | ||
127 | // combine prefix and mut | |
128 | let (first_lo, first) = if !prefix.is_empty() && !mut_infix.is_empty() { | |
129 | let hi = context.snippet_provider.span_before(self.span, "mut"); | |
130 | let lo = context.snippet_provider.span_after(self.span, "ref"); | |
131 | ( | |
132 | context.snippet_provider.span_after(self.span, "mut"), | |
133 | combine_strs_with_missing_comments( | |
134 | context, | |
135 | prefix, | |
136 | mut_infix, | |
137 | mk_sp(lo, hi), | |
138 | shape, | |
139 | true, | |
140 | )?, | |
141 | ) | |
142 | } else if !prefix.is_empty() { | |
143 | ( | |
144 | context.snippet_provider.span_after(self.span, "ref"), | |
145 | prefix.to_owned(), | |
146 | ) | |
147 | } else if !mut_infix.is_empty() { | |
148 | ( | |
149 | context.snippet_provider.span_after(self.span, "mut"), | |
150 | mut_infix.to_owned(), | |
151 | ) | |
152 | } else { | |
153 | (self.span.lo(), "".to_owned()) | |
154 | }; | |
155 | ||
156 | let next = if !sub_pat.is_empty() { | |
157 | let hi = context.snippet_provider.span_before(self.span, "@"); | |
158 | combine_strs_with_missing_comments( | |
159 | context, | |
160 | id_str, | |
161 | &sub_pat, | |
162 | mk_sp(ident.span.hi(), hi), | |
163 | shape, | |
164 | true, | |
165 | )? | |
166 | } else { | |
167 | id_str.to_owned() | |
168 | }; | |
169 | ||
170 | combine_strs_with_missing_comments( | |
171 | context, | |
172 | &first, | |
173 | &next, | |
174 | mk_sp(first_lo, ident.span.lo()), | |
175 | shape, | |
176 | true, | |
177 | ) | |
178 | } | |
179 | PatKind::Wild => { | |
180 | if 1 <= shape.width { | |
181 | Some("_".to_owned()) | |
182 | } else { | |
183 | None | |
184 | } | |
185 | } | |
186 | PatKind::Rest => { | |
187 | if 1 <= shape.width { | |
188 | Some("..".to_owned()) | |
189 | } else { | |
190 | None | |
191 | } | |
192 | } | |
193 | PatKind::Range(ref lhs, ref rhs, ref end_kind) => { | |
194 | let infix = match end_kind.node { | |
195 | RangeEnd::Included(RangeSyntax::DotDotDot) => "...", | |
196 | RangeEnd::Included(RangeSyntax::DotDotEq) => "..=", | |
197 | RangeEnd::Excluded => "..", | |
198 | }; | |
199 | let infix = if context.config.spaces_around_ranges() { | |
200 | let lhs_spacing = match lhs { | |
201 | None => "", | |
202 | Some(_) => " ", | |
203 | }; | |
204 | let rhs_spacing = match rhs { | |
205 | None => "", | |
206 | Some(_) => " ", | |
207 | }; | |
208 | format!("{}{}{}", lhs_spacing, infix, rhs_spacing) | |
209 | } else { | |
210 | infix.to_owned() | |
211 | }; | |
212 | rewrite_pair( | |
213 | &RangeOperand(lhs), | |
214 | &RangeOperand(rhs), | |
215 | PairParts::infix(&infix), | |
216 | context, | |
217 | shape, | |
218 | SeparatorPlace::Front, | |
219 | ) | |
220 | } | |
221 | PatKind::Ref(ref pat, mutability) => { | |
222 | let prefix = format!("&{}", format_mutability(mutability)); | |
223 | rewrite_unary_prefix(context, &prefix, &**pat, shape) | |
224 | } | |
225 | PatKind::Tuple(ref items) => rewrite_tuple_pat(items, None, self.span, context, shape), | |
226 | PatKind::Path(ref q_self, ref path) => { | |
227 | rewrite_path(context, PathContext::Expr, q_self.as_ref(), path, shape) | |
228 | } | |
229 | PatKind::TupleStruct(ref path, ref pat_vec) => { | |
230 | let path_str = rewrite_path(context, PathContext::Expr, None, path, shape)?; | |
231 | rewrite_tuple_pat(pat_vec, Some(path_str), self.span, context, shape) | |
232 | } | |
233 | PatKind::Lit(ref expr) => expr.rewrite(context, shape), | |
234 | PatKind::Slice(ref slice_pat) => { | |
235 | let rw: Vec<String> = slice_pat | |
236 | .iter() | |
237 | .map(|p| { | |
238 | if let Some(rw) = p.rewrite(context, shape) { | |
239 | rw | |
240 | } else { | |
241 | format!("{}", context.snippet(p.span)) | |
242 | } | |
243 | }) | |
244 | .collect(); | |
245 | Some(format!("[{}]", rw.join(", "))) | |
246 | } | |
247 | PatKind::Struct(ref path, ref fields, ellipsis) => { | |
248 | rewrite_struct_pat(path, fields, ellipsis, self.span, context, shape) | |
249 | } | |
250 | PatKind::MacCall(ref mac) => { | |
251 | rewrite_macro(mac, None, context, shape, MacroPosition::Pat) | |
252 | } | |
253 | PatKind::Paren(ref pat) => pat | |
254 | .rewrite(context, shape.offset_left(1)?.sub_width(1)?) | |
255 | .map(|inner_pat| format!("({})", inner_pat)), | |
256 | } | |
257 | } | |
258 | } | |
259 | ||
260 | fn rewrite_struct_pat( | |
261 | path: &ast::Path, | |
cdc7bbd5 | 262 | fields: &[ast::PatField], |
f20569fa XL |
263 | ellipsis: bool, |
264 | span: Span, | |
265 | context: &RewriteContext<'_>, | |
266 | shape: Shape, | |
267 | ) -> Option<String> { | |
268 | // 2 = ` {` | |
269 | let path_shape = shape.sub_width(2)?; | |
270 | let path_str = rewrite_path(context, PathContext::Expr, None, path, path_shape)?; | |
271 | ||
272 | if fields.is_empty() && !ellipsis { | |
273 | return Some(format!("{} {{}}", path_str)); | |
274 | } | |
275 | ||
276 | let (ellipsis_str, terminator) = if ellipsis { (", ..", "..") } else { ("", "}") }; | |
277 | ||
278 | // 3 = ` { `, 2 = ` }`. | |
279 | let (h_shape, v_shape) = | |
280 | struct_lit_shape(shape, context, path_str.len() + 3, ellipsis_str.len() + 2)?; | |
281 | ||
282 | let items = itemize_list( | |
283 | context.snippet_provider, | |
284 | fields.iter(), | |
285 | terminator, | |
286 | ",", | |
287 | |f| { | |
288 | if f.attrs.is_empty() { | |
289 | f.span.lo() | |
290 | } else { | |
291 | f.attrs.first().unwrap().span.lo() | |
292 | } | |
293 | }, | |
294 | |f| f.span.hi(), | |
295 | |f| f.rewrite(context, v_shape), | |
296 | context.snippet_provider.span_after(span, "{"), | |
297 | span.hi(), | |
298 | false, | |
299 | ); | |
300 | let item_vec = items.collect::<Vec<_>>(); | |
301 | ||
302 | let tactic = struct_lit_tactic(h_shape, context, &item_vec); | |
303 | let nested_shape = shape_for_tactic(tactic, h_shape, v_shape); | |
304 | let fmt = struct_lit_formatting(nested_shape, tactic, context, false); | |
305 | ||
306 | let mut fields_str = write_list(&item_vec, &fmt)?; | |
307 | let one_line_width = h_shape.map_or(0, |shape| shape.width); | |
308 | ||
309 | if ellipsis { | |
310 | if fields_str.contains('\n') || fields_str.len() > one_line_width { | |
311 | // Add a missing trailing comma. | |
312 | if context.config.trailing_comma() == SeparatorTactic::Never { | |
313 | fields_str.push_str(","); | |
314 | } | |
315 | fields_str.push_str("\n"); | |
316 | fields_str.push_str(&nested_shape.indent.to_string(context.config)); | |
317 | fields_str.push_str(".."); | |
318 | } else { | |
319 | if !fields_str.is_empty() { | |
320 | // there are preceding struct fields being matched on | |
321 | if tactic == DefinitiveListTactic::Vertical { | |
322 | // if the tactic is Vertical, write_list already added a trailing , | |
323 | fields_str.push_str(" "); | |
324 | } else { | |
325 | fields_str.push_str(", "); | |
326 | } | |
327 | } | |
328 | fields_str.push_str(".."); | |
329 | } | |
330 | } | |
331 | ||
332 | // ast::Pat doesn't have attrs so use &[] | |
333 | let fields_str = wrap_struct_field(context, &[], &fields_str, shape, v_shape, one_line_width)?; | |
334 | Some(format!("{} {{{}}}", path_str, fields_str)) | |
335 | } | |
336 | ||
cdc7bbd5 | 337 | impl Rewrite for PatField { |
f20569fa XL |
338 | fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> { |
339 | let hi_pos = if let Some(last) = self.attrs.last() { | |
340 | last.span.hi() | |
341 | } else { | |
342 | self.pat.span.lo() | |
343 | }; | |
344 | ||
345 | let attrs_str = if self.attrs.is_empty() { | |
346 | String::from("") | |
347 | } else { | |
348 | self.attrs.rewrite(context, shape)? | |
349 | }; | |
350 | ||
351 | let pat_str = self.pat.rewrite(context, shape)?; | |
352 | if self.is_shorthand { | |
353 | combine_strs_with_missing_comments( | |
354 | context, | |
355 | &attrs_str, | |
356 | &pat_str, | |
357 | mk_sp(hi_pos, self.pat.span.lo()), | |
358 | shape, | |
359 | false, | |
360 | ) | |
361 | } else { | |
362 | let nested_shape = shape.block_indent(context.config.tab_spaces()); | |
363 | let id_str = rewrite_ident(context, self.ident); | |
364 | let one_line_width = id_str.len() + 2 + pat_str.len(); | |
365 | let pat_and_id_str = if one_line_width <= shape.width { | |
366 | format!("{}: {}", id_str, pat_str) | |
367 | } else { | |
368 | format!( | |
369 | "{}:\n{}{}", | |
370 | id_str, | |
371 | nested_shape.indent.to_string(context.config), | |
372 | self.pat.rewrite(context, nested_shape)? | |
373 | ) | |
374 | }; | |
375 | combine_strs_with_missing_comments( | |
376 | context, | |
377 | &attrs_str, | |
378 | &pat_and_id_str, | |
379 | mk_sp(hi_pos, self.pat.span.lo()), | |
380 | nested_shape, | |
381 | false, | |
382 | ) | |
383 | } | |
384 | } | |
385 | } | |
386 | ||
387 | #[derive(Debug)] | |
388 | pub(crate) enum TuplePatField<'a> { | |
389 | Pat(&'a ptr::P<ast::Pat>), | |
390 | Dotdot(Span), | |
391 | } | |
392 | ||
393 | impl<'a> Rewrite for TuplePatField<'a> { | |
394 | fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> { | |
395 | match *self { | |
396 | TuplePatField::Pat(p) => p.rewrite(context, shape), | |
397 | TuplePatField::Dotdot(_) => Some("..".to_string()), | |
398 | } | |
399 | } | |
400 | } | |
401 | ||
402 | impl<'a> Spanned for TuplePatField<'a> { | |
403 | fn span(&self) -> Span { | |
404 | match *self { | |
405 | TuplePatField::Pat(p) => p.span(), | |
406 | TuplePatField::Dotdot(span) => span, | |
407 | } | |
408 | } | |
409 | } | |
410 | ||
411 | impl<'a> TuplePatField<'a> { | |
412 | fn is_dotdot(&self) -> bool { | |
413 | match self { | |
414 | TuplePatField::Pat(pat) => match pat.kind { | |
415 | ast::PatKind::Rest => true, | |
416 | _ => false, | |
417 | }, | |
418 | TuplePatField::Dotdot(_) => true, | |
419 | } | |
420 | } | |
421 | } | |
422 | ||
423 | pub(crate) fn can_be_overflowed_pat( | |
424 | context: &RewriteContext<'_>, | |
425 | pat: &TuplePatField<'_>, | |
426 | len: usize, | |
427 | ) -> bool { | |
428 | match *pat { | |
429 | TuplePatField::Pat(pat) => match pat.kind { | |
430 | ast::PatKind::Path(..) | |
431 | | ast::PatKind::Tuple(..) | |
432 | | ast::PatKind::Struct(..) | |
433 | | ast::PatKind::TupleStruct(..) => context.use_block_indent() && len == 1, | |
434 | ast::PatKind::Ref(ref p, _) | ast::PatKind::Box(ref p) => { | |
435 | can_be_overflowed_pat(context, &TuplePatField::Pat(p), len) | |
436 | } | |
437 | ast::PatKind::Lit(ref expr) => can_be_overflowed_expr(context, expr, len), | |
438 | _ => false, | |
439 | }, | |
440 | TuplePatField::Dotdot(..) => false, | |
441 | } | |
442 | } | |
443 | ||
444 | fn rewrite_tuple_pat( | |
445 | pats: &[ptr::P<ast::Pat>], | |
446 | path_str: Option<String>, | |
447 | span: Span, | |
448 | context: &RewriteContext<'_>, | |
449 | shape: Shape, | |
450 | ) -> Option<String> { | |
451 | let mut pat_vec: Vec<_> = pats.iter().map(|x| TuplePatField::Pat(x)).collect(); | |
452 | ||
453 | if pat_vec.is_empty() { | |
454 | return Some(format!("{}()", path_str.unwrap_or_default())); | |
455 | } | |
456 | let wildcard_suffix_len = count_wildcard_suffix_len(context, &pat_vec, span, shape); | |
457 | let (pat_vec, span) = if context.config.condense_wildcard_suffixes() && wildcard_suffix_len >= 2 | |
458 | { | |
459 | let new_item_count = 1 + pat_vec.len() - wildcard_suffix_len; | |
460 | let sp = pat_vec[new_item_count - 1].span(); | |
461 | let snippet = context.snippet(sp); | |
462 | let lo = sp.lo() + BytePos(snippet.find_uncommented("_").unwrap() as u32); | |
cdc7bbd5 | 463 | pat_vec[new_item_count - 1] = TuplePatField::Dotdot(mk_sp_lo_plus_one(lo)); |
f20569fa XL |
464 | ( |
465 | &pat_vec[..new_item_count], | |
466 | mk_sp(span.lo(), lo + BytePos(1)), | |
467 | ) | |
468 | } else { | |
469 | (&pat_vec[..], span) | |
470 | }; | |
471 | ||
472 | let is_last_pat_dotdot = pat_vec.last().map_or(false, |p| p.is_dotdot()); | |
473 | let add_comma = path_str.is_none() && pat_vec.len() == 1 && !is_last_pat_dotdot; | |
474 | let path_str = path_str.unwrap_or_default(); | |
475 | ||
476 | overflow::rewrite_with_parens( | |
477 | &context, | |
478 | &path_str, | |
479 | pat_vec.iter(), | |
480 | shape, | |
481 | span, | |
482 | context.config.max_width(), | |
483 | if add_comma { | |
484 | Some(SeparatorTactic::Always) | |
485 | } else { | |
486 | None | |
487 | }, | |
488 | ) | |
489 | } | |
490 | ||
491 | fn count_wildcard_suffix_len( | |
492 | context: &RewriteContext<'_>, | |
493 | patterns: &[TuplePatField<'_>], | |
494 | span: Span, | |
495 | shape: Shape, | |
496 | ) -> usize { | |
497 | let mut suffix_len = 0; | |
498 | ||
499 | let items: Vec<_> = itemize_list( | |
500 | context.snippet_provider, | |
501 | patterns.iter(), | |
502 | ")", | |
503 | ",", | |
504 | |item| item.span().lo(), | |
505 | |item| item.span().hi(), | |
506 | |item| item.rewrite(context, shape), | |
507 | context.snippet_provider.span_after(span, "("), | |
508 | span.hi() - BytePos(1), | |
509 | false, | |
510 | ) | |
511 | .collect(); | |
512 | ||
513 | for item in items.iter().rev().take_while(|i| match i.item { | |
514 | Some(ref internal_string) if internal_string == "_" => true, | |
515 | _ => false, | |
516 | }) { | |
517 | suffix_len += 1; | |
518 | ||
519 | if item.has_comment() { | |
520 | break; | |
521 | } | |
522 | } | |
523 | ||
524 | suffix_len | |
525 | } |