1 use crate::pp::Breaks::Inconsistent;
2 use crate::pprust::state::{AnnNode, IterDelimited, PrintState, State, INDENT_UNIT};
3
4 use rustc_ast::ptr::P;
5 use rustc_ast::token;
6 use rustc_ast::util::literal::escape_byte_str_symbol;
7 use rustc_ast::util::parser::{self, AssocOp, Fixity};
8 use rustc_ast::{self as ast, BlockCheckMode};
9 use rustc_ast::{
10 FormatAlignment, FormatArgPosition, FormatArgsPiece, FormatCount, FormatDebugHex, FormatSign,
11 FormatTrait,
12 };
13 use std::fmt::Write;
14
15 impl<'a> State<'a> {
print_else(&mut self, els: Option<&ast::Expr>)16 fn print_else(&mut self, els: Option<&ast::Expr>) {
17 if let Some(_else) = els {
18 match &_else.kind {
19 // Another `else if` block.
20 ast::ExprKind::If(i, then, e) => {
21 self.cbox(INDENT_UNIT - 1);
22 self.ibox(0);
23 self.word(" else if ");
24 self.print_expr_as_cond(i);
25 self.space();
26 self.print_block(then);
27 self.print_else(e.as_deref())
28 }
29 // Final `else` block.
30 ast::ExprKind::Block(b, _) => {
31 self.cbox(INDENT_UNIT - 1);
32 self.ibox(0);
33 self.word(" else ");
34 self.print_block(b)
35 }
36 // Constraints would be great here!
37 _ => {
38 panic!("print_if saw if with weird alternative");
39 }
40 }
41 }
42 }
43
print_if(&mut self, test: &ast::Expr, blk: &ast::Block, elseopt: Option<&ast::Expr>)44 fn print_if(&mut self, test: &ast::Expr, blk: &ast::Block, elseopt: Option<&ast::Expr>) {
45 self.head("if");
46 self.print_expr_as_cond(test);
47 self.space();
48 self.print_block(blk);
49 self.print_else(elseopt)
50 }
51
print_call_post(&mut self, args: &[P<ast::Expr>])52 fn print_call_post(&mut self, args: &[P<ast::Expr>]) {
53 self.popen();
54 self.commasep_exprs(Inconsistent, args);
55 self.pclose()
56 }
57
print_expr_maybe_paren(&mut self, expr: &ast::Expr, prec: i8)58 fn print_expr_maybe_paren(&mut self, expr: &ast::Expr, prec: i8) {
59 self.print_expr_cond_paren(expr, expr.precedence().order() < prec)
60 }
61
62 /// Prints an expr using syntax that's acceptable in a condition position, such as the `cond` in
63 /// `if cond { ... }`.
print_expr_as_cond(&mut self, expr: &ast::Expr)64 fn print_expr_as_cond(&mut self, expr: &ast::Expr) {
65 self.print_expr_cond_paren(expr, Self::cond_needs_par(expr))
66 }
67
68 /// Does `expr` need parentheses when printed in a condition position?
69 ///
70 /// These cases need parens due to the parse error observed in #26461: `if return {}`
71 /// parses as the erroneous construct `if (return {})`, not `if (return) {}`.
cond_needs_par(expr: &ast::Expr) -> bool72 pub(super) fn cond_needs_par(expr: &ast::Expr) -> bool {
73 match expr.kind {
74 ast::ExprKind::Break(..)
75 | ast::ExprKind::Closure(..)
76 | ast::ExprKind::Ret(..)
77 | ast::ExprKind::Yeet(..) => true,
78 _ => parser::contains_exterior_struct_lit(expr),
79 }
80 }
81
82 /// Prints `expr` or `(expr)` when `needs_par` holds.
print_expr_cond_paren(&mut self, expr: &ast::Expr, needs_par: bool)83 pub(super) fn print_expr_cond_paren(&mut self, expr: &ast::Expr, needs_par: bool) {
84 if needs_par {
85 self.popen();
86 }
87 self.print_expr(expr);
88 if needs_par {
89 self.pclose();
90 }
91 }
92
print_expr_vec(&mut self, exprs: &[P<ast::Expr>])93 fn print_expr_vec(&mut self, exprs: &[P<ast::Expr>]) {
94 self.ibox(INDENT_UNIT);
95 self.word("[");
96 self.commasep_exprs(Inconsistent, exprs);
97 self.word("]");
98 self.end();
99 }
100
print_expr_anon_const( &mut self, expr: &ast::AnonConst, attrs: &[ast::Attribute], )101 pub(super) fn print_expr_anon_const(
102 &mut self,
103 expr: &ast::AnonConst,
104 attrs: &[ast::Attribute],
105 ) {
106 self.ibox(INDENT_UNIT);
107 self.word("const");
108 self.nbsp();
109 if let ast::ExprKind::Block(block, None) = &expr.value.kind {
110 self.cbox(0);
111 self.ibox(0);
112 self.print_block_with_attrs(block, attrs);
113 } else {
114 self.print_expr(&expr.value);
115 }
116 self.end();
117 }
118
print_expr_repeat(&mut self, element: &ast::Expr, count: &ast::AnonConst)119 fn print_expr_repeat(&mut self, element: &ast::Expr, count: &ast::AnonConst) {
120 self.ibox(INDENT_UNIT);
121 self.word("[");
122 self.print_expr(element);
123 self.word_space(";");
124 self.print_expr(&count.value);
125 self.word("]");
126 self.end();
127 }
128
print_expr_struct( &mut self, qself: &Option<P<ast::QSelf>>, path: &ast::Path, fields: &[ast::ExprField], rest: &ast::StructRest, )129 fn print_expr_struct(
130 &mut self,
131 qself: &Option<P<ast::QSelf>>,
132 path: &ast::Path,
133 fields: &[ast::ExprField],
134 rest: &ast::StructRest,
135 ) {
136 if let Some(qself) = qself {
137 self.print_qpath(path, qself, true);
138 } else {
139 self.print_path(path, true, 0);
140 }
141 self.nbsp();
142 self.word("{");
143 let has_rest = match rest {
144 ast::StructRest::Base(_) | ast::StructRest::Rest(_) => true,
145 ast::StructRest::None => false,
146 };
147 if fields.is_empty() && !has_rest {
148 self.word("}");
149 return;
150 }
151 self.cbox(0);
152 for field in fields.iter().delimited() {
153 self.maybe_print_comment(field.span.hi());
154 self.print_outer_attributes(&field.attrs);
155 if field.is_first {
156 self.space_if_not_bol();
157 }
158 if !field.is_shorthand {
159 self.print_ident(field.ident);
160 self.word_nbsp(":");
161 }
162 self.print_expr(&field.expr);
163 if !field.is_last || has_rest {
164 self.word_space(",");
165 } else {
166 self.trailing_comma_or_space();
167 }
168 }
169 if has_rest {
170 if fields.is_empty() {
171 self.space();
172 }
173 self.word("..");
174 if let ast::StructRest::Base(expr) = rest {
175 self.print_expr(expr);
176 }
177 self.space();
178 }
179 self.offset(-INDENT_UNIT);
180 self.end();
181 self.word("}");
182 }
183
print_expr_tup(&mut self, exprs: &[P<ast::Expr>])184 fn print_expr_tup(&mut self, exprs: &[P<ast::Expr>]) {
185 self.popen();
186 self.commasep_exprs(Inconsistent, exprs);
187 if exprs.len() == 1 {
188 self.word(",");
189 }
190 self.pclose()
191 }
192
print_expr_call(&mut self, func: &ast::Expr, args: &[P<ast::Expr>])193 fn print_expr_call(&mut self, func: &ast::Expr, args: &[P<ast::Expr>]) {
194 let prec = match func.kind {
195 ast::ExprKind::Field(..) => parser::PREC_FORCE_PAREN,
196 _ => parser::PREC_POSTFIX,
197 };
198
199 self.print_expr_maybe_paren(func, prec);
200 self.print_call_post(args)
201 }
202
print_expr_method_call( &mut self, segment: &ast::PathSegment, receiver: &ast::Expr, base_args: &[P<ast::Expr>], )203 fn print_expr_method_call(
204 &mut self,
205 segment: &ast::PathSegment,
206 receiver: &ast::Expr,
207 base_args: &[P<ast::Expr>],
208 ) {
209 self.print_expr_maybe_paren(receiver, parser::PREC_POSTFIX);
210 self.word(".");
211 self.print_ident(segment.ident);
212 if let Some(args) = &segment.args {
213 self.print_generic_args(args, true);
214 }
215 self.print_call_post(base_args)
216 }
217
print_expr_binary(&mut self, op: ast::BinOp, lhs: &ast::Expr, rhs: &ast::Expr)218 fn print_expr_binary(&mut self, op: ast::BinOp, lhs: &ast::Expr, rhs: &ast::Expr) {
219 let assoc_op = AssocOp::from_ast_binop(op.node);
220 let prec = assoc_op.precedence() as i8;
221 let fixity = assoc_op.fixity();
222
223 let (left_prec, right_prec) = match fixity {
224 Fixity::Left => (prec, prec + 1),
225 Fixity::Right => (prec + 1, prec),
226 Fixity::None => (prec + 1, prec + 1),
227 };
228
229 let left_prec = match (&lhs.kind, op.node) {
230 // These cases need parens: `x as i32 < y` has the parser thinking that `i32 < y` is
231 // the beginning of a path type. It starts trying to parse `x as (i32 < y ...` instead
232 // of `(x as i32) < ...`. We need to convince it _not_ to do that.
233 (&ast::ExprKind::Cast { .. }, ast::BinOpKind::Lt | ast::BinOpKind::Shl) => {
234 parser::PREC_FORCE_PAREN
235 }
236 // We are given `(let _ = a) OP b`.
237 //
238 // - When `OP <= LAnd` we should print `let _ = a OP b` to avoid redundant parens
239 // as the parser will interpret this as `(let _ = a) OP b`.
240 //
241 // - Otherwise, e.g. when we have `(let a = b) < c` in AST,
242 // parens are required since the parser would interpret `let a = b < c` as
243 // `let a = (b < c)`. To achieve this, we force parens.
244 (&ast::ExprKind::Let { .. }, _) if !parser::needs_par_as_let_scrutinee(prec) => {
245 parser::PREC_FORCE_PAREN
246 }
247 // For a binary expression like `(match () { _ => a }) OP b`, the parens are required
248 // otherwise the parser would interpret `match () { _ => a }` as a statement,
249 // with the remaining `OP b` not making sense. So we force parens.
250 (&ast::ExprKind::Match(..), _) => parser::PREC_FORCE_PAREN,
251 _ => left_prec,
252 };
253
254 self.print_expr_maybe_paren(lhs, left_prec);
255 self.space();
256 self.word_space(op.node.to_string());
257 self.print_expr_maybe_paren(rhs, right_prec)
258 }
259
print_expr_unary(&mut self, op: ast::UnOp, expr: &ast::Expr)260 fn print_expr_unary(&mut self, op: ast::UnOp, expr: &ast::Expr) {
261 self.word(ast::UnOp::to_string(op));
262 self.print_expr_maybe_paren(expr, parser::PREC_PREFIX)
263 }
264
print_expr_addr_of( &mut self, kind: ast::BorrowKind, mutability: ast::Mutability, expr: &ast::Expr, )265 fn print_expr_addr_of(
266 &mut self,
267 kind: ast::BorrowKind,
268 mutability: ast::Mutability,
269 expr: &ast::Expr,
270 ) {
271 self.word("&");
272 match kind {
273 ast::BorrowKind::Ref => self.print_mutability(mutability, false),
274 ast::BorrowKind::Raw => {
275 self.word_nbsp("raw");
276 self.print_mutability(mutability, true);
277 }
278 }
279 self.print_expr_maybe_paren(expr, parser::PREC_PREFIX)
280 }
281
print_expr(&mut self, expr: &ast::Expr)282 pub fn print_expr(&mut self, expr: &ast::Expr) {
283 self.print_expr_outer_attr_style(expr, true)
284 }
285
print_expr_outer_attr_style(&mut self, expr: &ast::Expr, is_inline: bool)286 pub(super) fn print_expr_outer_attr_style(&mut self, expr: &ast::Expr, is_inline: bool) {
287 self.maybe_print_comment(expr.span.lo());
288
289 let attrs = &expr.attrs;
290 if is_inline {
291 self.print_outer_attributes_inline(attrs);
292 } else {
293 self.print_outer_attributes(attrs);
294 }
295
296 self.ibox(INDENT_UNIT);
297 self.ann.pre(self, AnnNode::Expr(expr));
298 match &expr.kind {
299 ast::ExprKind::Array(exprs) => {
300 self.print_expr_vec(exprs);
301 }
302 ast::ExprKind::ConstBlock(anon_const) => {
303 self.print_expr_anon_const(anon_const, attrs);
304 }
305 ast::ExprKind::Repeat(element, count) => {
306 self.print_expr_repeat(element, count);
307 }
308 ast::ExprKind::Struct(se) => {
309 self.print_expr_struct(&se.qself, &se.path, &se.fields, &se.rest);
310 }
311 ast::ExprKind::Tup(exprs) => {
312 self.print_expr_tup(exprs);
313 }
314 ast::ExprKind::Call(func, args) => {
315 self.print_expr_call(func, args);
316 }
317 ast::ExprKind::MethodCall(box ast::MethodCall { seg, receiver, args, .. }) => {
318 self.print_expr_method_call(seg, receiver, args);
319 }
320 ast::ExprKind::Binary(op, lhs, rhs) => {
321 self.print_expr_binary(*op, lhs, rhs);
322 }
323 ast::ExprKind::Unary(op, expr) => {
324 self.print_expr_unary(*op, expr);
325 }
326 ast::ExprKind::AddrOf(k, m, expr) => {
327 self.print_expr_addr_of(*k, *m, expr);
328 }
329 ast::ExprKind::Lit(token_lit) => {
330 self.print_token_literal(*token_lit, expr.span);
331 }
332 ast::ExprKind::IncludedBytes(bytes) => {
333 let lit = token::Lit::new(token::ByteStr, escape_byte_str_symbol(bytes), None);
334 self.print_token_literal(lit, expr.span)
335 }
336 ast::ExprKind::Cast(expr, ty) => {
337 let prec = AssocOp::As.precedence() as i8;
338 self.print_expr_maybe_paren(expr, prec);
339 self.space();
340 self.word_space("as");
341 self.print_type(ty);
342 }
343 ast::ExprKind::Type(expr, ty) => {
344 self.word("type_ascribe!(");
345 self.ibox(0);
346 self.print_expr(expr);
347
348 self.word(",");
349 self.space_if_not_bol();
350 self.print_type(ty);
351
352 self.end();
353 self.word(")");
354 }
355 ast::ExprKind::Let(pat, scrutinee, _) => {
356 self.print_let(pat, scrutinee);
357 }
358 ast::ExprKind::If(test, blk, elseopt) => self.print_if(test, blk, elseopt.as_deref()),
359 ast::ExprKind::While(test, blk, opt_label) => {
360 if let Some(label) = opt_label {
361 self.print_ident(label.ident);
362 self.word_space(":");
363 }
364 self.cbox(0);
365 self.ibox(0);
366 self.word_nbsp("while");
367 self.print_expr_as_cond(test);
368 self.space();
369 self.print_block_with_attrs(blk, attrs);
370 }
371 ast::ExprKind::ForLoop(pat, iter, blk, opt_label) => {
372 if let Some(label) = opt_label {
373 self.print_ident(label.ident);
374 self.word_space(":");
375 }
376 self.cbox(0);
377 self.ibox(0);
378 self.word_nbsp("for");
379 self.print_pat(pat);
380 self.space();
381 self.word_space("in");
382 self.print_expr_as_cond(iter);
383 self.space();
384 self.print_block_with_attrs(blk, attrs);
385 }
386 ast::ExprKind::Loop(blk, opt_label, _) => {
387 if let Some(label) = opt_label {
388 self.print_ident(label.ident);
389 self.word_space(":");
390 }
391 self.cbox(0);
392 self.ibox(0);
393 self.word_nbsp("loop");
394 self.print_block_with_attrs(blk, attrs);
395 }
396 ast::ExprKind::Match(expr, arms) => {
397 self.cbox(0);
398 self.ibox(0);
399 self.word_nbsp("match");
400 self.print_expr_as_cond(expr);
401 self.space();
402 self.bopen();
403 self.print_inner_attributes_no_trailing_hardbreak(attrs);
404 for arm in arms {
405 self.print_arm(arm);
406 }
407 let empty = attrs.is_empty() && arms.is_empty();
408 self.bclose(expr.span, empty);
409 }
410 ast::ExprKind::Closure(box ast::Closure {
411 binder,
412 capture_clause,
413 constness,
414 asyncness,
415 movability,
416 fn_decl,
417 body,
418 fn_decl_span: _,
419 fn_arg_span: _,
420 }) => {
421 self.print_closure_binder(binder);
422 self.print_constness(*constness);
423 self.print_movability(*movability);
424 self.print_asyncness(*asyncness);
425 self.print_capture_clause(*capture_clause);
426
427 self.print_fn_params_and_ret(fn_decl, true);
428 self.space();
429 self.print_expr(body);
430 self.end(); // need to close a box
431
432 // a box will be closed by print_expr, but we didn't want an overall
433 // wrapper so we closed the corresponding opening. so create an
434 // empty box to satisfy the close.
435 self.ibox(0);
436 }
437 ast::ExprKind::Block(blk, opt_label) => {
438 if let Some(label) = opt_label {
439 self.print_ident(label.ident);
440 self.word_space(":");
441 }
442 // containing cbox, will be closed by print-block at }
443 self.cbox(0);
444 // head-box, will be closed by print-block after {
445 self.ibox(0);
446 self.print_block_with_attrs(blk, attrs);
447 }
448 ast::ExprKind::Async(capture_clause, blk) => {
449 self.word_nbsp("async");
450 self.print_capture_clause(*capture_clause);
451 // cbox/ibox in analogy to the `ExprKind::Block` arm above
452 self.cbox(0);
453 self.ibox(0);
454 self.print_block_with_attrs(blk, attrs);
455 }
456 ast::ExprKind::Await(expr, _) => {
457 self.print_expr_maybe_paren(expr, parser::PREC_POSTFIX);
458 self.word(".await");
459 }
460 ast::ExprKind::Assign(lhs, rhs, _) => {
461 let prec = AssocOp::Assign.precedence() as i8;
462 self.print_expr_maybe_paren(lhs, prec + 1);
463 self.space();
464 self.word_space("=");
465 self.print_expr_maybe_paren(rhs, prec);
466 }
467 ast::ExprKind::AssignOp(op, lhs, rhs) => {
468 let prec = AssocOp::Assign.precedence() as i8;
469 self.print_expr_maybe_paren(lhs, prec + 1);
470 self.space();
471 self.word(op.node.to_string());
472 self.word_space("=");
473 self.print_expr_maybe_paren(rhs, prec);
474 }
475 ast::ExprKind::Field(expr, ident) => {
476 self.print_expr_maybe_paren(expr, parser::PREC_POSTFIX);
477 self.word(".");
478 self.print_ident(*ident);
479 }
480 ast::ExprKind::Index(expr, index) => {
481 self.print_expr_maybe_paren(expr, parser::PREC_POSTFIX);
482 self.word("[");
483 self.print_expr(index);
484 self.word("]");
485 }
486 ast::ExprKind::Range(start, end, limits) => {
487 // Special case for `Range`. `AssocOp` claims that `Range` has higher precedence
488 // than `Assign`, but `x .. x = x` gives a parse error instead of `x .. (x = x)`.
489 // Here we use a fake precedence value so that any child with lower precedence than
490 // a "normal" binop gets parenthesized. (`LOr` is the lowest-precedence binop.)
491 let fake_prec = AssocOp::LOr.precedence() as i8;
492 if let Some(e) = start {
493 self.print_expr_maybe_paren(e, fake_prec);
494 }
495 match limits {
496 ast::RangeLimits::HalfOpen => self.word(".."),
497 ast::RangeLimits::Closed => self.word("..="),
498 }
499 if let Some(e) = end {
500 self.print_expr_maybe_paren(e, fake_prec);
501 }
502 }
503 ast::ExprKind::Underscore => self.word("_"),
504 ast::ExprKind::Path(None, path) => self.print_path(path, true, 0),
505 ast::ExprKind::Path(Some(qself), path) => self.print_qpath(path, qself, true),
506 ast::ExprKind::Break(opt_label, opt_expr) => {
507 self.word("break");
508 if let Some(label) = opt_label {
509 self.space();
510 self.print_ident(label.ident);
511 }
512 if let Some(expr) = opt_expr {
513 self.space();
514 self.print_expr_maybe_paren(expr, parser::PREC_JUMP);
515 }
516 }
517 ast::ExprKind::Continue(opt_label) => {
518 self.word("continue");
519 if let Some(label) = opt_label {
520 self.space();
521 self.print_ident(label.ident);
522 }
523 }
524 ast::ExprKind::Ret(result) => {
525 self.word("return");
526 if let Some(expr) = result {
527 self.word(" ");
528 self.print_expr_maybe_paren(expr, parser::PREC_JUMP);
529 }
530 }
531 ast::ExprKind::Yeet(result) => {
532 self.word("do");
533 self.word(" ");
534 self.word("yeet");
535 if let Some(expr) = result {
536 self.word(" ");
537 self.print_expr_maybe_paren(expr, parser::PREC_JUMP);
538 }
539 }
540 ast::ExprKind::Become(result) => {
541 self.word("become");
542 self.word(" ");
543 self.print_expr_maybe_paren(result, parser::PREC_JUMP);
544 }
545 ast::ExprKind::InlineAsm(a) => {
546 // FIXME: This should have its own syntax, distinct from a macro invocation.
547 self.word("asm!");
548 self.print_inline_asm(a);
549 }
550 ast::ExprKind::FormatArgs(fmt) => {
551 // FIXME: This should have its own syntax, distinct from a macro invocation.
552 self.word("format_args!");
553 self.popen();
554 self.rbox(0, Inconsistent);
555 self.word(reconstruct_format_args_template_string(&fmt.template));
556 for arg in fmt.arguments.all_args() {
557 self.word_space(",");
558 self.print_expr(&arg.expr);
559 }
560 self.end();
561 self.pclose();
562 }
563 ast::ExprKind::OffsetOf(container, fields) => {
564 self.word("builtin # offset_of");
565 self.popen();
566 self.rbox(0, Inconsistent);
567 self.print_type(container);
568 self.word(",");
569 self.space();
570
571 if let Some((&first, rest)) = fields.split_first() {
572 self.print_ident(first);
573
574 for &field in rest {
575 self.word(".");
576 self.print_ident(field);
577 }
578 }
579 self.pclose();
580 self.end();
581 }
582 ast::ExprKind::MacCall(m) => self.print_mac(m),
583 ast::ExprKind::Paren(e) => {
584 self.popen();
585 self.print_expr(e);
586 self.pclose();
587 }
588 ast::ExprKind::Yield(e) => {
589 self.word("yield");
590
591 if let Some(expr) = e {
592 self.space();
593 self.print_expr_maybe_paren(expr, parser::PREC_JUMP);
594 }
595 }
596 ast::ExprKind::Try(e) => {
597 self.print_expr_maybe_paren(e, parser::PREC_POSTFIX);
598 self.word("?")
599 }
600 ast::ExprKind::TryBlock(blk) => {
601 self.cbox(0);
602 self.ibox(0);
603 self.word_nbsp("try");
604 self.print_block_with_attrs(blk, attrs)
605 }
606 ast::ExprKind::Err => {
607 self.popen();
608 self.word("/*ERROR*/");
609 self.pclose()
610 }
611 }
612 self.ann.post(self, AnnNode::Expr(expr));
613 self.end();
614 }
615
print_arm(&mut self, arm: &ast::Arm)616 fn print_arm(&mut self, arm: &ast::Arm) {
617 // Note, I have no idea why this check is necessary, but here it is.
618 if arm.attrs.is_empty() {
619 self.space();
620 }
621 self.cbox(INDENT_UNIT);
622 self.ibox(0);
623 self.maybe_print_comment(arm.pat.span.lo());
624 self.print_outer_attributes(&arm.attrs);
625 self.print_pat(&arm.pat);
626 self.space();
627 if let Some(e) = &arm.guard {
628 self.word_space("if");
629 self.print_expr(e);
630 self.space();
631 }
632 self.word_space("=>");
633
634 match &arm.body.kind {
635 ast::ExprKind::Block(blk, opt_label) => {
636 if let Some(label) = opt_label {
637 self.print_ident(label.ident);
638 self.word_space(":");
639 }
640
641 // The block will close the pattern's ibox.
642 self.print_block_unclosed_indent(blk);
643
644 // If it is a user-provided unsafe block, print a comma after it.
645 if let BlockCheckMode::Unsafe(ast::UserProvided) = blk.rules {
646 self.word(",");
647 }
648 }
649 _ => {
650 self.end(); // Close the ibox for the pattern.
651 self.print_expr(&arm.body);
652 self.word(",");
653 }
654 }
655 self.end(); // Close enclosing cbox.
656 }
657
print_closure_binder(&mut self, binder: &ast::ClosureBinder)658 fn print_closure_binder(&mut self, binder: &ast::ClosureBinder) {
659 match binder {
660 ast::ClosureBinder::NotPresent => {}
661 ast::ClosureBinder::For { generic_params, .. } => {
662 self.print_formal_generic_params(generic_params)
663 }
664 }
665 }
666
print_movability(&mut self, movability: ast::Movability)667 fn print_movability(&mut self, movability: ast::Movability) {
668 match movability {
669 ast::Movability::Static => self.word_space("static"),
670 ast::Movability::Movable => {}
671 }
672 }
673
print_capture_clause(&mut self, capture_clause: ast::CaptureBy)674 fn print_capture_clause(&mut self, capture_clause: ast::CaptureBy) {
675 match capture_clause {
676 ast::CaptureBy::Value => self.word_space("move"),
677 ast::CaptureBy::Ref => {}
678 }
679 }
680 }
681
reconstruct_format_args_template_string(pieces: &[FormatArgsPiece]) -> String682 pub fn reconstruct_format_args_template_string(pieces: &[FormatArgsPiece]) -> String {
683 let mut template = "\"".to_string();
684 for piece in pieces {
685 match piece {
686 FormatArgsPiece::Literal(s) => {
687 for c in s.as_str().escape_debug() {
688 template.push(c);
689 if let '{' | '}' = c {
690 template.push(c);
691 }
692 }
693 }
694 FormatArgsPiece::Placeholder(p) => {
695 template.push('{');
696 let (Ok(n) | Err(n)) = p.argument.index;
697 write!(template, "{n}").unwrap();
698 if p.format_options != Default::default() || p.format_trait != FormatTrait::Display
699 {
700 template.push_str(":");
701 }
702 if let Some(fill) = p.format_options.fill {
703 template.push(fill);
704 }
705 match p.format_options.alignment {
706 Some(FormatAlignment::Left) => template.push_str("<"),
707 Some(FormatAlignment::Right) => template.push_str(">"),
708 Some(FormatAlignment::Center) => template.push_str("^"),
709 None => {}
710 }
711 match p.format_options.sign {
712 Some(FormatSign::Plus) => template.push('+'),
713 Some(FormatSign::Minus) => template.push('-'),
714 None => {}
715 }
716 if p.format_options.alternate {
717 template.push('#');
718 }
719 if p.format_options.zero_pad {
720 template.push('0');
721 }
722 if let Some(width) = &p.format_options.width {
723 match width {
724 FormatCount::Literal(n) => write!(template, "{n}").unwrap(),
725 FormatCount::Argument(FormatArgPosition {
726 index: Ok(n) | Err(n), ..
727 }) => {
728 write!(template, "{n}$").unwrap();
729 }
730 }
731 }
732 if let Some(precision) = &p.format_options.precision {
733 template.push('.');
734 match precision {
735 FormatCount::Literal(n) => write!(template, "{n}").unwrap(),
736 FormatCount::Argument(FormatArgPosition {
737 index: Ok(n) | Err(n), ..
738 }) => {
739 write!(template, "{n}$").unwrap();
740 }
741 }
742 }
743 match p.format_options.debug_hex {
744 Some(FormatDebugHex::Lower) => template.push('x'),
745 Some(FormatDebugHex::Upper) => template.push('X'),
746 None => {}
747 }
748 template.push_str(match p.format_trait {
749 FormatTrait::Display => "",
750 FormatTrait::Debug => "?",
751 FormatTrait::LowerExp => "e",
752 FormatTrait::UpperExp => "E",
753 FormatTrait::Octal => "o",
754 FormatTrait::Pointer => "p",
755 FormatTrait::Binary => "b",
756 FormatTrait::LowerHex => "x",
757 FormatTrait::UpperHex => "X",
758 });
759 template.push('}');
760 }
761 }
762 }
763 template.push('"');
764 template
765 }
766