16 pub(crate) const LITERAL_FIRST: TokenSet = TokenSet::new(&[
27 pub(crate) fn literal(p: &mut Parser) -> Option<CompletedMarker> {
28 if !p.at_ts(LITERAL_FIRST) {
33 Some(m.complete(p, LITERAL))
36 // E.g. for after the break in `if break {}`, this should not match
37 pub(super) const ATOM_EXPR_FIRST: TokenSet =
38 LITERAL_FIRST.union(paths::PATH_FIRST).union(TokenSet::new(&[
61 const EXPR_RECOVERY_SET: TokenSet = TokenSet::new(&[T![let]]);
63 pub(super) fn atom_expr(p: &mut Parser, r: Restrictions) -> Option<(CompletedMarker, BlockLike)> {
64 if let Some(m) = literal(p) {
65 return Some((m, BlockLike::NotBlock));
67 if paths::is_path_start(p) {
68 return Some(path_expr(p, r));
71 let done = match p.current() {
72 T!['('] => tuple_expr(p),
73 T!['['] => array_expr(p),
74 T![|] => closure_expr(p),
75 T![static] | T![async] | T![move] if la == T![|] => closure_expr(p),
76 T![static] | T![async] if la == T![move] && p.nth(2) == T![|] => closure_expr(p),
77 T![static] if la == T![async] && p.nth(2) == T![|] => closure_expr(p),
78 T![static] if la == T![async] && p.nth(2) == T![move] && p.nth(3) == T![|] => {
83 T![loop] => loop_expr(p, None),
84 T![box] => box_expr(p, None),
85 T![for] => for_expr(p, None),
86 T![while] => while_expr(p, None),
87 T![try] => try_block_expr(p, None),
88 LIFETIME_IDENT if la == T![:] => {
92 T![loop] => loop_expr(p, Some(m)),
93 T![for] => for_expr(p, Some(m)),
94 T![while] => while_expr(p, Some(m)),
96 // fn f() { 'label: {}; }
99 m.complete(p, BLOCK_EXPR)
102 // test_err misplaced_label_err
106 p.error("expected a loop");
107 m.complete(p, ERROR);
112 T![async] if la == T!['{'] || (la == T![move] && p.nth(2) == T!['{']) => {
117 m.complete(p, BLOCK_EXPR)
119 T![match] => match_expr(p),
121 // fn f() { unsafe { } }
122 T![unsafe] if la == T!['{'] => {
126 m.complete(p, BLOCK_EXPR)
129 // fn f() { const { } }
130 T![const] if la == T!['{'] => {
134 m.complete(p, BLOCK_EXPR)
137 // test for_range_from
145 m.complete(p, BLOCK_EXPR)
147 T![return] => return_expr(p),
148 T![yield] => yield_expr(p),
149 T![continue] => continue_expr(p),
150 T![break] => break_expr(p, r),
152 p.err_recover("expected expression", EXPR_RECOVERY_SET);
156 let blocklike = match done.kind() {
157 IF_EXPR | WHILE_EXPR | FOR_EXPR | LOOP_EXPR | MATCH_EXPR | BLOCK_EXPR => BlockLike::Block,
158 _ => BlockLike::NotBlock,
160 Some((done, blocklike))
169 fn tuple_expr(p: &mut Parser) -> CompletedMarker {
170 assert!(p.at(T!['(']));
174 let mut saw_comma = false;
175 let mut saw_expr = false;
176 while !p.at(EOF) && !p.at(T![')']) {
180 // const A: (i64, i64) = (1, #[cfg(test)] 2);
191 m.complete(p, if saw_expr && !saw_comma { PAREN_EXPR } else { TUPLE_EXPR })
201 fn array_expr(p: &mut Parser) -> CompletedMarker {
202 assert!(p.at(T!['[']));
205 let mut n_exprs = 0u32;
206 let mut has_semi = false;
209 while !p.at(EOF) && !p.at(T![']']) {
213 // const A: &[i64] = &[1, #[cfg(test)] 2];
218 if n_exprs == 1 && p.eat(T![;]) {
223 if has_semi || !p.at(T![']']) && !p.expect(T![,]) {
229 m.complete(p, ARRAY_EXPR)
242 // static move || {};
243 // static async || {};
244 // static async move || {};
246 fn closure_expr(p: &mut Parser) -> CompletedMarker {
249 || (p.at(T![move]) && p.nth(1) == T![|])
250 || (p.at(T![async]) && p.nth(1) == T![|])
251 || (p.at(T![async]) && p.nth(1) == T![move] && p.nth(2) == T![|])
252 || (p.at(T![static]) && p.nth(1) == T![|])
253 || (p.at(T![static]) && p.nth(1) == T![move] && p.nth(2) == T![|])
254 || (p.at(T![static]) && p.nth(1) == T![async] && p.nth(2) == T![|])
256 && p.nth(1) == T![async]
257 && p.nth(2) == T![move]
258 && p.nth(3) == T![|])
264 params::param_list_closure(p);
266 // test lambda_ret_block
267 // fn main() { || -> i32 { 92 }(); }
269 } else if p.at_ts(EXPR_FIRST) {
272 p.error("expected expression");
274 m.complete(p, CLOSURE_EXPR)
280 // if true {} else {};
281 // if true {} else if false {} else {};
283 // if { true } { } else { };
285 fn if_expr(p: &mut Parser) -> CompletedMarker {
286 assert!(p.at(T![if]));
299 m.complete(p, IF_EXPR)
306 // 'c: for x in () {}
308 fn label(p: &mut Parser) {
309 assert!(p.at(LIFETIME_IDENT) && p.nth(1) == T![:]);
313 m.complete(p, LABEL);
320 fn loop_expr(p: &mut Parser, m: Option<Marker>) -> CompletedMarker {
321 assert!(p.at(T![loop]));
322 let m = m.unwrap_or_else(|| p.start());
325 m.complete(p, LOOP_EXPR)
331 // while let Some(x) = it.next() {};
332 // while { true } {};
334 fn while_expr(p: &mut Parser, m: Option<Marker>) -> CompletedMarker {
335 assert!(p.at(T![while]));
336 let m = m.unwrap_or_else(|| p.start());
340 m.complete(p, WHILE_EXPR)
347 fn for_expr(p: &mut Parser, m: Option<Marker>) -> CompletedMarker {
348 assert!(p.at(T![for]));
349 let m = m.unwrap_or_else(|| p.start());
351 patterns::pattern(p);
355 m.complete(p, FOR_EXPR)
359 // fn foo() { if let Some(_) = None {} }
361 // if let Some(_) | Some(_) = None {}
362 // if let | Some(_) = None {}
363 // while let Some(_) | Some(_) = None {}
364 // while let | Some(_) = None {}
366 fn condition(p: &mut Parser) {
369 patterns::pattern_top(p);
373 m.complete(p, CONDITION);
380 // match { } { _ => () };
381 // match { S {} } {};
383 fn match_expr(p: &mut Parser) -> CompletedMarker {
384 assert!(p.at(T![match]));
391 p.error("expected `{`");
393 m.complete(p, MATCH_EXPR)
396 pub(crate) fn match_arm_list(p: &mut Parser) {
397 assert!(p.at(T!['{']));
401 // test match_arms_inner_attribute
404 // #![doc("Inner attribute")]
406 // #![doc("Stacked")]
410 attributes::inner_attrs(p);
412 while !p.at(EOF) && !p.at(T!['}']) {
414 error_block(p, "expected match arm");
420 m.complete(p, MATCH_ARM_LIST);
427 // _ if Test > Test{field: 0} => (),
429 // | X | Y if Z => (),
433 fn match_arm(p: &mut Parser) {
435 // test match_arms_outer_attributes
438 // #[cfg(feature = "some")]
440 // #[cfg(feature = "other")]
442 // #[cfg(feature = "many")]
443 // #[cfg(feature = "attributes")]
444 // #[cfg(feature = "before")]
448 attributes::outer_attrs(p);
450 patterns::pattern_top_r(p, TokenSet::EMPTY);
455 let blocklike = match expr_stmt(p, None) {
456 Some((_, blocklike)) => blocklike,
457 None => BlockLike::NotBlock,
460 // test match_arms_commas
468 if !p.eat(T![,]) && !blocklike.is_block() && !p.at(T!['}']) {
469 p.error("expected `,`");
471 m.complete(p, MATCH_ARM);
478 // _ if let foo = bar => (),
481 fn match_guard(p: &mut Parser) -> CompletedMarker {
482 assert!(p.at(T![if]));
486 patterns::pattern_top(p);
490 m.complete(p, MATCH_GUARD)
495 // fn b() { let _ = 1; }
498 pub(crate) fn block_expr(p: &mut Parser) {
500 p.error("expected a block");
505 m.complete(p, BLOCK_EXPR);
508 fn stmt_list(p: &mut Parser) -> CompletedMarker {
509 assert!(p.at(T!['{']));
512 expr_block_contents(p);
514 m.complete(p, STMT_LIST)
522 fn return_expr(p: &mut Parser) -> CompletedMarker {
523 assert!(p.at(T![return]));
526 if p.at_ts(EXPR_FIRST) {
529 m.complete(p, RETURN_EXPR)
536 fn yield_expr(p: &mut Parser) -> CompletedMarker {
537 assert!(p.at(T![yield]));
540 if p.at_ts(EXPR_FIRST) {
543 m.complete(p, YIELD_EXPR)
546 // test continue_expr
553 fn continue_expr(p: &mut Parser) -> CompletedMarker {
554 assert!(p.at(T![continue]));
556 p.bump(T![continue]);
557 if p.at(LIFETIME_IDENT) {
560 m.complete(p, CONTINUE_EXPR)
572 fn break_expr(p: &mut Parser, r: Restrictions) -> CompletedMarker {
573 assert!(p.at(T![break]));
576 if p.at(LIFETIME_IDENT) {
579 // test break_ambiguity
586 if p.at_ts(EXPR_FIRST) && !(r.forbid_structs && p.at(T!['{'])) {
589 m.complete(p, BREAK_EXPR)
592 // test try_block_expr
596 fn try_block_expr(p: &mut Parser, m: Option<Marker>) -> CompletedMarker {
597 assert!(p.at(T![try]));
598 let m = m.unwrap_or_else(|| p.start());
599 // Special-case `try!` as macro.
600 // This is a hack until we do proper edition support
601 if p.nth_at(1, T![!]) {
602 // test try_macro_fallback
603 // fn foo() { try!(Ok(())); }
604 let path = p.start();
605 let path_segment = p.start();
606 let name_ref = p.start();
608 name_ref.complete(p, NAME_REF);
609 path_segment.complete(p, PATH_SEGMENT);
610 path.complete(p, PATH);
611 let _block_like = items::macro_call_after_excl(p);
612 return m.complete(p, MACRO_CALL);
619 p.error("expected a block");
621 m.complete(p, BLOCK_EXPR)
627 // let y = (box 1i32, box 2i32);
628 // let z = Foo(box 1i32, box 2i32);
630 fn box_expr(p: &mut Parser, m: Option<Marker>) -> CompletedMarker {
631 assert!(p.at(T![box]));
632 let m = m.unwrap_or_else(|| p.start());
634 if p.at_ts(EXPR_FIRST) {
637 m.complete(p, BOX_EXPR)