From 50a02eb3593591a02677e1b56f24d7ff0459b9d0 Mon Sep 17 00:00:00 2001 From: Aleksey Kladov Date: Wed, 12 Aug 2020 17:06:49 +0200 Subject: Rename ra_parser -> parser --- crates/parser/src/grammar/patterns.rs | 379 ++++++++++++++++++++++++++++++++++ 1 file changed, 379 insertions(+) create mode 100644 crates/parser/src/grammar/patterns.rs (limited to 'crates/parser/src/grammar/patterns.rs') diff --git a/crates/parser/src/grammar/patterns.rs b/crates/parser/src/grammar/patterns.rs new file mode 100644 index 000000000..716bdc978 --- /dev/null +++ b/crates/parser/src/grammar/patterns.rs @@ -0,0 +1,379 @@ +//! FIXME: write short doc here + +use super::*; + +pub(super) const PATTERN_FIRST: TokenSet = expressions::LITERAL_FIRST + .union(paths::PATH_FIRST) + .union(token_set![T![box], T![ref], T![mut], T!['('], T!['['], T![&], T![_], T![-], T![.]]); + +pub(crate) fn pattern(p: &mut Parser) { + pattern_r(p, PAT_RECOVERY_SET); +} + +/// Parses a pattern list separated by pipes `|` +pub(super) fn pattern_top(p: &mut Parser) { + pattern_top_r(p, PAT_RECOVERY_SET) +} + +pub(crate) fn pattern_single(p: &mut Parser) { + pattern_single_r(p, PAT_RECOVERY_SET); +} + +/// Parses a pattern list separated by pipes `|` +/// using the given `recovery_set` +pub(super) fn pattern_top_r(p: &mut Parser, recovery_set: TokenSet) { + p.eat(T![|]); + pattern_r(p, recovery_set); +} + +/// Parses a pattern list separated by pipes `|`, with no leading `|`,using the +/// given `recovery_set` +// test or_pattern +// fn main() { +// match () { +// (_ | _) => (), +// &(_ | _) => (), +// (_ | _,) => (), +// [_ | _,] => (), +// } +// } +fn pattern_r(p: &mut Parser, recovery_set: TokenSet) { + let m = p.start(); + pattern_single_r(p, recovery_set); + + if !p.at(T![|]) { + m.abandon(p); + return; + } + while p.eat(T![|]) { + pattern_single_r(p, recovery_set); + } + m.complete(p, OR_PAT); +} + +fn pattern_single_r(p: &mut Parser, recovery_set: TokenSet) { + if let Some(lhs) = atom_pat(p, recovery_set) { + // test range_pat + // fn main() { + // match 92 { + // 0 ... 100 => (), + // 101 ..= 200 => (), + // 200 .. 301=> (), + // } + // } + for &range_op in [T![...], T![..=], T![..]].iter() { + if p.at(range_op) { + let m = lhs.precede(p); + p.bump(range_op); + atom_pat(p, recovery_set); + m.complete(p, RANGE_PAT); + return; + } + } + } +} + +const PAT_RECOVERY_SET: TokenSet = + token_set![LET_KW, IF_KW, WHILE_KW, LOOP_KW, MATCH_KW, R_PAREN, COMMA]; + +fn atom_pat(p: &mut Parser, recovery_set: TokenSet) -> Option { + let m = match p.nth(0) { + T![box] => box_pat(p), + T![ref] | T![mut] => bind_pat(p, true), + IDENT => match p.nth(1) { + // Checks the token after an IDENT to see if a pattern is a path (Struct { .. }) or macro + // (T![x]). + T!['('] | T!['{'] | T![!] => path_or_macro_pat(p), + T![:] if p.nth_at(1, T![::]) => path_or_macro_pat(p), + _ => bind_pat(p, true), + }, + + // test type_path_in_pattern + // fn main() { let <_>::Foo = (); } + _ if paths::is_path_start(p) => path_or_macro_pat(p), + _ if is_literal_pat_start(p) => literal_pat(p), + + T![.] if p.at(T![..]) => dot_dot_pat(p), + T![_] => placeholder_pat(p), + T![&] => ref_pat(p), + T!['('] => tuple_pat(p), + T!['['] => slice_pat(p), + + _ => { + p.err_recover("expected pattern", recovery_set); + return None; + } + }; + + Some(m) +} + +fn is_literal_pat_start(p: &Parser) -> bool { + p.at(T![-]) && (p.nth(1) == INT_NUMBER || p.nth(1) == FLOAT_NUMBER) + || p.at_ts(expressions::LITERAL_FIRST) +} + +// test literal_pattern +// fn main() { +// match () { +// -1 => (), +// 92 => (), +// 'c' => (), +// "hello" => (), +// } +// } +fn literal_pat(p: &mut Parser) -> CompletedMarker { + assert!(is_literal_pat_start(p)); + let m = p.start(); + if p.at(T![-]) { + p.bump(T![-]); + } + expressions::literal(p); + m.complete(p, LITERAL_PAT) +} + +// test path_part +// fn foo() { +// let foo::Bar = (); +// let ::Bar = (); +// let Bar { .. } = (); +// let Bar(..) = (); +// } +fn path_or_macro_pat(p: &mut Parser) -> CompletedMarker { + assert!(paths::is_path_start(p)); + let m = p.start(); + paths::expr_path(p); + let kind = match p.current() { + T!['('] => { + tuple_pat_fields(p); + TUPLE_STRUCT_PAT + } + T!['{'] => { + record_field_pat_list(p); + RECORD_PAT + } + // test marco_pat + // fn main() { + // let m!(x) = 0; + // } + T![!] => { + items::macro_call_after_excl(p); + return m.complete(p, MACRO_CALL).precede(p).complete(p, MACRO_PAT); + } + _ => PATH_PAT, + }; + m.complete(p, kind) +} + +// test tuple_pat_fields +// fn foo() { +// let S() = (); +// let S(_) = (); +// let S(_,) = (); +// let S(_, .. , x) = (); +// } +fn tuple_pat_fields(p: &mut Parser) { + assert!(p.at(T!['('])); + p.bump(T!['(']); + pat_list(p, T![')']); + p.expect(T![')']); +} + +// test record_field_pat_list +// fn foo() { +// let S {} = (); +// let S { f, ref mut g } = (); +// let S { h: _, ..} = (); +// let S { h: _, } = (); +// } +fn record_field_pat_list(p: &mut Parser) { + assert!(p.at(T!['{'])); + let m = p.start(); + p.bump(T!['{']); + while !p.at(EOF) && !p.at(T!['}']) { + match p.current() { + // A trailing `..` is *not* treated as a REST_PAT. + T![.] if p.at(T![..]) => p.bump(T![..]), + T!['{'] => error_block(p, "expected ident"), + + c => { + let m = p.start(); + match c { + // test record_field_pat + // fn foo() { + // let S { 0: 1 } = (); + // let S { x: 1 } = (); + // } + IDENT | INT_NUMBER if p.nth(1) == T![:] => { + name_ref_or_index(p); + p.bump(T![:]); + pattern(p); + } + T![box] => { + // FIXME: not all box patterns should be allowed + box_pat(p); + } + _ => { + bind_pat(p, false); + } + } + m.complete(p, RECORD_PAT_FIELD); + } + } + if !p.at(T!['}']) { + p.expect(T![,]); + } + } + p.expect(T!['}']); + m.complete(p, RECORD_PAT_FIELD_LIST); +} + +// test placeholder_pat +// fn main() { let _ = (); } +fn placeholder_pat(p: &mut Parser) -> CompletedMarker { + assert!(p.at(T![_])); + let m = p.start(); + p.bump(T![_]); + m.complete(p, WILDCARD_PAT) +} + +// test dot_dot_pat +// fn main() { +// let .. = (); +// // +// // Tuples +// // +// let (a, ..) = (); +// let (a, ..,) = (); +// let Tuple(a, ..) = (); +// let Tuple(a, ..,) = (); +// let (.., ..) = (); +// let Tuple(.., ..) = (); +// let (.., a, ..) = (); +// let Tuple(.., a, ..) = (); +// // +// // Slices +// // +// let [..] = (); +// let [head, ..] = (); +// let [head, tail @ ..] = (); +// let [head, .., cons] = (); +// let [head, mid @ .., cons] = (); +// let [head, .., .., cons] = (); +// let [head, .., mid, tail @ ..] = (); +// let [head, .., mid, .., cons] = (); +// } +fn dot_dot_pat(p: &mut Parser) -> CompletedMarker { + assert!(p.at(T![..])); + let m = p.start(); + p.bump(T![..]); + m.complete(p, REST_PAT) +} + +// test ref_pat +// fn main() { +// let &a = (); +// let &mut b = (); +// } +fn ref_pat(p: &mut Parser) -> CompletedMarker { + assert!(p.at(T![&])); + let m = p.start(); + p.bump(T![&]); + p.eat(T![mut]); + pattern_single(p); + m.complete(p, REF_PAT) +} + +// test tuple_pat +// fn main() { +// let (a, b, ..) = (); +// let (a,) = (); +// let (..) = (); +// let () = (); +// } +fn tuple_pat(p: &mut Parser) -> CompletedMarker { + assert!(p.at(T!['('])); + let m = p.start(); + p.bump(T!['(']); + let mut has_comma = false; + let mut has_pat = false; + let mut has_rest = false; + while !p.at(EOF) && !p.at(T![')']) { + has_pat = true; + if !p.at_ts(PATTERN_FIRST) { + p.error("expected a pattern"); + break; + } + has_rest |= p.at(T![..]); + + pattern(p); + if !p.at(T![')']) { + has_comma = true; + p.expect(T![,]); + } + } + p.expect(T![')']); + + m.complete(p, if !has_comma && !has_rest && has_pat { PAREN_PAT } else { TUPLE_PAT }) +} + +// test slice_pat +// fn main() { +// let [a, b, ..] = []; +// } +fn slice_pat(p: &mut Parser) -> CompletedMarker { + assert!(p.at(T!['['])); + let m = p.start(); + p.bump(T!['[']); + pat_list(p, T![']']); + p.expect(T![']']); + m.complete(p, SLICE_PAT) +} + +fn pat_list(p: &mut Parser, ket: SyntaxKind) { + while !p.at(EOF) && !p.at(ket) { + if !p.at_ts(PATTERN_FIRST) { + p.error("expected a pattern"); + break; + } + + pattern(p); + if !p.at(ket) { + p.expect(T![,]); + } + } +} + +// test bind_pat +// fn main() { +// let a = (); +// let mut b = (); +// let ref c = (); +// let ref mut d = (); +// let e @ _ = (); +// let ref mut f @ g @ _ = (); +// } +fn bind_pat(p: &mut Parser, with_at: bool) -> CompletedMarker { + let m = p.start(); + p.eat(T![ref]); + p.eat(T![mut]); + name(p); + if with_at && p.eat(T![@]) { + pattern_single(p); + } + m.complete(p, IDENT_PAT) +} + +// test box_pat +// fn main() { +// let box i = (); +// let box Outer { box i, j: box Inner(box &x) } = (); +// let box ref mut i = (); +// } +fn box_pat(p: &mut Parser) -> CompletedMarker { + assert!(p.at(T![box])); + let m = p.start(); + p.bump(T![box]); + pattern_single(p); + m.complete(p, BOX_PAT) +} -- cgit v1.2.3