From d334b5a1db9ec6a57f54077d422a3f4b3c8c1178 Mon Sep 17 00:00:00 2001 From: Aleksey Kladov Date: Thu, 21 Feb 2019 13:27:45 +0300 Subject: move parser to a separate crate --- crates/ra_parser/src/grammar/expressions/atom.rs | 475 +++++++++++++++++++++++ 1 file changed, 475 insertions(+) create mode 100644 crates/ra_parser/src/grammar/expressions/atom.rs (limited to 'crates/ra_parser/src/grammar/expressions') diff --git a/crates/ra_parser/src/grammar/expressions/atom.rs b/crates/ra_parser/src/grammar/expressions/atom.rs new file mode 100644 index 000000000..e74305b6a --- /dev/null +++ b/crates/ra_parser/src/grammar/expressions/atom.rs @@ -0,0 +1,475 @@ +use super::*; + +// test expr_literals +// fn foo() { +// let _ = true; +// let _ = false; +// let _ = 1; +// let _ = 2.0; +// let _ = b'a'; +// let _ = 'b'; +// let _ = "c"; +// let _ = r"d"; +// let _ = b"e"; +// let _ = br"f"; +// } +pub(crate) const LITERAL_FIRST: TokenSet = token_set![ + TRUE_KW, + FALSE_KW, + INT_NUMBER, + FLOAT_NUMBER, + BYTE, + CHAR, + STRING, + RAW_STRING, + BYTE_STRING, + RAW_BYTE_STRING +]; + +pub(crate) fn literal(p: &mut Parser) -> Option { + if !p.at_ts(LITERAL_FIRST) { + return None; + } + let m = p.start(); + p.bump(); + Some(m.complete(p, LITERAL)) +} + +// E.g. for after the break in `if break {}`, this should not match +pub(super) const ATOM_EXPR_FIRST: TokenSet = + LITERAL_FIRST.union(paths::PATH_FIRST).union(token_set![ + L_PAREN, + L_CURLY, + L_BRACK, + PIPE, + MOVE_KW, + IF_KW, + WHILE_KW, + MATCH_KW, + UNSAFE_KW, + RETURN_KW, + BREAK_KW, + CONTINUE_KW, + LIFETIME, + ]); + +const EXPR_RECOVERY_SET: TokenSet = token_set![LET_KW]; + +pub(super) fn atom_expr(p: &mut Parser, r: Restrictions) -> Option<(CompletedMarker, BlockLike)> { + if let Some(m) = literal(p) { + return Some((m, BlockLike::NotBlock)); + } + if paths::is_path_start(p) || p.at(L_ANGLE) { + return Some(path_expr(p, r)); + } + let la = p.nth(1); + let done = match p.current() { + L_PAREN => tuple_expr(p), + L_BRACK => array_expr(p), + PIPE => lambda_expr(p), + MOVE_KW if la == PIPE => lambda_expr(p), + IF_KW => if_expr(p), + + LOOP_KW => loop_expr(p, None), + FOR_KW => for_expr(p, None), + WHILE_KW => while_expr(p, None), + LIFETIME if la == COLON => { + let m = p.start(); + label(p); + match p.current() { + LOOP_KW => loop_expr(p, Some(m)), + FOR_KW => for_expr(p, Some(m)), + WHILE_KW => while_expr(p, Some(m)), + L_CURLY => block_expr(p, Some(m)), + _ => { + // test_err misplaced_label_err + // fn main() { + // 'loop: impl + // } + p.error("expected a loop"); + m.complete(p, ERROR); + return None; + } + } + } + + MATCH_KW => match_expr(p), + UNSAFE_KW if la == L_CURLY => { + let m = p.start(); + p.bump(); + block_expr(p, Some(m)) + } + L_CURLY => block_expr(p, None), + RETURN_KW => return_expr(p), + CONTINUE_KW => continue_expr(p), + BREAK_KW => break_expr(p, r), + _ => { + p.err_recover("expected expression", EXPR_RECOVERY_SET); + return None; + } + }; + let blocklike = match done.kind() { + IF_EXPR | WHILE_EXPR | FOR_EXPR | LOOP_EXPR | MATCH_EXPR | BLOCK_EXPR => BlockLike::Block, + _ => BlockLike::NotBlock, + }; + Some((done, blocklike)) +} + +// test tuple_expr +// fn foo() { +// (); +// (1); +// (1,); +// } +fn tuple_expr(p: &mut Parser) -> CompletedMarker { + assert!(p.at(L_PAREN)); + let m = p.start(); + p.expect(L_PAREN); + + let mut saw_comma = false; + let mut saw_expr = false; + while !p.at(EOF) && !p.at(R_PAREN) { + saw_expr = true; + if !p.at_ts(EXPR_FIRST) { + p.error("expected expression"); + break; + } + expr(p); + if !p.at(R_PAREN) { + saw_comma = true; + p.expect(COMMA); + } + } + p.expect(R_PAREN); + m.complete(p, if saw_expr && !saw_comma { PAREN_EXPR } else { TUPLE_EXPR }) +} + +// test array_expr +// fn foo() { +// []; +// [1]; +// [1, 2,]; +// [1; 2]; +// } +fn array_expr(p: &mut Parser) -> CompletedMarker { + assert!(p.at(L_BRACK)); + let m = p.start(); + p.bump(); + if p.eat(R_BRACK) { + return m.complete(p, ARRAY_EXPR); + } + expr(p); + if p.eat(SEMI) { + expr(p); + p.expect(R_BRACK); + return m.complete(p, ARRAY_EXPR); + } + while !p.at(EOF) && !p.at(R_BRACK) { + p.expect(COMMA); + if p.at(R_BRACK) { + break; + } + if !p.at_ts(EXPR_FIRST) { + p.error("expected expression"); + break; + } + expr(p); + } + p.expect(R_BRACK); + m.complete(p, ARRAY_EXPR) +} + +// test lambda_expr +// fn foo() { +// || (); +// || -> i32 { 92 }; +// |x| x; +// move |x: i32,| x; +// } +fn lambda_expr(p: &mut Parser) -> CompletedMarker { + assert!(p.at(PIPE) || (p.at(MOVE_KW) && p.nth(1) == PIPE)); + let m = p.start(); + p.eat(MOVE_KW); + params::param_list_opt_types(p); + if opt_fn_ret_type(p) { + if !p.at(L_CURLY) { + p.error("expected `{`"); + } + } + expr(p); + m.complete(p, LAMBDA_EXPR) +} + +// test if_expr +// fn foo() { +// if true {}; +// if true {} else {}; +// if true {} else if false {} else {}; +// if S {}; +// } +fn if_expr(p: &mut Parser) -> CompletedMarker { + assert!(p.at(IF_KW)); + let m = p.start(); + p.bump(); + cond(p); + block(p); + if p.at(ELSE_KW) { + p.bump(); + if p.at(IF_KW) { + if_expr(p); + } else { + block(p); + } + } + m.complete(p, IF_EXPR) +} + +// test label +// fn foo() { +// 'a: loop {} +// 'b: while true {} +// 'c: for x in () {} +// } +fn label(p: &mut Parser) { + assert!(p.at(LIFETIME) && p.nth(1) == COLON); + let m = p.start(); + p.bump(); + p.bump(); + m.complete(p, LABEL); +} + +// test loop_expr +// fn foo() { +// loop {}; +// } +fn loop_expr(p: &mut Parser, m: Option) -> CompletedMarker { + assert!(p.at(LOOP_KW)); + let m = m.unwrap_or_else(|| p.start()); + p.bump(); + block(p); + m.complete(p, LOOP_EXPR) +} + +// test while_expr +// fn foo() { +// while true {}; +// while let Some(x) = it.next() {}; +// } +fn while_expr(p: &mut Parser, m: Option) -> CompletedMarker { + assert!(p.at(WHILE_KW)); + let m = m.unwrap_or_else(|| p.start()); + p.bump(); + cond(p); + block(p); + m.complete(p, WHILE_EXPR) +} + +// test for_expr +// fn foo() { +// for x in [] {}; +// } +fn for_expr(p: &mut Parser, m: Option) -> CompletedMarker { + assert!(p.at(FOR_KW)); + let m = m.unwrap_or_else(|| p.start()); + p.bump(); + patterns::pattern(p); + p.expect(IN_KW); + expr_no_struct(p); + block(p); + m.complete(p, FOR_EXPR) +} + +// test cond +// fn foo() { if let Some(_) = None {} } +fn cond(p: &mut Parser) { + let m = p.start(); + if p.eat(LET_KW) { + patterns::pattern(p); + p.expect(EQ); + } + expr_no_struct(p); + m.complete(p, CONDITION); +} + +// test match_expr +// fn foo() { +// match () { }; +// match S {}; +// } +fn match_expr(p: &mut Parser) -> CompletedMarker { + assert!(p.at(MATCH_KW)); + let m = p.start(); + p.bump(); + expr_no_struct(p); + if p.at(L_CURLY) { + match_arm_list(p); + } else { + p.error("expected `{`") + } + m.complete(p, MATCH_EXPR) +} + +pub(crate) fn match_arm_list(p: &mut Parser) { + assert!(p.at(L_CURLY)); + let m = p.start(); + p.eat(L_CURLY); + + // test match_arms_inner_attribute + // fn foo() { + // match () { + // #![doc("Inner attribute")] + // #![doc("Can be")] + // #![doc("Stacked")] + // _ => (), + // } + // } + attributes::inner_attributes(p); + + while !p.at(EOF) && !p.at(R_CURLY) { + if p.at(L_CURLY) { + error_block(p, "expected match arm"); + continue; + } + + // test match_arms_outer_attributes + // fn foo() { + // match () { + // #[cfg(feature = "some")] + // _ => (), + // #[cfg(feature = "other")] + // _ => (), + // #[cfg(feature = "many")] + // #[cfg(feature = "attributes")] + // #[cfg(feature = "before")] + // _ => (), + // } + // } + attributes::outer_attributes(p); + + // test match_arms_commas + // fn foo() { + // match () { + // _ => (), + // _ => {} + // _ => () + // } + // } + if match_arm(p).is_block() { + p.eat(COMMA); + } else if !p.at(R_CURLY) { + p.expect(COMMA); + } + } + p.expect(R_CURLY); + m.complete(p, MATCH_ARM_LIST); +} + +// test match_arm +// fn foo() { +// match () { +// _ => (), +// _ if Test > Test{field: 0} => (), +// X | Y if Z => (), +// | X | Y if Z => (), +// | X => (), +// }; +// } +fn match_arm(p: &mut Parser) -> BlockLike { + let m = p.start(); + p.eat(PIPE); + patterns::pattern_r(p, TokenSet::empty()); + while p.eat(PIPE) { + patterns::pattern(p); + } + if p.at(IF_KW) { + match_guard(p); + } + p.expect(FAT_ARROW); + let ret = expr_stmt(p); + m.complete(p, MATCH_ARM); + ret +} + +// test match_guard +// fn foo() { +// match () { +// _ if foo => (), +// } +// } +fn match_guard(p: &mut Parser) -> CompletedMarker { + assert!(p.at(IF_KW)); + let m = p.start(); + p.bump(); + expr(p); + m.complete(p, MATCH_GUARD) +} + +// test block_expr +// fn foo() { +// {}; +// unsafe {}; +// 'label: {}; +// } +fn block_expr(p: &mut Parser, m: Option) -> CompletedMarker { + assert!(p.at(L_CURLY)); + let m = m.unwrap_or_else(|| p.start()); + block(p); + m.complete(p, BLOCK_EXPR) +} + +// test return_expr +// fn foo() { +// return; +// return 92; +// } +fn return_expr(p: &mut Parser) -> CompletedMarker { + assert!(p.at(RETURN_KW)); + let m = p.start(); + p.bump(); + if p.at_ts(EXPR_FIRST) { + expr(p); + } + m.complete(p, RETURN_EXPR) +} + +// test continue_expr +// fn foo() { +// loop { +// continue; +// continue 'l; +// } +// } +fn continue_expr(p: &mut Parser) -> CompletedMarker { + assert!(p.at(CONTINUE_KW)); + let m = p.start(); + p.bump(); + p.eat(LIFETIME); + m.complete(p, CONTINUE_EXPR) +} + +// test break_expr +// fn foo() { +// loop { +// break; +// break 'l; +// break 92; +// break 'l 92; +// } +// } +fn break_expr(p: &mut Parser, r: Restrictions) -> CompletedMarker { + assert!(p.at(BREAK_KW)); + let m = p.start(); + p.bump(); + p.eat(LIFETIME); + // test break_ambiguity + // fn foo(){ + // if break {} + // while break {} + // for i in break {} + // match break {} + // } + if p.at_ts(EXPR_FIRST) && !(r.forbid_structs && p.at(L_CURLY)) { + expr(p); + } + m.complete(p, BREAK_EXPR) +} -- cgit v1.2.3