From 5222b8aba3b1c2c68706aacf6869423a8e4fe6d5 Mon Sep 17 00:00:00 2001 From: Aleksey Kladov Date: Wed, 20 Feb 2019 15:47:32 +0300 Subject: move all parsing related bits to a separate module --- crates/ra_syntax/src/parsing/grammar/types.rs | 278 ++++++++++++++++++++++++++ 1 file changed, 278 insertions(+) create mode 100644 crates/ra_syntax/src/parsing/grammar/types.rs (limited to 'crates/ra_syntax/src/parsing/grammar/types.rs') diff --git a/crates/ra_syntax/src/parsing/grammar/types.rs b/crates/ra_syntax/src/parsing/grammar/types.rs new file mode 100644 index 000000000..adc189a29 --- /dev/null +++ b/crates/ra_syntax/src/parsing/grammar/types.rs @@ -0,0 +1,278 @@ +use super::*; + +pub(super) const TYPE_FIRST: TokenSet = paths::PATH_FIRST.union(token_set![ + L_PAREN, EXCL, STAR, L_BRACK, AMP, UNDERSCORE, FN_KW, UNSAFE_KW, EXTERN_KW, FOR_KW, IMPL_KW, + DYN_KW, L_ANGLE, +]); + +const TYPE_RECOVERY_SET: TokenSet = token_set![R_PAREN, COMMA]; + +pub(super) fn type_(p: &mut Parser) { + type_with_bounds_cond(p, true); +} + +pub(super) fn type_no_bounds(p: &mut Parser) { + type_with_bounds_cond(p, false); +} + +fn type_with_bounds_cond(p: &mut Parser, allow_bounds: bool) { + match p.current() { + L_PAREN => paren_or_tuple_type(p), + EXCL => never_type(p), + STAR => pointer_type(p), + L_BRACK => array_or_slice_type(p), + AMP => reference_type(p), + UNDERSCORE => placeholder_type(p), + FN_KW | UNSAFE_KW | EXTERN_KW => fn_pointer_type(p), + FOR_KW => for_type(p), + IMPL_KW => impl_trait_type(p), + DYN_KW => dyn_trait_type(p), + // Some path types are not allowed to have bounds (no plus) + L_ANGLE => path_type_(p, allow_bounds), + _ if paths::is_path_start(p) => path_or_macro_type_(p, allow_bounds), + _ => { + p.err_recover("expected type", TYPE_RECOVERY_SET); + } + } +} + +pub(super) fn ascription(p: &mut Parser) { + p.expect(COLON); + type_(p) +} + +fn paren_or_tuple_type(p: &mut Parser) { + assert!(p.at(L_PAREN)); + let m = p.start(); + p.bump(); + let mut n_types: u32 = 0; + let mut trailing_comma: bool = false; + while !p.at(EOF) && !p.at(R_PAREN) { + n_types += 1; + type_(p); + if p.eat(COMMA) { + trailing_comma = true; + } else { + trailing_comma = false; + break; + } + } + p.expect(R_PAREN); + + let kind = if n_types == 1 && !trailing_comma { + // test paren_type + // type T = (i32); + PAREN_TYPE + } else { + // test unit_type + // type T = (); + + // test singleton_tuple_type + // type T = (i32,); + TUPLE_TYPE + }; + m.complete(p, kind); +} + +// test never_type +// type Never = !; +fn never_type(p: &mut Parser) { + assert!(p.at(EXCL)); + let m = p.start(); + p.bump(); + m.complete(p, NEVER_TYPE); +} + +fn pointer_type(p: &mut Parser) { + assert!(p.at(STAR)); + let m = p.start(); + p.bump(); + + match p.current() { + // test pointer_type_mut + // type M = *mut (); + // type C = *mut (); + MUT_KW | CONST_KW => p.bump(), + _ => { + // test_err pointer_type_no_mutability + // type T = *(); + p.error( + "expected mut or const in raw pointer type \ + (use `*mut T` or `*const T` as appropriate)", + ); + } + }; + + type_no_bounds(p); + m.complete(p, POINTER_TYPE); +} + +fn array_or_slice_type(p: &mut Parser) { + assert!(p.at(L_BRACK)); + let m = p.start(); + p.bump(); + + type_(p); + let kind = match p.current() { + // test slice_type + // type T = [()]; + R_BRACK => { + p.bump(); + SLICE_TYPE + } + + // test array_type + // type T = [(); 92]; + SEMI => { + p.bump(); + expressions::expr(p); + p.expect(R_BRACK); + ARRAY_TYPE + } + // test_err array_type_missing_semi + // type T = [() 92]; + _ => { + p.error("expected `;` or `]`"); + SLICE_TYPE + } + }; + m.complete(p, kind); +} + +// test reference_type; +// type A = &(); +// type B = &'static (); +// type C = &mut (); +fn reference_type(p: &mut Parser) { + assert!(p.at(AMP)); + let m = p.start(); + p.bump(); + p.eat(LIFETIME); + p.eat(MUT_KW); + type_no_bounds(p); + m.complete(p, REFERENCE_TYPE); +} + +// test placeholder_type +// type Placeholder = _; +fn placeholder_type(p: &mut Parser) { + assert!(p.at(UNDERSCORE)); + let m = p.start(); + p.bump(); + m.complete(p, PLACEHOLDER_TYPE); +} + +// test fn_pointer_type +// type A = fn(); +// type B = unsafe fn(); +// type C = unsafe extern "C" fn(); +fn fn_pointer_type(p: &mut Parser) { + let m = p.start(); + p.eat(UNSAFE_KW); + if p.at(EXTERN_KW) { + abi(p); + } + // test_err fn_pointer_type_missing_fn + // type F = unsafe (); + if !p.eat(FN_KW) { + m.abandon(p); + p.error("expected `fn`"); + return; + } + if p.at(L_PAREN) { + params::param_list_opt_patterns(p); + } else { + p.error("expected parameters") + } + // test fn_pointer_type_with_ret + // type F = fn() -> (); + opt_fn_ret_type(p); + m.complete(p, FN_POINTER_TYPE); +} + +pub(super) fn for_binder(p: &mut Parser) { + assert!(p.at(FOR_KW)); + p.bump(); + if p.at(L_ANGLE) { + type_params::opt_type_param_list(p); + } else { + p.error("expected `<`"); + } +} + +// test for_type +// type A = for<'a> fn() -> (); +pub(super) fn for_type(p: &mut Parser) { + assert!(p.at(FOR_KW)); + let m = p.start(); + for_binder(p); + match p.current() { + FN_KW | UNSAFE_KW | EXTERN_KW => fn_pointer_type(p), + _ if paths::is_path_start(p) => path_type_(p, false), + _ => p.error("expected a path"), + } + m.complete(p, FOR_TYPE); +} + +// test impl_trait_type +// type A = impl Iterator> + 'a; +fn impl_trait_type(p: &mut Parser) { + assert!(p.at(IMPL_KW)); + let m = p.start(); + p.bump(); + type_params::bounds_without_colon(p); + m.complete(p, IMPL_TRAIT_TYPE); +} + +// test dyn_trait_type +// type A = dyn Iterator> + 'a; +fn dyn_trait_type(p: &mut Parser) { + assert!(p.at(DYN_KW)); + let m = p.start(); + p.bump(); + type_params::bounds_without_colon(p); + m.complete(p, DYN_TRAIT_TYPE); +} + +// test path_type +// type A = Foo; +// type B = ::Foo; +// type C = self::Foo; +// type D = super::Foo; +pub(super) fn path_type(p: &mut Parser) { + path_type_(p, true) +} + +// test macro_call_type +// type A = foo!(); +// type B = crate::foo!(); +fn path_or_macro_type_(p: &mut Parser, allow_bounds: bool) { + assert!(paths::is_path_start(p) || p.at(L_ANGLE)); + let m = p.start(); + paths::type_path(p); + + let kind = if p.at(EXCL) { + items::macro_call_after_excl(p); + MACRO_CALL + } else { + PATH_TYPE + }; + + if allow_bounds && p.eat(PLUS) { + type_params::bounds_without_colon(p); + } + + m.complete(p, kind); +} + +pub(super) fn path_type_(p: &mut Parser, allow_bounds: bool) { + assert!(paths::is_path_start(p) || p.at(L_ANGLE)); + let m = p.start(); + paths::type_path(p); + // test path_type_with_bounds + // fn foo() -> Box {} + if allow_bounds && p.eat(PLUS) { + type_params::bounds_without_colon(p); + } + m.complete(p, PATH_TYPE); +} -- cgit v1.2.3