1 files changed, 278 insertions, 0 deletions

diff --git a/crates/ra_parser/src/grammar/types.rs b/crates/ra_parser/src/grammar/types.rs
new file mode 100644
index 000000000..adc189a29
--- /dev/null
+++ b/crates/ra_parser/src/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<Item=Foo<'a>> + '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<Item=Foo<'a>> + '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<T + 'f> {}
+    if allow_bounds && p.eat(PLUS) {
+        type_params::bounds_without_colon(p);
+    }
+    m.complete(p, PATH_TYPE);
+}