1 files changed, 48 insertions, 0 deletions

diff --git a/crates/parser/src/grammar/attributes.rs b/crates/parser/src/grammar/attributes.rs
new file mode 100644
index 000000000..f3158ade3
--- /dev/null
+++ b/crates/parser/src/grammar/attributes.rs
@@ -0,0 +1,48 @@
+//! FIXME: write short doc here
+
+use super::*;
+
+pub(super) fn inner_attributes(p: &mut Parser) {
+    while p.at(T![#]) && p.nth(1) == T![!] {
+        attribute(p, true)
+    }
+}
+
+pub(super) fn outer_attributes(p: &mut Parser) {
+    while p.at(T![#]) {
+        attribute(p, false)
+    }
+}
+
+fn attribute(p: &mut Parser, inner: bool) {
+    let attr = p.start();
+    assert!(p.at(T![#]));
+    p.bump(T![#]);
+
+    if inner {
+        assert!(p.at(T![!]));
+        p.bump(T![!]);
+    }
+
+    if p.eat(T!['[']) {
+        paths::use_path(p);
+
+        match p.current() {
+            T![=] => {
+                p.bump(T![=]);
+                if expressions::literal(p).is_none() {
+                    p.error("expected literal");
+                }
+            }
+            T!['('] | T!['['] | T!['{'] => items::token_tree(p),
+            _ => {}
+        }
+
+        if !p.eat(T![']']) {
+            p.error("expected `]`");
+        }
+    } else {
+        p.error("expected `[`");
+    }
+    attr.complete(p, ATTR);
+}