minor: reduce duplication

Author: matklad

crates/parser/src/grammar/generic_args.rs

@@ -26,15 +26,16 @@ pub(super) fn opt_generic_arg_list(p: &mut Parser, colon_colon_required: bool) {
 // test type_arg
 // type A = B<'static, i32, 1, { 2 }, Item=u64, true, false>;
 fn generic_arg(p: &mut Parser) {
-    let m = p.start();
     match p.current() {
         LIFETIME_IDENT => {
+            let m = p.start();
             lifetime(p);
             m.complete(p, LIFETIME_ARG);
         }
         // test associated_type_bounds
         // fn print_all<T: Iterator<Item, Item::Item, Item::<true>, Item: Display, Item<'a> = Item>>(printables: T) {}
         IDENT if [T![<], T![=], T![:]].contains(&p.nth(1)) => {
+            let m = p.start();
             let path_ty = p.start();
             let path = p.start();
             let path_seg = p.start();
@@ -78,28 +79,12 @@ fn generic_arg(p: &mut Parser) {
                 }
             }
         }
-        T!['{'] => {
-            expressions::block_expr(p);
-            m.complete(p, CONST_ARG);
-        }
-        k if k.is_literal() => {
-            expressions::literal(p);
-            m.complete(p, CONST_ARG);
-        }
-        T![true] | T![false] => {
-            expressions::literal(p);
-            m.complete(p, CONST_ARG);
-        }
         // test const_generic_negated_literal
         // fn f() { S::<-1> }
-        T![-] => {
-            let lm = p.start();
-            p.bump(T![-]);
-            expressions::literal(p);
-            lm.complete(p, PREFIX_EXPR);
-            m.complete(p, CONST_ARG);
-        }
+        T!['{'] | T![true] | T![false] | T![-] => const_arg(p),
+        k if k.is_literal() => const_arg(p),
         _ => {
+            let m = p.start();
             types::type_(p);
             m.complete(p, TYPE_ARG);
         }
@@ -108,7 +93,6 @@ fn generic_arg(p: &mut Parser) {
 
 pub(super) fn const_arg(p: &mut Parser) {
     let m = p.start();
-    // FIXME: duplicates the code above
     match p.current() {
         T!['{'] => {
             expressions::block_expr(p);