Allow value omission in Hash literals

`{x:, y:}` is a syntax sugar of `{x: x, y: y}`.

1 files changed, 9 insertions, 0 deletions

diff --git a/parse.y b/parse.y
index 8017011bb7..d4443d50d2 100644
--- a/parse.y
+++ b/parse.y
@@ -5617,6 +5617,15 @@ assoc		: arg_value tASSOC arg_value
 		    /*% %*/
 		    /*% ripper: assoc_new!($1, $2) %*/
 		    }
+		| tLABEL
+		    {
+		    /*%%%*/
+			NODE *val = gettable(p, $1, &@$);
+			if (!val) val = NEW_BEGIN(0, &@$);
+			$$ = list_append(p, NEW_LIST(NEW_LIT(ID2SYM($1), &@1), &@$), val);
+		    /*% %*/
+		    /*% ripper: assoc_new!($1, id_is_var(p, get_id($1)) ? var_ref!($1) : vcall!($1)) %*/
+		    }
 		| tSTRING_BEG string_contents tLABEL_END arg_value
 		    {
 		    /*%%%*/