Grade-based UniqueMask implementation

1 files changed, 2 insertions, 2 deletions

diff --git a/src/r.bqn b/src/r.bqn
index 9afb02bf..e927c8a3 100644
--- a/src/r.bqn
+++ b/src/r.bqn
@@ -342,8 +342,8 @@ IndexOf←{
 }
 UniqueMask←{
   ! 1≤=𝕩
-  u←0↑𝕩
-  {(≠u)>0⊑⥊u IndexOf 𝕩}◶{u↩u∾𝕩⋄1}‿0˘𝕩
+  g←Cmp _grade 𝕩
+  (1¨⊸GroupOrd g)⊏0⊸<◶⟨1,-⟜1≢○(⊑⟜(g⊏<˘⍟(1<=)𝕩))⊢⟩⌜↕≠𝕩
 }
 Find←{
   r←=𝕨