more compiler fixes

src/FWL/Parser.hs

@@ -225,7 +225,12 @@ arm = do
 -- ─── Patterns ────────────────────────────────────────────────────────────────
 
 pat :: Parser Pat
-pat =  wildcardPat
+pat = Ex.buildExpressionParser patTable patAtom <?> "pattern"
+  where
+    patTable = [ [Ex.Infix (reservedOp "|" >> return POr) Ex.AssocLeft] ]
+
+patAtom :: Parser Pat
+patAtom =  wildcardPat
    <|> try framePat
    <|> try tuplePat
    <|> bytesPat