works for dates and categorical input, not vector of strings

src/pipeline.jl

@@ -68,6 +68,17 @@ end
 function _preprocess_userrecipe(kw::AKW)
     _add_markershape(kw)
 
+    if get(kw,:series_permutation, default(:series_permutation)) != :none
+        l1, l2 = kw[:series_permutation]
+        for k in _axis_args
+            k1 = _attrsymbolcache[l1][k]
+            k2 = _attrsymbolcache[l2][k]
+            kwk = keys(kw)
+            if k1 in kwk || k2 in kwk
+                kw[k1], kw[k2] = get(kw, k2, default(k2)), get(kw, k1, default(k1))
+            end
+        end
+    end
     # map marker_z if it's a Function
     if isa(get(kw, :marker_z, default(:marker_z)), Function)
         # TODO: should this take y and/or z as arguments?