The given Uiua example (mercifully given using words rather than the symbols):

[3 4 5 10 23]
divide length on /+

For all the talk about “forward” it’s uncomfortable to me how the Uiua evaluation within a line happens backward.

An equivalent in Factor, where keep is close to on:

{ 3 4 5 10 23 }
[ sum ] keep length /

But this pattern of doing two things in sequence to the same item is common enough that bi is handy:

{ 3 4 5 10 23 }
[ sum ] [ length ] bi /