Designing Code For Forward Progress

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

 undefined

        [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:

 undefined

        { 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:

 undefined

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