Re: [stack] Jon Purdy: Why Concatenative Programming Matters

This commentor appropriately acknowledges the important cognitive-load aspect:-
]the code was always *intensely* write-only since you had to have a
]mental model of exactly what was on the stack where to even hope to
]follow it.

*nix piping is beautifully simple yet powerfull, since the stack only contains
"it" [the previous output]. So that at each/every stage, you only need to know
about your single-supplier.

]     2 :: FAA. (A) -> (A, int)
]     3 :: FAB. (B) -> (B, int)
ok

]   We match up the types:
]
]     (A, int) = (B)

?! does this mean 'assume they match and see what that implies'?
-------------
Apparently, if the output of stageN includes item/s in addition to what
stageN+1 needs, they can be left on the stack for stageN+2. But he and
Haskell/monads seems to 'wrap' the extra item/s and pass it on, and
imply that some automagic relieves you from the mental load of
remembering what was left on the stack for all possible
combinations of stages afterN+1 ?