[tempguy9999]

Could you elaborate? A bit searching throws up some very interesting stuff but AFAICS a transducer is roughly comparable to a partial function, which doesn't relate to my request for manual expression manipulation support.

If I'm missing something, please say.

[wvlia5]

I'm referring to transducers as in clojure. You can compose 2 'map' transducers, and that results in a single 'map' of the composed mapping-functions. That's to say that the two expressions you wrote would result in the same computations if you expressed them in terms of transducers.

[tempguy9999]

5 mins looking at https://stackoverflow.com/questions/26317325/can-someone-exp... I think I'm getting it. Ops accumulated and composed until they actually have to be evaluated. That's very interesting indeed, thanks, and I'll spend a couple of hours on it.

However, I was using my my example exactly as an example; I was after a symbolic manips app.

The issue of the cost of naively compiled functional languages matters to me as bad performance will kill a good thing.