> wonder if it would be possible to do automated rewrites of recursive functions as iterative ones. specifically for cases where stack memory that grows in a re

> wonder if it would be possible to do automated rewrites of recursive functions as iterative ones. specifically for cases where stack memory that grows in a recursive implementation can be replaced by a few long lived temporaries. Yes. Some Lisp implementations do this automatically. See https://en.wikipedia.org/wiki/Continuation-passing_style https://en.wikipedia.org/wiki/Continuation-passing_style . Note that this differs from the POC of OP in that in OP's POC, only one function is defined, and it is transformed into a tree with if-statements to determine where in the code execution should be resumed, but in CPS it's an anonymous function in the tail being called with all context still relevant to it. Then the tail-call can be optimized out. Note that anonymous functions can be seen as just regular top-level functions with a hidden parameter containing the context relevant to it.