The idea is: one may want to eliminate use of the
Python language call-stack in the case of a “tail calls” (a function call where the result is not used by the calling function, but instead immediately returned). Tail call elimination can both speed up programs, and cut down on the overhead of maintaining intermediate stack frames and environments that will never be used again.
The note correctly points out that
Python purposely does not have a
goto statement, a tool one might use to implement true tail call elimination. So Kyle Miller built up a data-structure based replacement for the call stack, which allows one to work around the stack-limit for a specific function (without changing any
Python configuration, and without changing the behavior of other functions).
Python does have some exotic control-flow controls:
yield. So I decided to build an
exception based solution of our own using
Please read on for how we do this, and for some examples.