Comment by tmtvl
3 months ago
> Some Lisps may be able to do all this, although I don’t know if they quite do what I’m talking about here; I’m talking about there being a very distinct point where the programmer says “OK, I’m done being dynamic” for any given piece of code.
In Common Lisp there are tricks you can pull like declaring functions in a lexical scope (using labels or flet) to remove their lookup overhead. But CL is generally fast enough that it doesn't really matter much.
You can declaim inline a toplevel function. That doesn't necessarily mean that it will be integrated into callers. Among the possible effects is that the dynamism of reference can be culled away. If a function A calls B where B is declaimed inline then A can be compiled to assume that B definition. (Such that if B is redefined at run-time, A can keep calling the old B, not going through the #'B function binding lookup.).
I seem to remember that Common Lisp compilers are allowed to do this for functions that are in the same file even if they are not declaimed inline. If A and B are in the same file, and B is not declaimed notinline (the opposite of inline), then A can be translated to assume the B definition.
So all your helper functions in a Lisp module are allowed to be called more efficiently, not having to go through the function binding of the symbol.