Tyler Jameson Little:
D could use something like Newsqueak's become keyword. If
you're not familial with Newsqueak, become is just like a
return, except it replaces the stack frame with the function
that it calls.
Are you talking about CPS?
http://en.wikipedia.org/wiki/Continuation_passing_style
DMD should optimize this already, but explicitly stating become
is a key to the compiler that the user wants this call to be
eliminated. Then, more interesting things can be implemented
more simply, like a state machine:
void stateA() {
become stateB();
}
void stateB() {
become stateC();
}
void stateC() {
return;
}
void main() {
become stateA();
}
Seems nice.
I'm not sure how D handles stack sizes, so this may be an issue
as well if stack sizes are determined at runtime.
D doesn't currently support C99 VLAs, but it supports alloca(),
so stack frames are sized dynamically. But maybe this is not a
big problem for CPS.
Bye,
bearophile
