Re:Lisp in Dart 2.0
by codebje on Sunday September 23, 2018 @06:45PM
(#18053732)
There's no difference.
When you exit a function, you must clean up local stack allocations. It doesn't matter if you exit with a return or a jump. It doesn't matter where you jump. If you leave the stack with temporary allocations in place, they'll leak space.
(A compiler pipeline may, at some point, observe that releasing stack space, jumping, then claiming the same amount of stack space could be optimised to just a jump, but it may equally observe that releasing, jumping, and claiming a different amount could be optimised to either releasing or claiming the difference, then jumping, too - there's still no difference between recursive, co-recursive, and non-recursive tail calls.)
When you exit a function, you must clean up local stack allocations. It doesn't matter if you exit with a return or a jump. It doesn't matter where you jump. If you leave the stack with temporary allocations in place, they'll leak space.
(A compiler pipeline may, at some point, observe that releasing stack space, jumping, then claiming the same amount of stack space could be optimised to just a jump, but it may equally observe that releasing, jumping, and claiming a different amount could be optimised to either releasing or claiming the difference, then jumping, too - there's still no difference between recursive, co-recursive, and non-recursive tail calls.)