Comment by phplovesong
11 hours ago
TCO can be implemented easily in non TC optimized langauges with a trampoline wrapper.
Why do i need a fully fledged library for something that is basically a few lines of code?
11 hours ago
TCO can be implemented easily in non TC optimized langauges with a trampoline wrapper.
Why do i need a fully fledged library for something that is basically a few lines of code?
There's quite a bit of overhead.
I believe Clojure does it with trampoline as JVM does not (as far as I know) does not support tail call optimization. Ironic, given Guy Steele.
Yes, Clojure doesn't have TCO either.
You get `(loop ... (recur ...))` or `trampoline`.
Naive recursion will consume the stack.
https://clojuredocs.org/clojure.core/loop
https://clojuredocs.org/clojure.core/recur
https://clojuredocs.org/clojure.core/trampoline
Nor can you count on Common Lisp to have TCO. People who are new to CL and treat it like Scheme run into this constantly. Basically never recur down a list, since the list could be long.
This problem also shows up in cases where TCO is not possible. For example, suppose we have a syntax tree for some program and need to traverse the tree. Nodes that represent lists of things might have a long list of children, and in a sufficiently large program recursing down that list can blow out the stack. Just recurse on list elements, which one can reasonably assume don't nest too deeply.