On 2007-02-15, Gabriel Genellina <[EMAIL PROTECTED]> wrote: > En Thu, 15 Feb 2007 13:37:19 -0300, Neil Cerutti <[EMAIL PROTECTED]> > escribió: > >> On 2007-02-15, Gabriel Genellina <[EMAIL PROTECTED]> wrote: >>> En Wed, 14 Feb 2007 10:41:53 -0300, Neil Cerutti <[EMAIL PROTECTED]> >>> escribió: >>>> So the effect is that mutual recursion isn't actually any >>>> harder. >>> >>> But some kind of language support is required in this case. At >>> least I don't know how to handle mutual recursion (apart from >>> inlining one function inside the other...). But I'm certainly >>> not a "program transformation guru" (neither a novice!) so I >>> would not be surprised if someone says it can be done... >> >> What happens (using the model of an imaginary virtual machine, >> perhaps like the Python interpreter) is the following. >> >> A normal function call pushes a call-frame onto a stack. The >> call-frame contains information necessary for returning from the >> function, and usually a place to store its local variables and >> parameters. >> >> A function called in "tail" position simply overwrites the >> current call-frame with the new one instead of pushing it onto >> the stack. > > This is the "kind of language support" menctioned. For tail > recursion you don't require that support.
I'm not sure what you mean. The above support is enough for tail recursion, mutual recursion, and any other tail call to be "optimized." -- Neil Cerutti -- http://mail.python.org/mailman/listinfo/python-list
