On Tue, 29 Nov 2011 13:57:32 +1100, Chris Angelico wrote: > I'm inclined toward an alternative: explicit recursion. Either a > different syntax, or a special-case on the use of the function's own > name, but whichever syntax you use, it compiles in a "recurse" opcode. > That way, if name bindings change, it's still going to recurse - > something few languages guarantee, and therefore few languages can > optimize.
As I recall, Forth uses (or used) a special RECURSE word which turned on the recursion bit while compiling, so that the compiled word could see itself. By memory, the (incomplete) definition: : fact dup 1- fact * ; would fail, unless you happened to already have another word called fact existing at compilation time. To make it recurse correctly, the compiler needs to make sure that the namespace fact sees includes itself: RECURSE : fact dup 1- fact * ; which should work, apart from the embarrassing fact that I don't recall the syntax for conditional jumps and so the recursion never terminates. :) -- Steven -- http://mail.python.org/mailman/listinfo/python-list
