So apparently, there's been a big brouhaha over whether or not Python needs tail call optimization. This came to a head when someone shipped Guido a copy of SICP because he didn't "get it." I'm in the same boat as Guido. I understand the concept of tail call optimization. I just can't think of any reason why Python really needs it.
To make this easier for me to understand, could someone give me a snippet of code that would be greatly simplified using TCO?
Tail call optimization makes it easier to write recursive functions without worrying about a stack overflow:
def fac(n, result=1):
if n > 1:
return fac(n - 1, n * result)
return result
Without tail call optimization, calling this with a big number could overflow the stack.
Personally, i put great value on tail call optimization; but mainly because it makes recursion as efficient as iteration (or makes iteration a subset of recursion). On minimalistic languages you get huge expressive power without sacrificing performance.
On a 'practical' language (like Python), OTOH, you usually have a lot of other constructions for almost every situation imaginable, so it's less critical. Always a good thing to have, to allow for unforeseen situations, of course
If you intensely want to use recursion for things that might alternatively be expressed as loops, then "tail call optimization" is really a must. However, Guido, Python's Benevolent Dictator For Life (BDFL), strongly believes in loops being expressed as loops -- so he's not going to special-case tail calls (sacrificing stack-trace dumps and debugging regularity).