[nem-en] Re: Mutually recursive local functions.

[Radu Grigore]

On 7/3/07, Elifant <elifantu at mail.ru> wrote:
> Michal Moskal пишет:
> I've added it at
> http://nemerle.org/Grok_Base_structure_of_programs#Local_functions,
> but I can't think out simple and useful example of use. So I just wrote
> dumb code.

One (common?) use is to log the parameters and the return value of a
recursive function.

def fib(n)
  if (n<2) n
  else fib(n-1)+fib(n-2)

gets changed into

def fibNoLog(n)
  if (n<2) n
  else fib(n-1)+fib(n-2)
and fib(n)
  def r = fibNoLog(n)
  WriteLine($"fib($n)=$r")

The transformation is automatic and easy to do. Modifying a
complicated recursive function might not be as convenient especially
if it has multiple return points.

-- 
regards,
 radu
http://rgrig.blogspot.com/