Any SML coders able to translate this to Python?

Marko Rauhamaa marko at pacujo.net
Thu Sep 6 00:29:32 EDT 2018


Marko Rauhamaa <marko at pacujo.net> (Marko Rauhamaa):
> Steven D'Aprano <steve+comp.lang.python at pearwood.info>:
>> I have this snippet of SML code which I'm trying to translate to Python:
>>
>> fun isqrt n = if n=0 then 0
>>              else let val r = isqrt (n/4)
>>                   in
>>                     if n < (2*r+1)^2 then 2*r
>>                     else 2*r+1
>>                   end
> [...]
> You must make sure "r" doesn't leak outside its syntactic context so:
>
> def isqrt(n):
>     if n == 0:
>         return 0
>     else:
>         def f2398478957():
>             r = isqrt(n//4)
>             if n < (2*r+1)**2:
>                 return 2*r
>             else:
>                 return 2*r+1
>         return f2398478957()

Actually, this is a more direct translation:

   def isqrt(n):
       if n == 0:
           return 0
       else:
           def f2398478957(r):
               if n < (2*r+1)**2:
                   return 2*r
               else:
                   return 2*r+1
           return f2398478957(isqrt(n//4))


Marko



More information about the Python-list mailing list