F#: Mutually recursive functions [duplicate]

问题

This question already has answers here:

Closed 9 years ago.

Possible Duplicate:
[F#] How to have two methods calling each other?

Hello all,

I Have a scenario where I have two functions that would benefit from being mutually recursive but I'm not really sure how to do this in F#

My scenario is not as simple as the following code, but I'd like to get something similar to compile:

let rec f x =
  if x>0 then
    g (x-1)
  else
    x

let rec g x =
  if x>0 then
    f (x-1)
  else
    x

回答1:

You can also use let rec ... and form:

let rec f x =
  if x>0 then
    g (x-1)
  else
    x

and g x =
  if x>0 then
    f (x-1)
  else
    x

回答2:

To get mutually recursive functions simply pass one to the other as a parameter

let rec f g x =
  if x>0 then
    g (x-1)
  else
    x

let rec g x =
  if x>0 then
    f g (x-1)
  else
    x

回答3:

Use the let rec ... and ... construct:

let rec f x =
  if x>0 then
    g (x-1)
  else
    x

and g x =
  if x>0 then
    f (x-1)
  else
    x

来源：https://stackoverflow.com/questions/3621043/f-mutually-recursive-functions