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sml

Hiding mutual recursive functions in SML

I have two functions that rely on each other heavily. Each one must use the other one in order to perform the desired task.

I used the and operator in SML when I used them.

The problem is that I am required to hide every single function that is not the main one. I was taught to use local in order to perform this but I never reached this situation, I can't understand how something like this will work syntax wise.

I am referring to something like this:

local
  f()
in
 g()
end;

Is there any way to do this?

Solution

  • You need a third "main" function to start things off – your local f can't be mutually recursive with g.

    Like this:

    local
    fun f x = something with g
    and g x = something with f
in 
    fun h x = whatever
end