🚀 go-pugleaf

>the question was:  how do I write a function
	typedef int i2ifn(int);
	i2ifn compose(i2ifn f, i2ifn g) { /* fill this in */ }
>so that compose(f,g)(x) == f(g(x)).


you say

int (*f1)(), (*f2)();

int retval (x) { (*f1)((*f2)(x));}

int (*compose (f, g))()
   int (*f)(), (*g)();
   {
      f1 = f;
      f2 = g;
      return (retval);
   }



if you don't like using global variables, then you have to
say

struct CLOSURE {
   int (*func)();
   struct LOCALS *locals;
}
with the understanding that applying a closure is to say
(*func)(locals, args...),
and that any (would-be)local variables that the called function 
uses are found in the struct LOCALS.

this is plain, portable C.

bb