Example of how to implement a higher order function in C.

map.c

/*
 * Example of higher order functions in C.
 */
#include <stdio.h>


void func ( void (*f)(int, int) ) {
    int ctr = 0; 
    for (ctr; ctr < 5; ctr++) {
        (*f)(ctr, ctr);
    }
}

void print (int x, int y) {
    printf("%d %d\n", x, x + y);
}


void main() {
    func(print);
}