Example usage of closure header in C

main.c

/**
 * A tiny language experiment, defining closures in C.
 * The reference python-code that is implemented:
 *
 * def add(a):
 *     return (lambda b: a + b)
 *
 * def main():
 *     c = add(5)
 *     print('c(10) =', c(10))
 */


#include <stdio.h>
#include "closure.h"

/* Type definitions */
DEFINE_CLOSURE_TYPE(int, add, int); // closure from int arg to int return value

/* Function definitions */
DEFINE_CLOSURE_ENVIRONMENT_1(add, int); // closure captures one int argument
DEFINE_CLOSURE_BLOCK(int, add, int b) // defines returned functions behaviour 
{
    ENV_ARG_0(int, a); // access captured arg from environment
    return a + b;
}

int main()
{
    CLOSURE(add) c = add(5); // call capture function and store returned closure
    printf("c(10) = %d\n", CALL_LOCAL_CLOSURE(c, 10)); // call closure
    FREE_LOCAL_CLOSURE(c); // manually free
    return 0;
}