/* Examples of C99 compound literals and designated initializers.
 */

#include <stdio.h>

struct point {
    int x, y;
};

static struct point point_at(int x, int y)
{
    return (struct point){.x = x, .y = y};
}

typedef struct point point;

static point delta(point a, point b)
{
    return (point) {.x = a.x - b.x, .y = a.y - b.y};
}

static int distsq(point a, point b)
{
    point d = delta(a, b);
    return d.x*d.x + d.y*d.y;
}

/* Untyped λ calculus */
typedef struct ulc
{
    const char *var;
    struct ulc *rator, *rand, *body;
} ulc;

int main()
{
    /* The S-combinator */
    ulc s = { "x", .body = &(ulc) {
            "y", .body = &(ulc) {
                "z", .body = &(ulc) {
                    .rator = &(ulc) {
                        .rator = &(ulc) { "x" }, .rand = &(ulc) { "z" }},
                    .rand = &(ulc) {
                        .rator = &(ulc) { "y" }, .rand = &(ulc) { "z" }}}}}};
                  
    printf("%d\n", distsq((point){2, -1}, (point){5, 3}));
    return 0;
}