#version 100

composite main(in a1, in a2, in a3, out b1, out b2) {
	new reonode({a1, a2, a3}, {b1, b2});
}

composite reonode(in[] a, out[] b) {
	channel co -> ci;
	new merger(a, co);
	new replicator(ci, b);
}

composite replicator(in a, out[] b) {
	if (b.length == 0) {
		new blocking(a);
	} else if (b.length == 1) {
		new sync(a, b[0]);
	} else {
		channel xo -> xi;
		new binary_replicator(a, b[0], xo);
		new replicator(xi, b[1 : b.length - 1]);
	}
}
primitive binary_replicator(in a, out b, out c) {
    while (true) {
        synchronous {
            if (fires(a) && fires(b) && fires(c)) {
                msg x = get(a);
                put(b, x);
                put(c, x);
            } else {
                assert !fires(a) && !fires(b) && !fires(c);
            }
        }
    }
}
primitive blocking(in a) {
	while (true) synchronous {
		assert !fires(a);
	}
}

composite merger(in[] a, out b) {
	if (a.length == 0) {
		new silent(b);
	} else {
		in prev = a[0];
		int i = 1;
		while (i < a.length) {
			channel yi -> yo;
			new binary_merger(prev, a[i], yo);
			prev = yi;
			i++;
		}
		new sync(prev, b);
	}
}
primitive binary_merger(in a, in b, out c) {
    while (true) {
        synchronous {
            if (fires(a) && fires(c)) {
                assert !fires(b);
                put(c, get(a));
            } else if (fires(b) && fires(c)) {
                assert !fires(a);
                put(c, get(b));
            } else {
                assert !fires(a) && !fires(b) && !fires(c);
            }
        }
    }
}
primitive silent(out a) {
	while (true) synchronous {
		assert !fires(a);
	}
}

primitive sync(in a, out b) {
    while (true) {
        synchronous {
            if (fires(a) && fires(b)) {
            	put(b, get(a));
            } else {
                assert !fires(a) && !fires(b);
            }
        }
    }
}