repos / gbc

switch.b

 1assert_equal(actual, expected, message) {
 2    extrn printf, abort;
 3    printf("%s: ", message);
 4    if (actual != expected) {
 5        printf("FAIL\n");
 6        abort();
 7    } else {
 8        printf("OK\n");
 9    }
10}
11
12test_lookup(a, b) {
13  switch a {
14    case 69:
15      return (690);
16
17    case 420:
18      switch b {
19        case 420:
20          return (42);
21        case 1337:
22          return (7331);
23      }
24      // default:
25      return (-2);
26
27  }
28  // default:
29  return (-1);
30}
31
32/* TODO: maybe this should be a part of the libb at some point?
33 * iirc snake example also uses a similar function
34 */
35unreachable(message) {
36  extrn printf, abort;
37  printf("UNREACHABLE: %s\n", message);
38  abort();
39}
40
41test_fallthrough(x) {
42    extrn printf;
43    switch (x) {
44    unreachable("test_fallthrough");
45    case 0: printf("0\n");
46    case 1: printf("1\n");
47    case 2: printf("2\n");
48    case 3: printf("3\n");
49    case 4: printf("4\n");
50    }
51}
52
53main() {
54  extrn printf, assert_equal;
55
56  assert_equal(test_lookup(69,69),    690,  "(69,69)    => 690");
57  assert_equal(test_lookup(420,420),  42,   "(420,420)  => 42");
58  assert_equal(test_lookup(420,1337), 7331, "(420,1337) => 7331");
59  assert_equal(test_lookup(420,69),   -2,   "(420,69)   => -2");
60  assert_equal(test_lookup(34,35),    -1,   "(34,35)    => -1");
61
62  printf("------------------------------\n");
63  test_fallthrough(0);
64  printf("------------------------------\n");
65  test_fallthrough(3);
66
67  /* According to kbman the syntax of switch-case is `switch rvalue statement`.
68   * So bellow are valid cases.
69   */
70  switch 69 {
71    unreachable("curly");
72  }
73  switch 69 unreachable("inline");
74}