Init

tests/forth/randomness.rs

@@ -0,0 +1,118 @@
+use super::harness::*;
+
+#[test]
+fn rand_in_range() {
+    let f = forth_seeded(12345);
+    f.evaluate("0 10 rand", &default_ctx()).unwrap();
+    let val = stack_float(&f);
+    assert!(val >= 0.0 && val < 10.0, "rand {} not in [0, 10)", val);
+}
+
+#[test]
+fn rand_deterministic() {
+    let f1 = forth_seeded(99);
+    let f2 = forth_seeded(99);
+    f1.evaluate("0 100 rand", &default_ctx()).unwrap();
+    f2.evaluate("0 100 rand", &default_ctx()).unwrap();
+    assert_eq!(f1.stack(), f2.stack());
+}
+
+#[test]
+fn rrand_inclusive() {
+    let f = forth_seeded(42);
+    for _ in 0..20 {
+        f.clear_stack();
+        f.evaluate("1 3 rrand", &default_ctx()).unwrap();
+        let val = stack_int(&f);
+        assert!(val >= 1 && val <= 3, "rrand {} not in [1, 3]", val);
+    }
+}
+
+#[test]
+fn seed_resets() {
+    let f1 = forth_seeded(1);
+    f1.evaluate("42 seed 0 100 rand", &default_ctx()).unwrap();
+    let f2 = forth_seeded(999);
+    f2.evaluate("42 seed 0 100 rand", &default_ctx()).unwrap();
+    assert_eq!(f1.stack(), f2.stack());
+}
+
+#[test]
+fn coin_binary() {
+    let f = forth_seeded(42);
+    f.evaluate("coin", &default_ctx()).unwrap();
+    let val = stack_int(&f);
+    assert!(val == 0 || val == 1);
+}
+
+#[test]
+fn chance_zero() {
+    // 0.0 probability should never execute the quotation
+    let f = run("99 { 42 } 0.0 chance");
+    assert_eq!(stack_int(&f), 99); // quotation not executed, 99 still on stack
+}
+
+#[test]
+fn chance_one() {
+    // 1.0 probability should always execute the quotation
+    let f = run("{ 42 } 1.0 chance");
+    assert_eq!(stack_int(&f), 42);
+}
+
+#[test]
+fn choose_from_list() {
+    let f = forth_seeded(42);
+    f.evaluate("10 20 30 3 choose", &default_ctx()).unwrap();
+    let val = stack_int(&f);
+    assert!(val == 10 || val == 20 || val == 30);
+}
+
+#[test]
+fn choose_underflow() {
+    expect_error("1 2 5 choose", "stack underflow");
+}
+
+#[test]
+fn cycle_deterministic() {
+    for runs in 0..6 {
+        let ctx = ctx_with(|c| c.runs = runs);
+        let f = run_ctx("10 20 30 3 cycle", &ctx);
+        let expected = [10, 20, 30][runs % 3];
+        assert_eq!(stack_int(&f), expected, "cycle at runs={}", runs);
+    }
+}
+
+#[test]
+fn cycle_zero_count() {
+    expect_error("1 2 3 0 cycle", "cycle count must be > 0");
+}
+
+#[test]
+fn mtof_a4() {
+    expect_float("69 mtof", 440.0);
+}
+
+#[test]
+fn mtof_octave() {
+    expect_float("81 mtof", 880.0);
+}
+
+#[test]
+fn mtof_c4() {
+    expect_floats_close("60 mtof", 261.6255653, 0.001);
+}
+
+#[test]
+fn ftom_440() {
+    expect_float("440 ftom", 69.0);
+}
+
+#[test]
+fn ftom_880() {
+    expect_float("880 ftom", 81.0);
+}
+
+#[test]
+fn mtof_ftom_roundtrip() {
+    expect_float("60 mtof ftom", 60.0);
+}