Feat: adding logrand and exprand

tests/forth/randomness.rs

@@ -105,3 +105,69 @@ fn ftom_880() {
 fn mtof_ftom_roundtrip() {
     expect_float("60 mtof ftom", 60.0);
 }
+
+#[test]
+fn exprand_in_range() {
+    let f = forth_seeded(12345);
+    f.evaluate("1.0 100.0 exprand", &default_ctx()).unwrap();
+    let val = stack_float(&f);
+    assert!(val >= 1.0 && val <= 100.0, "exprand {} not in [1, 100]", val);
+}
+
+#[test]
+fn exprand_deterministic() {
+    let f1 = forth_seeded(99);
+    let f2 = forth_seeded(99);
+    f1.evaluate("1.0 100.0 exprand", &default_ctx()).unwrap();
+    f2.evaluate("1.0 100.0 exprand", &default_ctx()).unwrap();
+    assert_eq!(f1.stack(), f2.stack());
+}
+
+#[test]
+fn exprand_swapped_args() {
+    let f1 = forth_seeded(42);
+    let f2 = forth_seeded(42);
+    f1.evaluate("1.0 100.0 exprand", &default_ctx()).unwrap();
+    f2.evaluate("100.0 1.0 exprand", &default_ctx()).unwrap();
+    assert_eq!(f1.stack(), f2.stack());
+}
+
+#[test]
+fn exprand_requires_positive() {
+    expect_error("0.0 10.0 exprand", "exprand requires positive values");
+    expect_error("-1.0 10.0 exprand", "exprand requires positive values");
+    expect_error("1.0 0.0 exprand", "exprand requires positive values");
+}
+
+#[test]
+fn logrand_in_range() {
+    let f = forth_seeded(12345);
+    f.evaluate("1.0 100.0 logrand", &default_ctx()).unwrap();
+    let val = stack_float(&f);
+    assert!(val >= 1.0 && val <= 100.0, "logrand {} not in [1, 100]", val);
+}
+
+#[test]
+fn logrand_deterministic() {
+    let f1 = forth_seeded(99);
+    let f2 = forth_seeded(99);
+    f1.evaluate("1.0 100.0 logrand", &default_ctx()).unwrap();
+    f2.evaluate("1.0 100.0 logrand", &default_ctx()).unwrap();
+    assert_eq!(f1.stack(), f2.stack());
+}
+
+#[test]
+fn logrand_swapped_args() {
+    let f1 = forth_seeded(42);
+    let f2 = forth_seeded(42);
+    f1.evaluate("1.0 100.0 logrand", &default_ctx()).unwrap();
+    f2.evaluate("100.0 1.0 logrand", &default_ctx()).unwrap();
+    assert_eq!(f1.stack(), f2.stack());
+}
+
+#[test]
+fn logrand_requires_positive() {
+    expect_error("0.0 10.0 logrand", "logrand requires positive values");
+    expect_error("-1.0 10.0 logrand", "logrand requires positive values");
+    expect_error("1.0 0.0 logrand", "logrand requires positive values");
+}