big commit

tests/forth/arithmetic.rs

@@ -150,3 +150,53 @@ fn chain() {
 fn underflow() {
     expect_error("1 +", "stack underflow");
 }
+
+#[test]
+fn pow_int() {
+    expect_int("2 3 pow", 8);
+}
+
+#[test]
+fn pow_float() {
+    expect_float("2 0.5 pow", std::f64::consts::SQRT_2);
+}
+
+#[test]
+fn sqrt() {
+    expect_int("16 sqrt", 4);
+}
+
+#[test]
+fn sqrt_float() {
+    expect_float("2 sqrt", std::f64::consts::SQRT_2);
+}
+
+#[test]
+fn sin_zero() {
+    expect_int("0 sin", 0);
+}
+
+#[test]
+fn sin_pi_half() {
+    expect_float("3.14159265358979 2 / sin", 1.0);
+}
+
+#[test]
+fn cos_zero() {
+    expect_int("0 cos", 1);
+}
+
+#[test]
+fn cos_pi() {
+    expect_int("3.14159265358979 cos", -1);
+}
+
+#[test]
+fn log_e() {
+    expect_float("2.718281828459045 log", 1.0);
+}
+
+#[test]
+fn log_one() {
+    expect_int("1 log", 0);
+}