Implement math.hypot and math.copysign

integration_tests/test_math_02.py

@@ -1,6 +1,6 @@
 from math import (sin, cos, tan, pi, sqrt, log, log10, log2, erf, erfc, gamma,
                   lgamma, asin, acos, atan, atan2, asinh, acosh, atanh,
-                  tanh, sinh, cosh)
+                  tanh, sinh, cosh, hypot, copysign)
 
 def test_trig():
     # TODO: importing from `math` doesn't work here yet:
@@ -46,7 +46,20 @@ def test_hyperbolic():
     assert abs(cosh(1.0) - 0) < eps
     assert abs(tanh(0.0) - 0) < eps
 
+def test_copysign():
+    eps: f64 = 1e-12
+    assert abs(copysign(-8.56, 97.21) - 8.56) < eps
+    assert abs(copysign(-43.0, -76.67) - (-43.0)) < eps
+
+def test_hypot():
+    eps: f64 = 1e-12
+    assert abs(hypot(3, 4) - 5.0) < eps
+    assert abs(hypot(-3, 4) - 5.0) < eps
+    assert abs(hypot(6, 6) - 8.48528137423857) < eps
+
 test_trig()
 test_sqrt()
 test_log()
 test_special()
+test_copysign()
+test_hypot()

src/runtime/math.py

@@ -140,6 +140,24 @@ def lcm(a: i32, b: i32) -> i32:
         return 0
     return (a*b)//gcd(a, b)
 
+
+def copysign(x: f64, y: f64) -> f64:
+    """
+    Return `x` with the sign of `y`.
+    """
+    if y > 0.0 or (y == 0.0 and atan2(y, -1.0) > 0.0):
+        return fabs(x)
+    else:
+        return -fabs(x)
+
+
+def hypot(x: i32, y: i32) -> f64:
+    """
+    Returns the hypotenuse of the right triangle with sides `x` and `y`.
+    """
+    return sqrt(1.0*(x**2 + y**2))
+
+
 def sqrt(x: f64) -> f64:
     return x**(1/2)