add consistent prod_left and prod_right methods

Author: rheard

quatint/quat.py

@@ -927,6 +927,25 @@ def gcd_right(a: "hurwitzint", b: OP_TYPES) -> "hurwitzint":
     return a.gcd_right(b)
 
 
-def prod_left(x: Iterator[object], start: object = 1):
+def prod_right(x: Iterator[OP_TYPES], unit: Union["hurwitzint", None] = None):
     """Simply a helper method to match existing Python prod syntax"""
-    return functools.reduce(operator.mul, x, 1) * start
+    product: hurwitzint = hurwitzint(1, 0, 0, 0)
+    for sub_x in x:
+        product = sub_x * product
+
+    if unit is None:
+        unit = hurwitzint(1, 0, 0, 0)
+
+    return unit * product
+
+
+def prod_left(x: Iterator[OP_TYPES], unit: Union["hurwitzint", None] = None):
+    """Simply a helper method to match existing Python prod syntax"""
+    primes: hurwitzint = hurwitzint(1, 0, 0, 0)
+    for sub_x in x:
+        primes *= sub_x
+
+    if unit is None:
+        unit = hurwitzint(1, 0, 0, 0)
+
+    return primes * unit

tests/test_quat.py

@@ -1,12 +1,12 @@
-from math import isqrt, prod
+from math import isqrt
 from pathlib import Path
 from typing import Union
 
 from hurwitz import HurwitzQuaternion
 
 import quatint.quat
 
-from quatint.quat import hurwitzint, prod_left
+from quatint.quat import hurwitzint, prod_left, prod_right
 
 def test_compiled_tests():
     """Verify that we are running these tests with a compiled version of hurwitzint"""
@@ -344,7 +344,7 @@ def test_main(self):
         """Validate factor works as expected."""
         factors = self.b_int.factor_right()
 
-        ans = prod(reversed(factors.primes), start=factors.unit)
+        ans = prod_right(factors.primes, unit=factors.unit)
 
         self.assert_equal(self.b_int, ans)
 
@@ -356,6 +356,6 @@ def test_main(self):
         """Validate factor works as expected."""
         factors = self.b_int.factor_left()
 
-        ans = prod_left(factors.primes, start=factors.unit)
+        ans = prod_left(factors.primes, unit=factors.unit)
 
         self.assert_equal(self.b_int, ans)