dev(dtypes): add a function to make Integers able to hold a set of values

hdk/common/data_types/integers.py

@@ -1,5 +1,8 @@
 """This file holds the definitions for integer types"""
 
+import math
+from typing import Iterable
+
 from . import base
 
 
@@ -79,3 +82,60 @@ def create_unsigned_integer(bit_width: int) -> Integer:
 
 
 UnsignedInteger = create_unsigned_integer
+
+
+def make_integer_to_hold_ints(values: Iterable[int], force_signed: bool) -> Integer:
+    """Returns an Integer able to hold all values, it is possible to force the Integer to be signed
+
+    Args:
+        values (Iterable[int]): The values to hold
+        force_signed (bool): Set to True to force the result to be a signed Integer
+
+    Returns:
+        Integer: The Integer able to hold values
+    """
+    assert all(map(lambda x: isinstance(x, int), values))
+    min_value = min(values)
+    max_value = max(values)
+
+    make_signed_integer = force_signed or min_value < 0
+
+    num_bits = max(
+        get_bits_to_represent_int(min_value, make_signed_integer),
+        get_bits_to_represent_int(max_value, make_signed_integer),
+    )
+
+    return Integer(num_bits, is_signed=make_signed_integer)
+
+
+def get_bits_to_represent_int(value: int, force_signed: bool) -> int:
+    """Returns how many bits are required to represent a single int
+
+    Args:
+        value (int): The int for which we want to know how many bits are required
+        force_signed (bool): Set to True to force the result to be a signed Integer
+
+    Returns:
+        int: required amount of bits
+    """
+
+    # Writing this in a very dumb way
+    num_bits: int
+    if value < 0:
+        abs_value = abs(value)
+        if abs_value > 1:
+            num_bits = math.ceil(math.log2(abs_value)) + 1
+        else:
+            # -1 case
+            num_bits = 2
+    else:
+        if value > 1:
+            num_bits = math.ceil(math.log2(value + 1))
+        else:
+            # 0 and 1 case
+            num_bits = 1
+
+        if force_signed:
+            num_bits += 1
+
+    return num_bits

tests/common/data_types/test_integers.py

@@ -4,7 +4,12 @@ import random
 
 import pytest
 
-from hdk.common.data_types.integers import Integer, SignedInteger, UnsignedInteger
+from hdk.common.data_types.integers import (
+    Integer,
+    SignedInteger,
+    UnsignedInteger,
+    make_integer_to_hold_ints,
+)
 
 
 @pytest.mark.parametrize(
@@ -68,3 +73,40 @@ def test_basic_integers(integer: Integer, expected_min: int, expected_max: int):
 def test_integers_repr(integer: Integer, expected_repr_str: str):
     """Test integer repr"""
     assert integer.__repr__() == expected_repr_str
+
+
+@pytest.mark.parametrize(
+    "values,force_signed,expected_result",
+    [
+        ([0], False, Integer(1, is_signed=False)),
+        ([0], True, Integer(2, is_signed=True)),
+        ([1], False, Integer(1, is_signed=False)),
+        ([1], True, Integer(2, is_signed=True)),
+        ([-1], False, Integer(2, is_signed=True)),
+        ([-2], False, Integer(2, is_signed=True)),
+        ([0, 1], False, Integer(1, is_signed=False)),
+        ([0, 1], True, Integer(2, is_signed=True)),
+        ([7], False, Integer(3, is_signed=False)),
+        ([7], True, Integer(4, is_signed=True)),
+        ([8], False, Integer(4, is_signed=False)),
+        ([8], True, Integer(5, is_signed=True)),
+        ([-7], False, Integer(4, is_signed=True)),
+        ([-8], False, Integer(4, is_signed=True)),
+        ([-7, -8], False, Integer(4, is_signed=True)),
+        ([-9], False, Integer(5, is_signed=True)),
+        ([-9], True, Integer(5, is_signed=True)),
+        ([0, 127], False, Integer(7, is_signed=False)),
+        ([0, 127], True, Integer(8, is_signed=True)),
+        ([0, 128], False, Integer(8, is_signed=False)),
+        ([0, 128], True, Integer(9, is_signed=True)),
+        ([-1, 127], False, Integer(8, is_signed=True)),
+        ([-256, 127], False, Integer(9, is_signed=True)),
+        ([-128, 127], False, Integer(8, is_signed=True)),
+        ([-128, 128], False, Integer(9, is_signed=True)),
+        ([-13, 4], False, Integer(5, is_signed=True)),
+        ([42, 1019], False, Integer(10, is_signed=False)),
+    ],
+)
+def test_make_integer_to_hold(values, force_signed, expected_result):
+    """Test make_integer_to_hold"""
+    assert expected_result == make_integer_to_hold_ints(values, force_signed)