add sum function for addition of two registers

bitutilities.py

@@ -27,6 +27,10 @@ class BasicRegister:
         shifted_radices: deque[bool] = deque([self.memory.pop() for _i in range(steps_shifted)])
         return shifted_radices
 
+    def adjust_size(self, s: int) -> None:
+        current_memory_size: int = len(self.memory)
+        return BasicRegister([False] * max(s - current_memory_size, 0) + list(self.memory)[-current_memory_size:])
+
 
 def get_memory(variable_name: str) -> list[bool]:
     """
@@ -44,3 +48,39 @@ def get_memory(variable_name: str) -> list[bool]:
             return [True if character == "1" else False for character in input_chars]
         else:
             print(f"[ERROR] The {variable_name} may contain only 1-s and 0-s!")
+
+
+def sum(a_original: BasicRegister, b_original: BasicRegister) -> BasicRegister:
+    """
+    Sums two registers' values.
+
+    :param BasicRegister a: First register.
+    :param BasicRegister b: Second register.
+
+    :return: Register containing the result.
+    :rtype: BasicRegister
+    """
+    size_a = len(a_original.memory)
+    size_b = len(b_original.memory)
+
+    required_size = max(size_a, size_b)
+
+    if size_a != size_b:
+        a = a_original.adjust_size(required_size)
+        b = b_original.adjust_size(required_size)
+    else:
+        a = a_original
+        b = b_original
+
+    c = BasicRegister([False] * required_size)
+
+    carry = False
+    for i in range(size_a - 1, 0, -1):
+        current_bit_sum = a.memory[i] + b.memory[i] + carry
+        carry = bool(current_bit_sum & 2)
+        c.memory[i] = bool(current_bit_sum & 1)
+
+    final_bit_sum = a.memory[0] + b.memory[0] + carry
+    c.memory[0] = bool(final_bit_sum & 1)
+
+    return c

main.py

@@ -20,3 +20,9 @@ if __name__ == '__main__':
     print("\nShifted right:")
     print([int(value) for value in reg.right_shift()])
     print(reg)
+
+    reg2: BasicRegister = BasicRegister(get_memory("more memory"))
+
+    reg3: BasicRegister = sum(reg, reg2)
+
+    print(reg3)