defmodule Example.Calculator do
@moduledoc """
Basic calculator operations
"""
@spec add(number(), number()) :: number()
def add(a, b) when is_number(a) and is_number(b), do: a + b
@spec subtract(number(), number()) :: number()
def subtract(a, b) when is_number(a) and is_number(b), do: a - b
@spec multiply(number(), number()) :: number()
def multiply(a, b) when is_number(a) and is_number(b), do: a * b
@spec divide(number(), number()) :: {:ok, number()} | {:error, String.t()}
def divide(_a, 0), do: {:error, "Division by zero"}
def divide(a, b) when is_number(a) and is_number(b), do: {:ok, a / b}
end
defmodule Example.MathUtils do
@moduledoc """
Mathematical utility functions
"""
@spec factorial(non_neg_integer()) :: pos_integer()
def factorial(0), do: 1
def factorial(n) when n > 0, do: n * factorial(n - 1)
@spec is_prime?(integer()) :: boolean()
def is_prime?(n) when n < 2, do: false
def is_prime?(2), do: true
def is_prime?(n) when rem(n, 2) == 0, do: false
def is_prime?(n) do
limit = :math.sqrt(n) |> trunc()
not Enum.any?(3..limit//2, &(rem(n, &1) == 0))
end
@spec fibonacci(non_neg_integer()) :: non_neg_integer()
def fibonacci(0), do: 0
def fibonacci(1), do: 1
def fibonacci(n) when n > 1, do: fibonacci(n - 1) + fibonacci(n - 2)
end
