Alquimia 2.3

Pattern Matching

my_int = 10

my_int = 15

# pin operator
^my_int = 10

[] = ["element"]

%{} = %{"alquimia" => "learning"}

%{"alquimia" => "e-learning"} = %{"alquimia" => "learning"}

[alquimia: "learning", elixir: "basic"] = [elixir: "basic", alquimia: "learning"]

{:ok, _} = {:ok, %{}}
{:ok, %{"a" => [_ | t]}} = {:ok, %{"a" => [1, 2, 3, 4]}}

Functions and Modules

defmodule Math do
  @moduledoc """
  Documentation explaining the logic contained in this module.
  """

  @doc """
  Sums two numbers.
  """
  @spec sum(a :: Integer.t(), b :: Integer.t()) :: Integer.t()
  def sum(a, b), do: a + b

  @doc """
  Subtracts seconf number from the first.
  """
  @spec sub(Integer.t(), Integer.t()) :: Integer.t()
  def sub(a, b), do: do_sub(a, b)

  @doc false
  def do_sub(a, b) when is_integer(a) and is_integer(b), do: a - b

  # Math.mult/2
  def mult(a, b \\ 1), do: a * b

  def int_div(a, b), do: div(a, b)
end

Math.sum(0, 50)

Math.do_sub(5, 5)

Math.mult(400, 5)

Math.mult(400)

Math.int_div(10, 2)

output_func = fn string -> IO.puts("#{string}") end

output_func.("my_string")

output_func = &IO.puts(&1)

output_func.("my other string")

Pipe Operator

Integer.to_string(String.to_integer("15"))

"15"
|> String.to_integer()
|> Integer.to_string()

require Integer

10
|> Integer.is_odd()
|> if(do: "Integer is odd", else: "Integer is even")

Recursion and tail-call optimization

defmodule MyRecursionModule do
  def non_optimized_factorial(0), do: 1
  def non_optimized_factorial(n), do: n * non_optimized_factorial(n - 1)

  def optimized_factorial(n, acc \\ 1)
  def optimized_factorial(0, acc), do: 1 * acc
  def optimized_factorial(n, acc), do: optimized_factorial(n - 1, acc * n)
end