This is a example on pattern matching.
Given the Map/Hash input:
input = %{name: "Alice Foo", points: 100, email: "alicefoo@myemail.com"}
The goal is to determine the user rank, by its points:
0..50
-> Starter50..200
-> Member>200
-> Veteran
The code in Elixir using pattern matching:
defmodule Rank do
@moduledoc """
Offers means to perform user ranking computations.
"""
@typedoc """
A user rank.
"""
@type rank :: :starter | :member | :veteran
@doc """
Finds the rank of a given user.
"""
@spec find(%{points: integer()}) :: rank()
def find(%{points: n}) when n <= 50, do: :starter
def find(%{points: n}) when n <= 200, do: :member
def find(_user), do: :veteran
end
Here's how you use it:
iex(1)> Rank.find(input)
:member
The same code in Ruby:
class Rank
# Offer means to perform ranking computations.
# Finds the rank of a given user.
def self.find(user)
case user[:points]
when 0..50
:starter
when 50..200
:member
else
:veteran
end
end
end
And running it:
irb(main):001:0> Rank.find(input)
=> :member
Patter matching makes the code more elegant, expressive and easier to read.
This honestly reads more like English to me than the elixir example.
Case statements are generally looked down upon to solve problems like these in any language...