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.
In elixir, you can do it like following as well
With
cond
With
case
But I still like the function head pattern matching with guards(can be weird at first, at least for me but then it makes sense).
This allows the compiler to optimize the function call. 💪
If you don't like it there are other options like above ⬆️
After all both Ruby and Elixir looks fine to me. ✌️