新しい言語を学ぶ!

# How do I define basic types? (Integers, Floats, Booleans, Strings, Array)
an_int = 1
an_float = 1.0
an_bool = true
an_str = "Elixir"
an_arr = [1, 2, 3]

# How do I concatenate or interpolate strings?
ans = "Forty-two"
meaning = "The answer to the great question.. Of Life, the Universe and Everything.. Is.. #{ans}."

# How do I read from/write to the console?
user_name = IO.gets("What's your name? ") # Trailing space to look nicer in console
IO.puts("Hello, #{user_name}!")
# Note that you get the trailing newline with gets- so you'll likely want to trim
x = String.trim(IO.gets("?"))
x = IO.gets("?") |> String.trim() # Can also pipe - easier on the eyes?

# What are the basic control flow statements? (`if/else`, `foreach`, `switch` etc.) 
# https://elixir-lang.org/getting-started/case-cond-and-if.html
# https://elixir-lang.org/getting-started/recursion.html
if true do
    # ...
else
    # ...
end

unless true do
    # ...
end

for(i = 0; i < sizeof(array); i++) {
  array[i] = array[i] * 2;
}
# Enum module also has map and reduce functions
# https://elixir-lang.org/getting-started/enumerables-and-streams.html#enumerables
Enum.map([1, 2, 3], fn x -> x * 2 end)
# [2, 4, 6]
IO.puts(Enum.reduce([1, 2, 3], 0, fn x, acc -> acc + x * 2 end))
# 12

beats = case play do
    "scissors" -> "paper"
    "paper" -> "rock"
    "rock" -> "lizard"
    "lizard" -> "spock"
    "spock" -> "scissors"
    "scissors" -> "lizard"
    "lizard" -> "paper"
    "paper" -> "spock"
    "spock" -> "rock"
    "rock" -> "scissors"
end

# How do I define functions and methods?
# (Elixir is functional, and doesn't have concept of Objects, Classes and Methods)
defmodule MyModule
    def sum(a, b)
        a + b
    end
end

# How do I control the visibility of those functions and methods?
defp im_a_private_function
    # ...
end

# Can I define anonymous functions?
sum = fn (a, b) -> a + b end
sum = &(&1 + &2) # Shorthand using &
# Note, these need to be called with .
x = sum.(2, 3) # -> 5

# How do exceptions work? How do I handle them?
# https://elixir-lang.org/getting-started/try-catch-and-rescue.html

raise ArgumentError, message: "Argument out of range"

try do
    # ...Code that might raise
rescue
    ArgumentException -> "Caught the ArgumentException"
end

# Define custom exceptions via a Module with defexception
defmodule MyError
    defexception message: "Default message"
end