In Elixir, functions are grouped by modules that play the role of namespaces. For example, in the previous exercise we used the function puts(text)
from module IO:
IO.puts("Hello, World!")
Modules are defined with a special contstruct defmodule/do/end:
# use CamelCase for name
defmodule HexletBasics do
# Here goes module contains
end
Elixir allows the creation of multiple modules in the same file, but there is a convention to have only one module per file with the same name as the module but in snake_case.
Modules can be nested. By convention, we create nested modules when they are located in a directory. For example, there's the module HexletBasics.Application
located in lib/hexlet_basics/application.ex directory.
defmodule HexletBasics.Application do
# Function
def hello do
IO.puts("Hello, World!")
end
end
Function calls for nested modules are the same as for flat modules. First, we put the module's full name, then a function call.
HexletBasics.Application.hello()
There is a special module Kernel which functions we can call directly.
is_number(13) # true
Kernel contains basic language primitives for arithmetic operations, spawning processes, data type handling, macros for defining new functionality, and more.
Create module My.Super.Module and put the function hello()
we defined above
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Your exercise will be checked with these tests:
1defmodule Test do
2 use ExUnit.Case
3 import ExUnit.CaptureIO
4
5 test "greets the world" do
6 msg = capture_io(fn -> My.Super.Module.hello() end) |> String.trim()
7 assert msg == "Hello, World!"
8 end
9end
10
Teacher's solution will be available in: