Elixir - The Love Child of Ruby and Erlang

The article presents Elixir as a functional, meta-programmable language built on the Erlang VM and notes its Ruby influence through José Valim. It then walks through the language’s main features with short IEx examples.

Reading notes

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• IEx is the interactive shell, and it includes syntax highlighting and built-in documentation access with commands like h(Enum) and h(Enum.reverse).
• Elixir supports higher-order functions, so functions can be passed as arguments and returned as values, as shown with Enum.map and an anonymous square function.
• List comprehensions are available, but the article says List and Enum functions are often more flexible.
• Pattern matching is inherited from Prolog through Erlang and is used to destructure lists, tuples, atoms, and strings.
• Elixir data structures are immutable, so calling List.delete returns a new list without changing the original variable.
• Recursion replaces loops in the example MyList.length, which uses arity and pattern matching on empty and non-empty lists.
• Streams are lazy, which makes them suitable for infinite data sources and remote feeds, and the example uses Stream.repeatedly with Enum.take.
• The pipe operator |> passes the left-side result as the first argument to the next function, improving readability in chained calls.
• Elixir processes communicate by message passing, and the Greeter example uses receive with pattern matching to handle different message types.
• spawn starts a process and returns a pid, while unrecognized messages fall through to the catch-all _ pattern.
• Elixir can call Erlang functions and libraries directly because both share the same byte code, and it also has access to Erlang’s OTP framework.
• The article closes by pointing readers to official documentation, books on Elixir and Erlang, and learning resources for Erlang.