Elixir
Definition
Elixir is a dynamic, functional language that runs on the Erlang virtual machine (BEAM). It favors immutability, pattern matching, and first-class functions, and can call Erlang modules directly (e.g. :math.pi(), :os.system_time()).
Core Ideas
Basic types
Strings are UTF-8 encoded binaries (a series of bytes, 1–4 per code point); check with the kernel function is_binary/1. Kernel functions are the basic building blocks — no module prefix needed. Concatenate strings with <>; convert with per-type to_string(). Integers, floats, and booleans round out the basics.
Atoms
Constants whose name is their value (:foobar). Built-ins include true, false, and nil (absence of a value, like Python’s None). The convention :ok / :error signals success or failure — the backbone of Elixir’s return values and pattern matching.
Control flow
Elixir offers if/else/unless, cond (multi-branch, first truthy wins — always end with a true default), case (pattern matching with a _ catch-all, optional when guards), and with (chained <- matches; the do block runs only if all match, else the else clause). Pattern matching is the idiomatic control-flow tool.
First-class & higher-order functions
Functions are values — stored, passed, and returned. Anonymous functions bind to variables and call with dot syntax: multiply = fn x -> x * 10 end; multiply.(2). Higher-order functions take or return functions (e.g. Enum.map).
Comprehensions and the Enum module
Elixir prefers comprehensions over iterators: for n <- numbers, do: n*3 (works over lists, maps, nested generators). The Enum module provides map, filter, each, take, sort, and the pivotal reduce(collection, accumulator, fn(el, acc) -> ... end) — each result becomes the next iteration’s accumulator.
Relationships
- SOLID — contrast: functional composition vs object-oriented design principles
- Software Engineering Practices — immutability and pure functions as engineering habits
References
- Elixir learning summary — atoms, data types, control flow, functions, Enum