Elixir Lab Examples

Thirty-six runnable single-file Elixir scripts that follow the track's lesson order, grouped by phase. Every file is self-contained and fully commented. Run them with elixir demo/<group>/NN_name.exs, or open them in the code viewer and change one thing, then run again — that second run is where the learning happens.

Foundations

Hello world, expressions, pipes, and scripts that read their environment — the four files every later demo assumes you have seen.

#	Description	Link
1	Hello world — modules, interpolation, @doc and @moduledoc	View
2	Expressions and pipes — everything returns a value	View
3	Conditionals — if/unless, cond, and the case workhorse	View
4	Scripts that read the world — argv, env vars, and file IO	View

Language Core

Immutability, matching, recursion, collections, polymorphism, errors, and binaries — the vocabulary of idiomatic Elixir.

#	Description	Link
5	Immutability — rebinding, update syntax, structural sharing	View
6	Pattern matching — destructuring, pin, function heads	View
7	Guards and with — refining matches, happy-path pipelines	View
8	Functions and captures — defaults, closures, the & shorthand	View
9	Recursion and tail calls — body vs accumulator style	View
10	Enum and Stream — eager vs lazy pipelines on the same data	View
11	Comprehensions — for with generators, filters, and into:	View
12	Maps and structs — Access, update syntax, enforce_keys	View

Protocols, Errors & Binaries

Polymorphism, failure idioms, and byte-level parsing — the three lessons that finish the language core.

#	Description	Link
13	Protocols — defprotocol/defimpl and derived implementations	View
14	Behaviours — @callback contracts and @impl dispatch	View
15	Error handling — raise/rescue/after, tagged tuples, custom exceptions	View
16	Binaries and sigils — bitstring parsing of a wire frame	View

Tooling

The AST, macros, tests, and property checks — the files that teach you how Elixir compiles and verifies itself.

#	Description	Link
17	Quote and unquote — inspecting the AST of real expressions	View
18	Custom macros — a trace/1 macro with hygiene	View
19	ExUnit and doctests — a test suite that runs in one script	View
20	Property tests — StreamData roundtrip properties	View

Concurrency & OTP

From raw spawn to supervised servers — the phase 4 pattern book in runnable form.

#	Description	Link
21	Spawn, send, receive — a raw process with a mailbox	View
22	Links and monitors — crash propagation and :DOWN messages	View
23	Tasks — async/await and bounded async_stream pools	View
24	Agents — atomic get/update state holders	View
25	GenServer — a complete key/value server with call/cast/info	View

Supervision & Shared State

Supervisors, dynamic children, registration, ETS, and telemetry — how systems stay up.

#	Description	Link
26	Supervisor — one_for_one tree with crash-loop protection	View
27	DynamicSupervisor — sessions started and stopped at runtime	View
28	Registry — named processes for per-user state	View
29	ETS — shared read/write tables and concurrent access	View
30	Telemetry — instrumenting a module with event handlers	View

Ecosystem

Ecto, Broadway, Nx, and Plug — single-file scripts made runnable with Mix.install/2 (network access needed on first run).

#	Description	Link
31	Ecto changesets — schema + validation pipeline, no database required	View
32	Broadway pipeline — a custom producer with back-pressure	View
33	Nx tensors — defn functions and a softmax	View
34	Plug pipeline — a minimal HTTP app on Bandit	View
35	Oban worker — a job definition (study demo: needs PostgreSQL)	View
36	Release config — application env read from runtime.exs (study demo)	View

How to run them. Stdlib demos need nothing but Elixir: elixir demo/core/06_pattern_matching.exs. Ecosystem demos (31–34) start with Mix.install/2 and fetch their dependencies from Hex on first run. Demos 35–36 need a PostgreSQL service (35) or a release build (36) and are written to be read and studied in the viewer. Larger multi-file study projects are on the Study Projects page.