Learn Gleam by building a text adventure: explore rooms, collect items and bring a world to life through your commands. A practical journey from your first steps to types, testing and concurrency, with Glim as your guide.
Book in preparation. Subscribe for news about the English edition.
Coming soon
If you want to get updates for this book, provide your name and email:
Description
Your first adventure starts with a line of code
This book takes a project-based approach to learning Gleam. Start with a room and a few commands, then revisit the ideas behind your code and grow your adventure step by step.
Learn by building
The planned journey covers values and functions, custom types, pattern matching, lists and recursion, Result and Option, modules and packages. No previous programming experience is required: start with the project or read the fundamentals first.
From one room to a shared world
The planned contents include a command parser, saved games and automated tests. They then introduce processes, actors and supervision on the BEAM, before exploring JavaScript, a web server and interoperability with Erlang and Elixir.
With Glim by your side
A little will-o’-the-wisp accompanies you with hints and pointers to the chapters that explain each concept.
This edition is in preparation. The contents are provisional and may change during writing. Sales and preorders are not open yet. Subscribe to hear about its progress.
Content
Introduction
-
Introduction prepared
An introduction to the book’s approach, Glim and the learning journey.
Chapters
-
Hello, Glim… Gleam? to do
Install Erlang + Gleam, `gleam new`, `gleam run`, the shape of a program.
-
A room, a prompt, a command to do
Print a description, read a line from the keyboard, a loop, `case` on the command.
-
Rooms on a map to do
2–3 rooms as data (a custom type), north/south, tracking "where am I".
-
Loot, and a way to win to do
Items in a list, `take`/`inventory`, a win condition; a complete playable adventure.
-
Everything is a value to do
Everything is an expression, immutability, the basic types.
-
Functions, labels and the pipe to do
Arguments, labels, anonymous functions, `|>`, last expression is the return.
-
The compiler is on your side to do
Inference, the compiler as an ally, reading type errors.
-
Types you design yourself to do
The thing you used for rooms, properly; variants, constructors, records.
-
Every case covered to do
`case`, guards, exhaustiveness, destructuring.
-
There is no "for" loop to do
There is no `for` loop; the `list` module, folds, maps.
-
No null, no exceptions to do
No exceptions, no null; `use` for the happy path.
-
Organising code, adding packages to do
Organising code, `import`, a stdlib tour, adding a Hex dependency, `gleam.toml`.
-
The world, properly modelled to do
Rooms, exits, items and the player as well-made types; a world file.
-
From words to commands to do
From "take the rusty key" to a typed command; synonyms, error messages.
-
State that flows through to do
State as a value that flows; separating pure logic from I/O.
-
Writing the game to disk to do
Files, encoding/decoding JSON, `dynamic`/`decode`.
-
Tests that catch you to do
`gleeunit`, testing the pure logic, TDD of a feature.
-
Little processes, passing notes to do
What the BEAM is; `spawn`, send/receive; the actor mindset.
-
The world becomes an actor to do
The `actor` from `gleam_otp`; the world as an actor.
-
A world full of players to do
Several sessions talking to one shared world; a lobby.
-
Let it crash, then recover to do
"Let it crash", supervisors, restarts.
-
The same code, in a browser to do
Compile to JS, a minimal web front end, FFI to JS.
-
Serving the game over the web to do
`wisp`/`mist`, serving the adventure over HTTP/WebSocket.
-
Borrowing from Erlang and Elixir to do
The Erlang target, FFI, using an ecosystem library.
-
Give the engine away to do
Extract the engine as a library, docs, `gleam publish`, versioning.
-
Where to go from here to do
Bigger OTP, the community, ideas to keep hacking.
Information
Related books
If you want to understand the BEAM world under Gleam, here you go!
