Ziglings

⚠️ Ziglings has moved from GitHub to Codeberg!

You are looking at the current Ziglings repo if you are viewing this at https://codeberg.org/ziglings/exercises/

You can also use the handy URL https://ziglings.org to get here!

---

Welcome to Ziglings! This project contains a series of tiny broken programs (and one nasty surprise). By fixing them, you'll learn how to read and write Zig code.

Those broken programs need your help! (You'll also save the planet from evil aliens and help some friendly elephants stick together, which is very sweet of you.)

This project was directly inspired by the brilliant and fun rustlings project for the Rust language. Indirect inspiration comes from Ruby Koans and the Little LISPer/Little Schemer series of books.

Intended Audience

This will probably be difficult if you've never programmed before. But no specific programming experience is required. And in particular, you are not expected to have any prior experience with "systems programming" or a "systems" level language such as C.

Each exercise is self-contained and self-explained. However, you're encouraged to also check out these Zig language resources for more detail:

• https://ziglang.org/learn/
• https://ziglearn.org/
• https://ziglang.org/documentation/master/

Also, the Zig community is incredibly friendly and helpful!

Getting Started

Install a development build of the Zig compiler. (See the "master" section of the downloads page.)

Verify the installation and build number of zig like so:

$ zig version
0.12.0-dev.xxxx+xxxxxxxxx

Clone this repository with Git:

$ git clone https://ziglings.org
$ cd ziglings.org

Then run zig build and follow the instructions to begin!

$ zig build

Note: The output of Ziglings is the unaltered output from the Zig compiler. Part of the purpose of Ziglings is to acclimate you to reading these.

A Note About Versions

The Zig language is under very active development. In order to be current, Ziglings tracks development builds of the Zig compiler rather than versioned release builds. The last stable release was 0.11.0, but Ziglings needs a dev build with pre-release version "0.12.0" and a build number at least as high as that shown in the example version check above.

It is likely that you'll download a build which is greater than the minimum.

Once you have a build of the Zig compiler that works with Ziglings, they'll continue to work together. But keep in mind that if you update one, you may need to also update the other.

Version Changes

Version-0.11.0-dev.4246+71dfce31b

• 2023-06-26 zig 0.11.0-dev.4246 - changes in compile step (now it can be null)
• 2023-06-26 zig 0.11.0-dev.3853 - removal of destination type from all cast builtins
• 2023-06-20 zig 0.11.0-dev.3747 - @enumToInt is now @intFromEnum and @intToFloat is now @floatFromInt
• 2023-05-25 zig 0.11.0-dev.3295 - std.debug.TTY is now std.io.tty
• 2023-04-30 zig 0.11.0-dev.2704 - use of the new std.Build.ExecutableOptions.link_libc field
• 2023-04-12 zig 0.11.0-dev.2560 - changes in std.Build - remove run() and install()
• 2023-04-07 zig 0.11.0-dev.2401 - fixes of the new build system - see #212
• 2023-02-21 zig 0.11.0-dev.2157 - changes in build system - new: parallel processing of the build steps
• 2023-02-21 zig 0.11.0-dev.1711 - changes in for loops - new: Multi-Object For-Loops + Struct-of-Arrays
• 2023-02-12 zig 0.11.0-dev.1638 - changes in std.Build cache_root now returns a directory struct
• 2023-02-04 zig 0.11.0-dev.1568 - changes in std.Build (combine std.build and std.build.Builder into std.Build)
• 2023-01-14 zig 0.11.0-dev.1302 - changes in @addWithOverflow (now returns a tuple) and @typeInfo; temporary disabled async functionality
• 2022-09-09 zig 0.10.0-dev.3978 - change in NativeTargetInfo.detect in build
• 2022-09-06 zig 0.10.0-dev.3880 - Ex 074 correctly fails again: comptime array len
• 2022-08-29 zig 0.10.0-dev.3685 - @typeName() output change, stage1 req. for async
• 2022-07-31 zig 0.10.0-dev.3385 - std lib string fmt() option changes
• 2022-03-19 zig 0.10.0-dev.1427 - method for getting sentinel of type changed
• 2021-12-20 zig 0.9.0-dev.2025 - c_void is now anyopaque
• 2021-06-14 zig 0.9.0-dev.137 - std.build.Id .Custom is now .custom
• 2021-04-21 zig 0.8.0-dev.1983 - std.fmt.format() any format string required
• 2021-02-12 zig 0.8.0-dev.1065 - std.fmt.format() s (string) format string required

Advanced Usage

It can be handy to check just a single exercise:

zig build -Dn=19

You can also run without checking for correctness:

zig build -Dn=19 test

Or skip the build system entirely and interact directly with the compiler if you're into that sort of thing:

zig run exercises/001_hello.zig

Calling all wizards: To prepare an executable for debugging, install it to zig-cache/bin with:

zig build -Dn=19 install

To get a list of all possible options, run:

zig build -Dn=19 -l

  install          Install 019_functions2.zig to prefix path
  uninstall        Uninstall 019_functions2.zig from prefix path
  test             Run 019_functions2.zig without checking output
  ...

What's Covered

The primary goal for Ziglings is to cover the core Zig language.

It would be nice to cover the Standard Library as well, but this is currently challenging because the stdlib is evolving even faster than the core language (and that's saying something!). Not only would stdlib coverage change very rapidly, some exercises might even cease to be relevant entirely.

Having said that, there are some stdlib features that are probably here to stay or are so important to understand that they are worth the extra effort to keep current.

Conspicuously absent from Ziglings are a lot of string manipulation exercises. This is because Zig itself largely avoids dealing with strings. Hopefully there will be an obvious way to address this in the future. The Ziglings crew loves strings!

Zig Core Language

• Hello world (main needs to be public)
• Importing standard library
• Assignment
• Arrays
• Strings
• If
• While
• For
• Functions
• Errors (error/try/catch/if-else-err)
• Defer (and errdefer)
• Switch
• Unreachable
• Enums
• Structs
• Pointers
• Optionals
• Struct methods
• Slices
• Many-item pointers
• Unions
• Numeric types (integers, floats)
• Labelled blocks and loops
• Loops as expressions
• Builtins
• Inline loops
• Comptime
• Sentinel termination
• Quoted identifiers @""
• Anonymous structs/tuples/lists
• Async <--- ironically awaiting upstream Zig updates
• Interfaces
• Bit manipulation
• Working with C
• Interfaces part 2

Zig Standard Library

• String formatting
• Testing
• Tokenization

Contributing

Contributions are very welcome! I'm writing this to teach myself and to create the learning resource I wished for. There will be tons of room for improvement:

• Wording of explanations
• Idiomatic usage of Zig
• Additional exercises

Please see CONTRIBUTING in this repo for the full details.