[2025-01-02] Sync fork (#2)

* use OpenSans as fallback font on PRs from forks

* Fix typo

* Update reference from Rustonomicon to Rust Reference

The exercise refers to the "Data layout" section of the Rustonomicon, but now that section claims itself deprecated and redirects to the "Type layout" section of The Rust Reference.

* 05_ticket_v2 outro: correct comment on title (mainmatter#179)

Characters was meant to be bytes, this was missed in a former refactoring

* Change docstring: "when converted to `u8`"

Fixed docstring

* exercises 02_basic_calculator/04_panics: fix comma splice in panic message

* Update 08_overflow.md

if you read threw the profile docs it provides 4 profiles. https://doc.rust-lang.org/cargo/reference/profiles.html

* chore(ci): re-create book artifacts at the beginning of each month

* Update 08_overflow.md

Added some context.

* Update 11_clone.md (mainmatter#205)

typo in code

* format

* debug pandoc build

* fix reference to fallback font

* switch off Pandoc verbosity

* run Gravity on online PDF

* debug

* fix a superfluous word in a comment (mainmatter#217)

* fix a small typo in 11_locks.md (mainmatter#219)

* Fix typo in 03_leak.md (mainmatter#220)

Corrected a confusing sentence with double negative.

* Add install steps to the welcome page (mainmatter#196)

* Warn about the risks of using catch-all patterns (mainmatter#200)

* doc: update book 06_01_arrays (mainmatter#195)

* Update aliases

* Update redirects

* Formatting

* Link to the next tutored session in the methodology section

* Ignore dead code warnings until visibility has been explained (mainmatter#232)

* Format all manifests

* Don't mark Rust code snippets as runnable

* Showcase else-if (mainmatter#234)

* Give a more structure hint for iteration exercises (mainmatter#235)

* Clarify that both crate and super are keywords (mainmatter#236)

* Clarify Send-Sync relationship (mainmatter#237)

* Change if-else exercise to require an if-else (mainmatter#238)

* Avoid using a suffix (mainmatter#239)

---------

Co-authored-by: Marco Otte-Witte <marco.otte-witte@mainmatter.com>
Co-authored-by: Simon Morgan <sjm@sjm.io>
Co-authored-by: Luca Boschetto <61137723+LucaBoschetto@users.noreply.github.com>
Co-authored-by: iacri <49108209+iacri@users.noreply.github.com>
Co-authored-by: Henk Oordt <hd@oordt.dev>
Co-authored-by: Benjamin Tamasi <half2me@users.noreply.github.com>
Co-authored-by: Vincent Ging Ho Yim <cenviity@gmail.com>
Co-authored-by: Manuel Bichler <bichler@gmail.com>
Co-authored-by: Bartlomiej Dudzik <bartholomew.dudzik@gmail.com>
Co-authored-by: Robertino <48034748+rober-m@users.noreply.github.com>
Co-authored-by: dawe <dawedawe@posteo.de>
Co-authored-by: Will Bush <git@willbush.dev>
Co-authored-by: Daniel Wagner-Hall <dawagner@gmail.com>
Co-authored-by: Maor Levy <Atixx@users.noreply.github.com>
Co-authored-by: LukeMathWalker <20745048+LukeMathWalker@users.noreply.github.com>

Author: 16 people

.github/workflows/ci.yml

@@ -146,6 +146,23 @@ jobs:
       - run: |
           git diff --exit-code site/_redirects
 
+  gravity:
+    runs-on: ubuntu-latest
+    needs: [build]
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          path: book
+          pattern: online-pdf
+      - uses: pnpm/action-setup@v4
+        with:
+          version: 9
+      - run: ls -las ./book
+      - name: Run Gravity
+        run: pnpm dlx @gravityci/cli "./book/**/*"
+        env:
+          GRAVITY_TOKEN: ${{ secrets.GRAVITY_TOKEN }}
+
   formatter:
     runs-on: ubuntu-latest
     steps:

book/book.toml

@@ -18,6 +18,9 @@ after = ["exercise-linker"]
 [output.html]
 git-repository-url = "https://github.com/mainmatter/100-exercises-to-learn-rust"
 
+[output.html.playground]
+runnable = false
+
 [output.pandoc]
 optional = true
 hosted-html = "https://rust-exercises.com/100-exercises/"
@@ -49,8 +52,8 @@ sansfontoptions = [
 ]
 # You can get these fonts here: https://fonts.google.com/selection?query=noto+color+
 monofont = "Noto Sans Mono"
-mainfontfallback = ["Open Sans"]
-sansfontfallback = ["Open Sans"]
+mainfontfallback = ["Open Sans:style=Regular"]
+sansfontfallback = ["Open Sans:style=Regular"]
 monofontfallback = [
   "Noto Color Emoji:mode=harf",
 ]
@@ -90,8 +93,8 @@ sansfontoptions = [
 ]
 # You can get these fonts here: https://fonts.google.com/selection?query=noto+color+
 monofont = "Noto Sans Mono"
-mainfontfallback = ["Open Sans"]
-sansfontfallback = ["Open Sans"]
+mainfontfallback = ["Open Sans:style=Regular"]
+sansfontfallback = ["Open Sans:style=Regular"]
 monofontfallback = [
   "Noto Color Emoji:mode=harf",
 ]
@@ -121,8 +124,8 @@ metadata-file = "metadata.yml"
 [output.pandoc.profile.html.variables]
 # You can get these fonts here: https://fonts.google.com/selection?query=noto+color+
 monofont = "Noto Sans Mono"
-mainfontfallback = ["Open Sans"]
-sansfontfallback = ["Open Sans"]
+mainfontfallback = ["Open Sans:style=Regular"]
+sansfontfallback = ["Open Sans:style=Regular"]
 monofontfallback = [
   "Noto Color Emoji:mode=harf",
 ]

book/link2alias.json

@@ -1,5 +1,6 @@
 {
   "https://blog.acolyer.org/2019/05/28/cheri-abi/": "f2u",
+  "https://code.visualstudio.com": "f6c",
   "https://crates.io": "f4q",
   "https://crates.io/crates/cargo-modules": "f2n",
   "https://doc.rust-lang.org/book/ch03-02-data-types.html#integer-types": "ffr",
@@ -164,6 +165,7 @@
   "https://mainmatter.com/contact/": "ff2",
   "https://mainmatter.com/rust-consulting/": "fff",
   "https://marabos.nl/atomics/": "fxg",
+  "https://marketplace.visualstudio.com/items?itemName=matklad.rust-analyzer": "f6a",
   "https://nostarch.com/rust-rustaceans": "f6p",
   "https://owasp.org/www-community/vulnerabilities/Doubly_freeing_memory": "f2k",
   "https://owasp.org/www-community/vulnerabilities/Using_freed_memory": "f2s",
@@ -177,14 +179,17 @@
   "https://rust-lang.github.io/api-guidelines/naming.html#casing-conforms-to-rfc-430-c-case": "fze",
   "https://rust-lang.github.io/wg-async/vision/submitted_stories/status_quo/barbara_battles_buffered_streams.html": "f6w",
   "https://ryhl.io/blog/async-what-is-blocking/": "f6v",
+  "https://ti.to/mainmatter/rust-from-scratch-jan-2025": "fvf",
   "https://tokio.rs/tokio/tutorial/select": "f6n",
   "https://valgrind.org/docs/manual/dh-manual.html": "f2t",
   "https://veykril.github.io/tlborm/": "fz5",
   "https://without.boats/blog/the-scoped-task-trilemma/": "f67",
   "https://www.amazon.com/dp/B0DJ14KQQG/": "f6g",
+  "https://www.jetbrains.com/rust/": "f6d",
   "https://www.lpalmieri.com/": "ffv",
   "https://www.lpalmieri.com/posts/2020-12-11-zero-to-production-6-domain-modelling/": "f4t",
   "https://www.oreilly.com/library/view/programming-rust-2nd/9781492052586/": "f6y",
+  "https://www.rust-lang.org/tools/install": "f6j",
   "https://www.youtube.com/playlist?list=PLqbS7AVVErFirH9armw8yXlE6dacF-A6z": "f6l",
   "https://zero2prod.com": "ff8"
 }

book/src/01_intro/00_welcome.md

@@ -24,12 +24,12 @@ It has been designed to be interactive and hands-on.
 to be delivered in a classroom setting, over 4 days: each attendee advances
 through the lessons at their own pace, with an experienced instructor providing
 guidance, answering questions and diving deeper into the topics as needed.\
-If you're interested in attending one of our training sessions, or if you'd like to
-bring this course to your company, please [get in touch](https://mainmatter.com/contact/).
+You can sign up for the next tutored session on [our website](https://ti.to/mainmatter/rust-from-scratch-jan-2025).
+If you'd like to organise a private session for your company, please [get in touch](https://mainmatter.com/contact/).
 
-You can also follow the course on your own, but we recommend you find a friend or
+You can also take the courses on your own, but we recommend you find a friend or
 a mentor to help you along the way should you get stuck. You can
-also find solutions to all exercises in the
+find solutions for all exercises in the
 [`solutions` branch of the GitHub repository](https://github.com/mainmatter/100-exercises-to-learn-rust/tree/solutions).
 
 ## Formats
@@ -67,9 +67,18 @@ Each exercise is structured as a Rust package.
 The package contains the exercise itself, instructions on what to do (in `src/lib.rs`), and a test suite to
 automatically verify your solution.
 
-### `wr`, the workshop runner
+### Tools
 
-To verify your solutions, we've provided a tool that will guide you through the course.
+To work through this course, you'll need:
+
+- [**Rust**](https://www.rust-lang.org/tools/install)).
+  If `rustup` is already installed on your system, run `rustup update` (or another appropriate command depending on how you installed Rust on your system) to ensure you're running on the latest stable version.
+- _(Optional but recommended)_ An IDE with Rust autocompletion support.
+  We recommend one of the following:
+  - [RustRover](https://www.jetbrains.com/rust/);
+  - [Visual Studio Code](https://code.visualstudio.com) with the [`rust-analyzer`](https://marketplace.visualstudio.com/items?itemName=matklad.rust-analyzer) extension.
+
+To verify your solutions, we've also provided a tool to guide you through the course.
 It is the `wr` CLI (short for "workshop runner").
 Install it with:
 

book/src/02_basic_calculator/03_if_else.md

@@ -36,6 +36,38 @@ if number < 5 {
 }
 ```
 
+### `else if` clauses
+
+Your code drifts more and more to the right when you have multiple `if` expressions, one nested inside the other.
+
+```rust
+let number = 3;
+
+if number < 5 {
+    println!("`number` is smaller than 5");
+} else {
+    if number >= 3 {
+        println!("`number` is greater than or equal to 3, but smaller than 5");
+    } else {
+        println!("`number` is smaller than 3");
+    }
+}
+```
+
+You can use the `else if` keyword to combine multiple `if` expressions into a single one:
+
+```rust
+let number = 3;
+
+if number < 5 {
+    println!("`number` is smaller than 5");
+} else if number >= 3 {
+    println!("`number` is greater than or equal to 3, but smaller than 5");
+} else {
+    println!("`number` is smaller than 3");
+}
+```
+
 ## Booleans
 
 The condition in an `if` expression must be of type `bool`, a **boolean**.\

book/src/02_basic_calculator/08_overflow.md

@@ -80,8 +80,6 @@ The `bench` profile is the default profile used by `cargo bench`. The `bench` pr
 Use `dev` for iterative development and debugging, `release` for optimized production builds,\
 `test` for correctness testing, and `bench` for performance benchmarking.
 
-
-
 > "Have you built your project in release mode?" is almost a meme in the Rust community.\
 > It refers to developers who are not familiar with Rust and complain about its performance on
 > social media (e.g. Reddit, Twitter, etc.) before realizing they haven't built their project in

book/src/03_ticket_v1/03_modules.md

@@ -85,6 +85,9 @@ You can compose the path in various ways:
 - starting from the parent module, e.g. `super::my_function`
 - starting from the current module, e.g. `sub_module_1::MyStruct`
 
+Both `crate` and `super` are **keywords**.\
+`crate` refers to the root of the current crate, while `super` refers to the parent of the current module.
+
 Having to write the full path every time you want to refer to a type can be cumbersome.
 To make your life easier, you can introduce a `use` statement to bring the entity into scope.
 

book/src/04_traits/11_clone.md

@@ -56,7 +56,7 @@ that to `consumer` instead.\
 ## In memory
 
 Let's look at what happened in memory in the example above.
-When `let mut s: String::from("hello");` is executed, the memory looks like this:
+When `let mut s = String::from("hello");` is executed, the memory looks like this:
 
 ```text
                     s

book/src/05_ticket_v2/02_match.md

@@ -68,3 +68,11 @@ match status {
 ```
 
 The `_` pattern matches anything that wasn't matched by the previous patterns.
+
+<div class="warning">
+By using this catch-all pattern, you _won't_ get the benefits of compiler-driven refactoring.\
+If you add a new enum variant, the compiler _won't_ tell you that you're not handling it.
+
+If you're keen on correctness, avoid using catch-alls. Leverage the compiler to re-examine all matching sites and determine how new enum variants should be handled.
+
+</div>

book/src/06_ticket_management/01_arrays.md

@@ -21,6 +21,15 @@ let numbers: [u32; 3] = [1, 2, 3];
 This creates an array of 3 integers, initialized with the values `1`, `2`, and `3`.\
 The type of the array is `[u32; 3]`, which reads as "an array of `u32`s with a length of 3".
 
+If all array elements are the same, you can use a shorter syntax to initialize it:
+
+```rust
+// [ <value> ; <number of elements> ]
+let numbers: [u32; 3] = [1; 3];
+```
+
+`[1; 3]` creates an array of three elements, all equal to `1`.
+
 ### Accessing elements
 
 You can access elements of an array using square brackets: