Format all Markdown files with dprint

This is the result of running `dprint fmt` after making two temporary
changes:

- removing `src/` from the list of excluded directories,
- removing the `rustfmt` configuration.

The effect of the first change is that we normalize the formatting of
all Markdown files. The effect of the second is that we avoid
reformatting code blocks in the Markdown files. I want to reformat the
Rust code in a follow-up step since some of the changes seem
unnecessary or undesirable.

Thanks to mdbook-i18n-helpers 0.2, the POT file is nearly unchanged
after this, meaning that all existing translations remain valid. A few
messages were changed because of stray whitespace characters:

     msgid ""
     "Slices always borrow from another object. In this example, `a` has to remain "
    -"'alive' (in scope) for at least as long as our slice. "
    +"'alive' (in scope) for at least as long as our slice."
     msgstr ""

I have not updated CI to require perfectly formatted files. I think
doing so might be annoying since it makes it much harder to submit
small fixes directly from the GitHub editor. So for now, I suggest
that we simply run `dprint` by hand every few weeks.

If dprint/check#11 is fixed so that `dprint` can annotate the lines
that need fixing directly, then I think we can consider more strict
formatting checks.

src/SUMMARY.md

@@ -1,6 +1,7 @@
-
 <!-- Keep first page as index.md to avoid giving it two names. -->
+
 [Welcome to Comprehensive Rust 🦀](index.md)
+
 - [Running the Course](running-the-course.md)
   - [Course Structure](running-the-course/course-structure.md)
   - [Keyboard Shortcuts](running-the-course/keyboard-shortcuts.md)
@@ -10,8 +11,7 @@
   - [Code Samples](cargo/code-samples.md)
   - [Running Cargo Locally](cargo/running-locally.md)
 
-
-----
+---
 
 # Day 1: Morning
 
@@ -63,7 +63,7 @@
   - [Exercise: Elevator Events](user-defined-types/exercise.md)
     - [Solution](user-defined-types/solution.md)
 
-----
+---
 
 # Day 2: Morning
 
@@ -112,7 +112,7 @@
   - [Exercise: ROT13](std-traits/exercise.md)
     - [Solution](std-traits/solution.md)
 
-----
+---
 
 # Day 3: Morning
 
@@ -202,7 +202,7 @@
 
 # Android
 
-----
+---
 
 - [Welcome](android.md)
 - [Setup](android/setup.md)
@@ -237,11 +237,9 @@
   - [With Java](android/interoperability/java.md)
 - [Exercises](exercises/android/morning.md)
 
-
-
 # Chromium
 
-----
+---
 
 - [Welcome](chromium.md)
 - [Setup](chromium/setup.md)
@@ -260,8 +258,8 @@
   - [Example bindings](chromium/interoperability-with-cpp/example-bindings.md)
   - [Limitations of CXX](chromium/interoperability-with-cpp/limitations-of-cxx.md)
   - [CXX error handling](chromium/interoperability-with-cpp/error-handling.md)
-      - [Error handling: QR example](chromium/interoperability-with-cpp/error-handling-qr.md)
-      - [Error handling: PNG example](chromium/interoperability-with-cpp/error-handling-png.md)
+    - [Error handling: QR example](chromium/interoperability-with-cpp/error-handling-qr.md)
+    - [Error handling: PNG example](chromium/interoperability-with-cpp/error-handling-png.md)
   - [Using CXX in Chromium](chromium/interoperability-with-cpp/using-cxx-in-chromium.md)
   - [Exercise](exercises/chromium/interoperability-with-cpp.md)
 - [Adding third party crates](chromium/adding-third-party-crates.md)
@@ -279,10 +277,9 @@
   - [Exercise](exercises/chromium/third-party.md)
 - [Bringing it together - Exercise](exercises/chromium/bringing-it-together.md)
 
-
 # Bare Metal: Morning
 
-----
+---
 
 - [Welcome](bare-metal.md)
 - [`no_std`](bare-metal/no_std.md)
@@ -331,10 +328,9 @@
   - [RTC Driver](exercises/bare-metal/rtc.md)
   - [Solutions](exercises/bare-metal/solutions-afternoon.md)
 
-
 # Concurrency: Morning
 
-----
+---
 
 - [Welcome](concurrency.md)
 - [Threads](concurrency/threads.md)
@@ -377,10 +373,9 @@
   - [Broadcast Chat Application](exercises/concurrency/chat-app.md)
   - [Solutions](exercises/concurrency/solutions-afternoon.md)
 
-
 # Final Words
 
-----
+---
 
 - [Thanks!](thanks.md)
 - [Glossary](glossary.md)

src/android.md

@@ -2,11 +2,12 @@
 course: Android
 session: Android
 ---
+
 # Welcome to Rust in Android
 
-Rust is supported for system software on Android. This means that
-you can write new services, libraries, drivers or even firmware in Rust
-(or improve existing code as needed).
+Rust is supported for system software on Android. This means that you can write
+new services, libraries, drivers or even firmware in Rust (or improve existing
+code as needed).
 
 > We will attempt to call Rust from one of your own projects today. So try to
 > find a little corner of your code base where we can move some lines of code to
@@ -15,15 +16,19 @@ you can write new services, libraries, drivers or even firmware in Rust
 
 <details>
 
-The speaker may mention any of the following given the increased use of Rust
-in Android:
+The speaker may mention any of the following given the increased use of Rust in
+Android:
 
-- Service example: [DNS over HTTP](https://security.googleblog.com/2022/07/dns-over-http3-in-android.html)
+- Service example:
+  [DNS over HTTP](https://security.googleblog.com/2022/07/dns-over-http3-in-android.html)
 
-- Libraries: [Rutabaga Virtual Graphics Interface](https://crosvm.dev/book/appendix/rutabaga_gfx.html)
+- Libraries:
+  [Rutabaga Virtual Graphics Interface](https://crosvm.dev/book/appendix/rutabaga_gfx.html)
 
-- Kernel Drivers: [Binder](https://lore.kernel.org/rust-for-linux/[email protected]/)
+- Kernel Drivers:
+  [Binder](https://lore.kernel.org/rust-for-linux/[email protected]/)
 
-- Firmware: [pKVM firmware](https://security.googleblog.com/2023/10/bare-metal-rust-in-android.html)
+- Firmware:
+  [pKVM firmware](https://security.googleblog.com/2023/10/bare-metal-rust-in-android.html)
 
 </details>

src/android/aidl.md

@@ -1,7 +1,9 @@
 # AIDL
 
-The [Android Interface Definition Language
-(AIDL)](https://developer.android.com/guide/components/aidl) is supported in Rust:
+The
+[Android Interface Definition Language
+(AIDL)](https://developer.android.com/guide/components/aidl) is supported in
+Rust:
 
-* Rust code can call existing AIDL servers,
-* You can create new AIDL servers in Rust.
+- Rust code can call existing AIDL servers,
+- You can create new AIDL servers in Rust.

src/android/aidl/client.md

@@ -2,13 +2,13 @@
 
 Finally, we can create a Rust client for our new service.
 
-*birthday_service/src/client.rs*:
+_birthday_service/src/client.rs_:
 
 ```rust,ignore
 {{#include birthday_service/src/client.rs:main}}
 ```
 
-*birthday_service/Android.bp*:
+_birthday_service/Android.bp_:
 
 ```javascript
 {{#include birthday_service/Android.bp:birthday_client}}

src/android/aidl/implementation.md

@@ -2,13 +2,13 @@
 
 We can now implement the AIDL service:
 
-*birthday_service/src/lib.rs*:
+_birthday_service/src/lib.rs_:
 
 ```rust,ignore
 {{#include birthday_service/src/lib.rs:IBirthdayService}}
 ```
 
-*birthday_service/Android.bp*:
+_birthday_service/Android.bp_:
 
 ```javascript
 {{#include birthday_service/Android.bp:libbirthdayservice}}

src/android/aidl/interface.md

@@ -2,13 +2,13 @@
 
 You declare the API of your service using an AIDL interface:
 
-*birthday_service/aidl/com/example/birthdayservice/IBirthdayService.aidl*:
+_birthday_service/aidl/com/example/birthdayservice/IBirthdayService.aidl_:
 
 ```java
 {{#include birthday_service/aidl/com/example/birthdayservice/IBirthdayService.aidl:IBirthdayService}}
 ```
 
-*birthday_service/aidl/Android.bp*:
+_birthday_service/aidl/Android.bp_:
 
 ```javascript
 {{#include birthday_service/aidl/Android.bp}}

src/android/aidl/server.md

@@ -2,13 +2,13 @@
 
 Finally, we can create a server which exposes the service:
 
-*birthday_service/src/server.rs*:
+_birthday_service/src/server.rs_:
 
 ```rust,ignore
 {{#include birthday_service/src/server.rs:main}}
 ```
 
-*birthday_service/Android.bp*:
+_birthday_service/Android.bp_:
 
 ```javascript
 {{#include birthday_service/Android.bp:birthday_server}}

src/android/build-rules.md

@@ -19,13 +19,20 @@ We will look at `rust_binary` and `rust_library` next.
 
 Additional items speaker may mention:
 
-- Cargo is not optimized for multi-language repos, and also downloads packages from the internet.
+- Cargo is not optimized for multi-language repos, and also downloads packages
+  from the internet.
 
-- For compliance and performance, Android must have crates in-tree.  It must also interop with C/C++/Java code.  Soong fills that gap.
+- For compliance and performance, Android must have crates in-tree. It must also
+  interop with C/C++/Java code. Soong fills that gap.
 
-- Soong has many similarities to Bazel, which is the open-source variant of Blaze (used in google3).
+- Soong has many similarities to Bazel, which is the open-source variant of
+  Blaze (used in google3).
 
-- There is a plan to transition [Android](https://source.android.com/docs/setup/build/bazel/introduction), [ChromeOS](https://chromium.googlesource.com/chromiumos/bazel/), and [Fuchsia](https://source.android.com/docs/setup/build/bazel/introduction) to Bazel.
+- There is a plan to transition
+  [Android](https://source.android.com/docs/setup/build/bazel/introduction),
+  [ChromeOS](https://chromium.googlesource.com/chromiumos/bazel/), and
+  [Fuchsia](https://source.android.com/docs/setup/build/bazel/introduction) to
+  Bazel.
 
 - Learning Bazel-like build rules is useful for all Rust OS developers.
 

src/android/build-rules/library.md

@@ -4,8 +4,8 @@ You use `rust_library` to create a new Rust library for Android.
 
 Here we declare a dependency on two libraries:
 
-* `libgreeting`, which we define below,
-* `libtextwrap`, which is a crate already vendored in
+- `libgreeting`, which we define below,
+- `libtextwrap`, which is a crate already vendored in
   [`external/rust/crates/`][crates].
 
 [crates]: https://cs.android.com/android/platform/superproject/+/master:external/rust/crates/

src/android/interoperability.md

@@ -3,8 +3,8 @@
 Rust has excellent support for interoperability with other languages. This means
 that you can:
 
-* Call Rust functions from other languages.
-* Call functions written in other languages from Rust.
+- Call Rust functions from other languages.
+- Call functions written in other languages from Rust.
 
 When you call functions in a foreign language we say that you're using a
 _foreign function interface_, also known as FFI.

src/android/interoperability/cpp/android-build-cpp.md

@@ -17,12 +17,12 @@ cc_library_static {
 
 <details>
 
-* Point out that `libcxx_test_bridge_header` and `libcxx_test_bridge_code` are
+- Point out that `libcxx_test_bridge_header` and `libcxx_test_bridge_code` are
   the dependencies for the CXX-generated C++ bindings. We'll show how these are
   setup on the next slide.
-* Note that you also need to depend on the `cxx-bridge-header` library in order
+- Note that you also need to depend on the `cxx-bridge-header` library in order
   to pull in common CXX definitions.
-* Full docs for using CXX in Android can be found in [the Android docs]. You may
+- Full docs for using CXX in Android can be found in [the Android docs]. You may
   want to share that link with the class so that students know where they can
   find these instructions again in the future.
 

src/android/interoperability/cpp/android-cpp-genrules.md

@@ -26,9 +26,9 @@ genrule {
 
 <details>
 
-* The `cxxbridge` tool is a standalone tool that generates the C++ side of the
+- The `cxxbridge` tool is a standalone tool that generates the C++ side of the
   bridge module. It is included in Android and available as a Soong tool.
-* By convention, if your Rust source file is `lib.rs` your header file will be
+- By convention, if your Rust source file is `lib.rs` your header file will be
   named `lib.rs.h` and your source file will be named `lib.rs.cc`. This naming
   convention isn't enforced, though.
 

src/android/interoperability/cpp/bridge.md

@@ -10,14 +10,14 @@ a Rust module annotated with the `#[cxx::bridge]` attribute macro.
 
 <details>
 
-* The bridge is generally declared in an `ffi` module within your crate.
-* From the declarations made in the bridge module, CXX will generate matching
+- The bridge is generally declared in an `ffi` module within your crate.
+- From the declarations made in the bridge module, CXX will generate matching
   Rust and C++ type/function definitions in order to expose those items to both
   languages.
-* To view the generated Rust code, use [cargo-expand] to view the expanded proc
+- To view the generated Rust code, use [cargo-expand] to view the expanded proc
   macro. For most of the examples you would use `cargo expand ::ffi` to expand
   just the `ffi` module (though this doesn't apply for Android projects).
-* To view the generated C++ code, look in `target/cxxbridge`.
+- To view the generated C++ code, look in `target/cxxbridge`.
 
 [cargo-expand]: https://github.com/dtolnay/cargo-expand
 

src/android/interoperability/cpp/cpp-bridge.md

@@ -43,10 +43,10 @@ impl BlobstoreClient {
 
 <details>
 
-* The programmer does not need to promise that the signatures they have typed in
+- The programmer does not need to promise that the signatures they have typed in
   are accurate. CXX performs static assertions that the signatures exactly
   correspond with what is declared in C++.
-* `unsafe extern` blocks allow you to declare C++ functions that are safe to
+- `unsafe extern` blocks allow you to declare C++ functions that are safe to
   call from Rust.
 
 </details>

src/android/interoperability/cpp/cpp-exception.md

@@ -6,9 +6,9 @@
 
 <details>
 
-* C++ functions declared to return a `Result` will catch any thrown exception on
+- C++ functions declared to return a `Result` will catch any thrown exception on
   the C++ side and return it as an `Err` value to the calling Rust function.
-* If an exception is thrown from an extern "C++" function that is not declared
+- If an exception is thrown from an extern "C++" function that is not declared
   by the CXX bridge to return `Result`, the program calls C++'s
   `std::terminate`. The behavior is equivalent to the same exception being
   thrown through a `noexcept` C++ function.

src/android/interoperability/cpp/rust-bridge.md

@@ -6,9 +6,9 @@
 
 <details>
 
-* Items declared in the `extern "Rust"` reference items that are in scope in the
+- Items declared in the `extern "Rust"` reference items that are in scope in the
   parent module.
-* The CXX code generator uses your `extern "Rust"` section(s) to produce a C++
+- The CXX code generator uses your `extern "Rust"` section(s) to produce a C++
   header file containing the corresponding C++ declarations. The generated
   header has the same path as the Rust source file containing the bridge, except
   with a .rs.h file extension.

src/android/interoperability/cpp/rust-result.md

@@ -6,12 +6,12 @@
 
 <details>
 
-* Rust functions that return `Result` are translated to exceptions on the C++
+- Rust functions that return `Result` are translated to exceptions on the C++
   side.
-* The exception thrown will always be of type `rust::Error`, which primarily
+- The exception thrown will always be of type `rust::Error`, which primarily
   exposes a way to get the error message string. The error message will come
   from the error type's `Display` impl.
-* A panic unwinding from Rust to C++ will always cause the process to
+- A panic unwinding from Rust to C++ will always cause the process to
   immediately terminate.
 
 </details>

src/android/interoperability/cpp/shared-enums.md

@@ -18,7 +18,7 @@ Generated C++:
 
 <details>
 
-* On the Rust side, the code generated for shared enums is actually a struct
+- On the Rust side, the code generated for shared enums is actually a struct
   wrapping a numeric value. This is because it is not UB in C++ for an enum
   class to hold a value different from all of the listed variants, and our Rust
   representation needs to have the same behavior.

src/android/interoperability/cpp/shared-types.md

@@ -6,8 +6,8 @@
 
 <details>
 
-* Only C-like (unit) enums are supported.
-* A limited number of traits are supported for `#[derive()]` on shared types.
+- Only C-like (unit) enums are supported.
+- A limited number of traits are supported for `#[derive()]` on shared types.
   Corresponding functionality is also generated for the C++ code, e.g. if you
   derive `Hash` also generates an implementation of `std::hash` for the
   corresponding C++ type.