Where Rust shines

A workshop to learn Java{,script} developers to write more robust code by showing how Rust forces you to do so.

Required environment

You need:

Rust, install the latest stable version via rustup, see installation and set-up instructions below;
A text editor with support for Rust, the recommendation is to use Visual Studo Code, see installation and set-up instructions below.
Java;
Maven.

Installing Rust

Run curl https://sh.rustup.rs -sSf | sh to install rustup.

For these exercises we'll use a nightly version of rust (it is quite common when developing Rust to use nightly for development and build for production with stable). Before carrying out the commands below (at least the last part with override) make sure to clone this repository and place yourself at the root.

git clone git@github.com:atorstling/where-rust-shines.git
cd where-rust-shines.git

Then proceed with installation

rustup install stable
rustup default stable
rustc --version
# Should print something similar to this:
# rustc 1.21.0 (3b72af97e 2017-10-09)

rustup install nightly-2017-10-15
# We'll add an override for this specific repository, so ensure you stand the root of it when running the command
rustup override set nightly
rustc --version
# Should print something similar this:
# rustc 1.22.0-nightly (7778906be 2017-10-14)

Installing Visual Studio Code for Rust

# If you are on macOS and have brew and brew cask:
brew cask install visual-studio-code

Otherwise, see the installation instructions.

Then:

Open Visual Studio Code (which will be referred to as vscode henceforth);
Press cmd+shift+p to open the Command Palette;
Write ext install and select the alternative Extensions: Install extensions;
Type Rust and install the alternative called Rust (rls);
Since you will be looking at Java-code as well, write Java and install Language Support for Java(TM) by Red Hat;

Since we have structured the project kind of as a monorepo, you need to enable support for Rust workspaces. To do this go to your settings in vscode (cmd+,) and add the following:

{
    "rust.unstable_features": true,
    "rust.workspace_mode": true
}

With this done open one of the Rust files (called main.rs) and you should see RLS: ... in the status bar at the bottom. Wait for RLS to set up properly and see that syntax highlighting and auto-completion work.

Verifying your environment

To verify your environment clone this repo (if you have not already done so) and navigate to it in your terminal.

# Go to the Java part of the task
$ cd tasks/happy/java

# Build it
$ mvn clean install && java -jar target/*.jar
...
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 3.984 s
[INFO] Finished at: 2017-10-16T16:57:50+02:00
[INFO] Final Memory: 22M/304M
[INFO] ------------------------------------------------------------------------
Hello World!

# Go the rust part of the task and build it
$ cd ../rust
$ cargo run
   Compiling happy v0.1.0 (file:///Users/mbark/repos/where-rust-shines/tasks/happy/rust)
    Finished dev [unoptimized + debuginfo] target(s) in 0.34 secs
     Running `target/debug/happy`
Hello, world!
Hello &'static str
Hello String::from
res_function gave rise to error: SomeError
This is how a struct looks: Struct { field: "", int32: -100, uint64: 1 }

If all of this works fine:

Open the project in your editor;
Open the file tasks/happy/rust/src/main.rs;
Uncomment the lines marked to verify that you got RLS working with compilation errors and auto-completion.

Tasks

The repository is separated into a number of tasks that all illustrate common and easy to make mistakes in Java. There is also a matching Rust-project that illustrates how Rust, through its focus on building robust software prevents these mistakes.

How to run a Rust task

Once you are standing in a rust directory with a Cargo.toml file, you can run the program with cargo run:

$ cargo run
Compiling npe v0.1.0 (file:///Users/alexandert/projects/private/where-rust-shines/tasks/npe/rust)
    Finished dev [unoptimized + debuginfo] target(s) in 0.36 secs
     Running `target/debug/npe`
Kalle
$

How to run a Java task

alext@smith:~/projects/where-rust-shines/tasks/npe/java$ mvn clean install && java -jar target/*.jar
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building npe 1.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ npe ---
[INFO] Deleting /home/alext/projects/where-rust-shines/tasks/npe/java/target
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ npe ---
[WARNING] Using platform encoding (UTF-8 actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] skip non existing resourceDirectory /home/alext/projects/where-rust-shines/tasks/npe/java/src/main/resources
[INFO]
[INFO] --- maven-compiler-plugin:3.6.0:compile (default-compile) @ npe ---
[INFO] Changes detected - recompiling the module!
[WARNING] File encoding has not been set, using platform encoding UTF-8, i.e. build is platform dependent!
[INFO] Compiling 1 source file to /home/alext/projects/where-rust-shines/tasks/npe/java/target/classes
[INFO]
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ npe ---
[WARNING] Using platform encoding (UTF-8 actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] skip non existing resourceDirectory /home/alext/projects/where-rust-shines/tasks/npe/java/src/test/resources
[INFO]
[INFO] --- maven-compiler-plugin:3.6.0:testCompile (default-testCompile) @ npe ---
[INFO] Changes detected - recompiling the module!
[WARNING] File encoding has not been set, using platform encoding UTF-8, i.e. build is platform dependent!
[INFO] Compiling 1 source file to /home/alext/projects/where-rust-shines/tasks/npe/java/target/test-classes
[INFO]
[INFO] --- maven-surefire-plugin:2.12.4:test (default-test) @ npe ---
[INFO] Surefire report directory: /home/alext/projects/where-rust-shines/tasks/npe/java/target/surefire-reports

-------------------------------------------------------
 T E S T S
-------------------------------------------------------
Running se.cygni.npe.AppTest
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.078 sec

Results :

Tests run: 1, Failures: 0, Errors: 0, Skipped: 0

[INFO]
[INFO] --- maven-jar-plugin:3.0.2:jar (default-jar) @ npe ---
[INFO] Building jar: /home/alext/projects/where-rust-shines/tasks/npe/java/target/npe-1.0-SNAPSHOT.jar
[INFO]
[INFO] --- maven-install-plugin:2.4:install (default-install) @ npe ---
[INFO] Installing /home/alext/projects/where-rust-shines/tasks/npe/java/target/npe-1.0-SNAPSHOT.jar to /home/alext/.m2/repository/se/cygni/npe/npe/1.0-SNAPSHOT/npe-1.0-SNAPSHOT.jar
[INFO] Installing /home/alext/projects/where-rust-shines/tasks/npe/java/pom.xml to /home/alext/.m2/repository/se/cygni/npe/npe/1.0-SNAPSHOT/npe-1.0-SNAPSHOT.pom
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 4.854 s
[INFO] Finished at: 2017-10-10T16:27:09+02:00
[INFO] Final Memory: 16M/128M
[INFO] ------------------------------------------------------------------------
Exception in thread "main" java.lang.NullPointerException
  at se.cygni.npe.App.cleanup(App.java:6)
  at se.cygni.npe.App.main(App.java:12)
alext@smith:~/projects/where-rust-shines/tasks/npe/java$

TODO

Lägg till pusselbitar till alla övningar (Båda)
Sy ihop det hela (Barkis)
Presentation: Rusts koncept (Torstling)
Presentation: Rust syntax (Barkis)
Presentation: Result & Option vs Exception & Mutable, Move semantics (ägandeskap) (Barkis)
En till övning kring ägandeskap (Barkis)
Presentation: trådning (Torstling)
Channels (Barkis)
std::sync::Arc (Torstling)

Dr-Horv/where-rust-shines