Massively simplify getting started with Scala

joan38 · joan38 · commit b900ce8043b6 · 2025-03-02T23:23:39.000-05:00
diff --git a/_data/setup-scala.yml b/_data/setup-scala.yml
@@ -1,6 +1,2 @@
-linux-x86-64: curl -fL https://github.com/coursier/coursier/releases/latest/download/cs-x86_64-pc-linux.gz | gzip -d > cs && chmod +x cs && ./cs setup
-linux-arm64: curl -fL https://github.com/VirtusLab/coursier-m1/releases/latest/download/cs-aarch64-pc-linux.gz | gzip -d > cs && chmod +x cs && ./cs setup
-macOS-x86-64: curl -fL https://github.com/coursier/coursier/releases/latest/download/cs-x86_64-apple-darwin.gz | gzip -d > cs && chmod +x cs && (xattr -d com.apple.quarantine cs || true) && ./cs setup
-macOS-arm64: curl -fL https://github.com/VirtusLab/coursier-m1/releases/latest/download/cs-aarch64-apple-darwin.gz | gzip -d > cs && chmod +x cs && (xattr -d com.apple.quarantine cs || true) && ./cs setup
-macOS-brew: brew install coursier && coursier setup
-windows-link: https://github.com/coursier/coursier/releases/latest/download/cs-x86_64-pc-win32.zip
+macos-linux-cli: curl https://raw.githubusercontent.com/VirtusLab/scala-cli/refs/heads/main/scala-cli.sh > scala && chmod +x scala
+windows-cli: Invoke-WebRequest "https://raw.githubusercontent.com/VirtusLab/scala-cli/refs/heads/main/scala-cli.bat" -OutFile "scala.bat”
diff --git a/_overviews/getting-started/install-scala.md b/_overviews/getting-started/install-scala.md
@@ -33,48 +33,25 @@ The instructions below cover both Scala 2 and Scala 3.
 
 {% include inner-documentation-sections.html links=page.newcomer_resources %}
 
-##  Install Scala on your computer
+##  Install the Scala CLI
 
-Installing Scala means installing various command-line tools such as the Scala compiler and build tools.
-We recommend using the Scala installer tool "Coursier" that automatically installs all the requirements, but you can still manually install each tool.
+###  Install Scala in your project
 
-### Using the Scala Installer (recommended way)
-
-The Scala installer is a tool named [Coursier](https://get-coursier.io/docs/cli-overview), whose main command is named `cs`.
-It ensures that a JVM and standard Scala tools are installed on your system.
-Install it on your system with the following instructions.
+Download the Scala CLI launcher in your project directory:
 
 <!-- Display tabs for each OS -->
 {% tabs install-cs-setup-tabs class=platform-os-options %}
 
-<!-- macOS -->
-{% tab macOS for=install-cs-setup-tabs %}
+<!-- macOS/Linux -->
+{% tab macOS/Linux for=install-cs-setup-tabs %}
 Run the following command in your terminal, following the on-screen instructions:
-{% include code-snippet.html language='bash' codeSnippet=site.data.setup-scala.macOS-brew %}
-{% altDetails cs-setup-macos-nobrew  "Alternatively, if you don't use Homebrew:" %}
-  On the Apple Silicon (M1, M2, …) architecture:
-  {% include code-snippet.html language='bash' codeSnippet=site.data.setup-scala.macOS-arm64 %}
-  Otherwise, on the x86-64 architecture:
-  {% include code-snippet.html language='bash' codeSnippet=site.data.setup-scala.macOS-x86-64 %}
-{% endaltDetails %}
-{% endtab %}
-<!-- end macOS -->
-
-<!-- Linux -->
-{% tab Linux for=install-cs-setup-tabs %}
-  Run the following command in your terminal, following the on-screen instructions.
-
-  On the x86-64 architecture:
-  {% include code-snippet.html language='bash' codeSnippet=site.data.setup-scala.linux-x86-64 %}
-  Otherwise, on the ARM64 architecture:
-  {% include code-snippet.html language='bash' codeSnippet=site.data.setup-scala.linux-arm64 %}
+{% include code-snippet.html language='bash' codeSnippet=site.data.setup-scala.macos-linux-cli %}
 {% endtab %}
-<!-- end Linux -->
+<!-- end macOS/Linux -->
 
 <!-- Windows -->
 {% tab Windows for=install-cs-setup-tabs %}
-  Download and execute [the Scala installer for Windows]({{site.data.setup-scala.windows-link}})
-  based on Coursier, and follow the on-screen instructions.
+{% include code-snippet.html language='bash' codeSnippet=site.data.setup-scala.windows-cli %}
 {% endtab %}
 <!-- end Windows -->
 
@@ -83,71 +60,30 @@ Run the following command in your terminal, following the on-screen instructions
   <noscript>
     <p><span style="font-style:italic;">JavaScript is disabled, click the tab relevant for your OS.</span></p>
   </noscript>
-  Follow the documentation from Coursier on
-    [how to install and run `cs setup`](https://get-coursier.io/docs/cli-installation).
+  Follow the documentation from the Scala CLI on
+    [how to install and run `scala`](https://scala-cli.virtuslab.org/install).
 {% endtab %}
 <!-- end Other -->
 
 {% endtabs %}
 <!-- End tabs -->
 
-> <i class="fa fa-info"></i>&nbsp;&nbsp; You may need to restart your terminal, log out,
-> or reboot in order for the changes to take effect.
-{: .help-info}
-
-<!-- Alternative Detail - test the `scala` command -->
-{% altDetails testing-your-setup 'Testing your setup' %}
-Check your setup with the command `scala -version`, which should output:
-```bash
-$ scala -version
-Scala code runner version: 1.4.3
-Scala version (default): {{site.scala-3-version}}
-```
-{% endaltDetails %}
-<!-- end Alternative Detail -->
-
-
-Along with managing JVMs, `cs setup` also installs useful command-line tools:
-
-| Commands | Description |
-|----------|-------------|
-| `scalac` | the Scala compiler |
-| `scala`, `scala-cli` | [Scala CLI](https://scala-cli.virtuslab.org), interactive toolkit for Scala |
-| `sbt`, `sbtn` | The [sbt](https://www.scala-sbt.org/) build tool |
-| `amm` | [Ammonite](https://ammonite.io/) is an enhanced REPL |
-| `scalafmt` | [Scalafmt](https://scalameta.org/scalafmt/) is the Scala code formatter |
-
-For more information about `cs`, read
-[coursier-cli documentation](https://get-coursier.io/docs/cli-overview).
-
-> `cs setup` installs the Scala 3 compiler and runner by default (the `scalac` and
-> `scala` commands, respectively). Whether you intend to use Scala 2 or 3,
-> this is usually not an issue because most projects use a build tool that will
-> use the correct version of Scala irrespective of the one installed "globally".
-> Nevertheless, you can always launch a specific version of Scala using
-> ```
-> $ cs launch scala:{{ site.scala-version }}
-> $ cs launch scalac:{{ site.scala-version }}
-> ```
-> If you prefer Scala 2 to be run by default, you can force that version to be installed with:
-> ```
-> $ cs install scala:{{ site.scala-version }} scalac:{{ site.scala-version }}
-> ```
-
-### ...or manually
-
-You only need two tools to compile, run, test, and package a Scala project: Java 8 or 11,
-and Scala CLI.
-To install them manually:
-
-1. if you don't have Java 8 or 11 installed, download
-   Java from [Oracle Java 8](https://www.oracle.com/java/technologies/javase-jdk8-downloads.html), [Oracle Java 11](https://www.oracle.com/java/technologies/javase-jdk11-downloads.html),
-   or [AdoptOpenJDK 8/11](https://adoptopenjdk.net/). Refer to [JDK Compatibility](/overviews/jdk-compatibility/overview.html) for Scala/Java compatibility detail.
-1. Install [Scala CLI](https://scala-cli.virtuslab.org/install)
+We recommend committing the scala executable together with your code so that
+everyone working on the project can compile and run the code without needing to install anything (not even Java).
+
+### ...or/and install Scala on your computer
+
+Follow the documentation from the Scala CLI on
+[how to install and run `scala`](https://scala-cli.virtuslab.org/install).
 
 ## Using the Scala CLI
 
-In a directory of your choice, which we will call `<project-dir>`, create a file named `hello.scala` with the following code:
+This section assumes you downloaded the Scala CLI launcher in a directory of your choice, which we will call
+`<project-dir>`.
+If you installed the Scala CLI on your computer (globally) instead of in your `<project-dir>`, you should run the
+following commands with `scala` instead of `./scala`.
+
+Create a file named `hello.scala` with the following code:
 ```scala
 //> using scala {{site.scala-3-version}}
 
@@ -161,10 +97,10 @@ the entry point in program execution. The method's type is `Unit`, which means i
 can be thought of as an analogue to the `void` keyword found in other languages. The `println` method will print the `"Hello, World!"`
 string to standard output.
 
-To run the program, execute `scala run hello.scala` command from a terminal, within the `<project-dir>` directory. The file will be compiled and executed, with console output
+To run the program, execute `./scala run hello.scala` command from a terminal, within the `<project-dir>` directory. The file will be compiled and executed, with console output
 similar to following:
 ```
-$ scala run hello.scala
+$ ./scala run hello.scala
 Compiling project (Scala {{site.scala-3-version}}, JVM (20))
 Compiled project (Scala {{site.scala-3-version}}, JVM (20))
 Hello, World!
@@ -187,7 +123,7 @@ the content of the `name` argument.
 
 To pass the arguments when executing the program, put them after `--`:
 ```
-$ scala run hello.scala -- Gabriel
+$ ./scala run hello.scala -- Gabriel
 Compiling project (Scala {{site.scala-3-version}}, JVM (20))
 Compiled project (Scala {{site.scala-3-version}}, JVM (20))
 Hello, Gabriel!
@@ -202,7 +138,7 @@ We use the [os-lib](https://github.com/com-lihaoyi/os-lib) library from the [Sca
 for that purpose. A dependency on the library can be added with the `//> using` directive. Put the following code in `counter.scala`.
 ```scala
 //> using scala {{site.scala-3-version}}
-//> using dep "com.lihaoyi::os-lib:0.10.7"
+//> using dep "com.lihaoyi::os-lib:0.11.4"
 
 @main
 def countFiles(): Unit =
@@ -216,7 +152,7 @@ sequence of paths.
 
 Execute the program. The dependency will be automatically downloaded. The execution should result in a similar output:
 ```
-$ scala run counter.scala
+$ ./scala run counter.scala
 Compiling project (Scala {{site.scala-3-version}}, JVM (20))
 Compiled project (Scala {{site.scala-3-version}}, JVM (20))
 4
@@ -241,16 +177,16 @@ This program is identical to the one above. However, other toolkit libraries wil
 
 ### Using the REPL
 
-You can execute code interactively using the REPL provided by the `scala` command. Execute `scala` in the console without any arguments.
+You can execute code interactively using the REPL provided by the `scala` command. Execute `./scala` in the console without any arguments.
 ```
-$ scala
+$ ./scala
 Welcome to Scala {{site.scala-3-version}} (20-ea, Java OpenJDK 64-Bit Server VM).
 Type in expressions for evaluation. Or try :help.
 
 scala>
 ```
 
-Write a line of code to be executed and press enter.
+Write a line of code to be executed and press enter:
 ```
 scala> println("Hello, World!")
 Hello, World!
@@ -266,7 +202,7 @@ val i: Int = 1
 scala>
 ```
 
-A new value of type `Int` has been created. If you provide an expression that can be evaluated, its result will be stored in an automatically created value.
+A new value of type `Int` has been created. If you provide an expression that can be evaluated, its result will be stored in an automatically created value:
 ```
 scala> i + 3
 val res0: Int = 4
