fix: ensure everything works and instructions updated

.github/workflows/ci.yml

@@ -16,27 +16,17 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout current branch (full)
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
         with:
           fetch-depth: 0
 
       - name: Setup Java
-        uses: actions/setup-java@v2
+        uses: actions/setup-java@v3
         with:
           distribution: temurin
           java-version: ${{ matrix.java-version }}
 
-      - name: Cache sbt
-        uses: actions/cache@v2
-        with:
-          path: |
-            ~/.sbt
-            ~/.ivy2/cache
-            ~/.coursier/cache/v1
-            ~/.cache/coursier/v1
-            ~/AppData/Local/Coursier/Cache/v1
-            ~/Library/Caches/Coursier/v1
-          key: ${{ runner.os }}-sbt-cache-v2-${{ hashFiles('**/*.sbt') }}-${{ hashFiles('project/build.properties') }}
+      - uses: coursier/cache-action@v6
 
       - name: Run project
-        run: ./mill root.run
+        run: ./mill examples.run

.mill-version

@@ -0,0 +1 @@
+0.10.5

README.md

@@ -1,66 +1,29 @@
 # Example mill project that compiles using Scala 3
 
-**NOTE**: Scala 3 support in mill is experimental. For now, sbt remains the
-preferred option. See https://github.com/scala/scala3-example-project for an
-example sbt project.
-
 ## Usage
 
-This is a normal mill project. You can compile code with `mill root.compile` and run it
-with `mill root.run`, `mill -i root.console` will start a Scala 3 REPL.
+This is a normal mill project. You can compile code with `mill examples.compile` and run it
+with `mill examples.run`, `mill -i examples.console` will start a Scala 3 REPL.
 
 ### IDE support
 
-Scala 3 comes built-in with IDE support, unfortunately this support is only
-available using sbt and not mill for now, see http://dotty.epfl.ch/docs/usage/ide-support.html
+It's recommended to either use [Metals](https://scalameta.org/metals/) with the
+editor of your choice or [the Scala Plugin for
+IntelliJ](https://blog.jetbrains.com/scala/).
 
 ## Using Scala 3 in an existing project
 
 ### build.sc
-Any version number that starts with `3.` is automatically recognized as Scala 3;
-you don't need to set up anything:
 
 ```scala
 def scalaVersion = "3.1.3"
 ```
 
-#### Nightly builds
-
-If the latest release of Scala 3 is missing a bugfix or feature you need, you may
-wish to use a nightly build. Look at the bottom of the list of
-[releases](https://repo1.maven.org/maven2/org/scala-lang/scala3-compiler_3/)
-to find the version number for the latest nightly build.
-
-## Getting your project to compile with Scala 3
-
-When porting an existing project, it's a good idea to start out with the Scala 2
-compatibility mode (note that this mode affects typechecking and thus may
-prevent some valid Scala 3 code from compiling) by adding to your `build.sc`:
-
-```scala
-def scalacOptions = T {
-  if (Dep.isDotty(scalaVersion()))
-    Seq("-language:Scala2")
-  else
-    Seq()
-}
-```
-
-Using the `Dep.isDotty` method ensures that this option will only be set when
-compiling with Scala 3.
-
-A tool to port code from Scala 2.x to Scala 3 is available; see
-https://scalacenter.github.io/scala-3-migration-guide/docs/tooling/scala-3-migrate-plugin.html
+### Getting your project to compile with Scala 3
 
-If your build contains dependencies that have only been published for Scala 2.x,
-you may be able to get them to work on Scala 3 by replacing:
+For help with porting an existing Scala 2 project to Scala 3, see the
+[Scala 3 migration guide](https://docs.scala-lang.org/scala3/guides/migration/compatibility-intro.html).
 
-```scala
-ivy"a::b:c"
-```
+## Need help?
 
-by:
-
-```scala
-ivy"a::b:c".withDottyCompat(scalaVersion())
-```
+https://www.scala-lang.org/community/ has links.

build.sc

@@ -1,7 +1,5 @@
 import mill._, scalalib._
 
-object root extends SbtModule {
-  def millSourcePath = ammonite.ops.pwd
+object examples extends ScalaModule {
   def scalaVersion = "3.1.3"
-  def publishVersion = "0.1.0"
 }

mill

@@ -3,27 +3,39 @@
 # This is a wrapper script, that automatically download mill from GitHub release pages
 # You can give the required mill version with MILL_VERSION env variable
 # If no version is given, it falls back to the value of DEFAULT_MILL_VERSION
-DEFAULT_MILL_VERSION=0.9.7
+DEFAULT_MILL_VERSION=0.10.5
 
 set -e
 
 if [ -z "$MILL_VERSION" ] ; then
   if [ -f ".mill-version" ] ; then
     MILL_VERSION="$(head -n 1 .mill-version 2> /dev/null)"
-  elif [ -f "mill" ] && [ "$BASH_SOURCE" != "mill" ] ; then
+  elif [ -f "mill" ] && [ "$0" != "mill" ] ; then
     MILL_VERSION=$(grep -F "DEFAULT_MILL_VERSION=" "mill" | head -n 1 | cut -d= -f2)
   else
     MILL_VERSION=$DEFAULT_MILL_VERSION
   fi
 fi
 
-MILL_DOWNLOAD_PATH="$HOME/.mill/download"
-MILL_EXEC_PATH="${MILL_DOWNLOAD_PATH}/$MILL_VERSION"
+if [ "x${XDG_CACHE_HOME}" != "x" ] ; then
+  MILL_DOWNLOAD_PATH="${XDG_CACHE_HOME}/mill/download"
+else
+  MILL_DOWNLOAD_PATH="${HOME}/.cache/mill/download"
+fi
+MILL_EXEC_PATH="${MILL_DOWNLOAD_PATH}/${MILL_VERSION}"
+
+version_remainder="$MILL_VERSION"
+MILL_MAJOR_VERSION="${version_remainder%%.*}"; version_remainder="${version_remainder#*.}"
+MILL_MINOR_VERSION="${version_remainder%%.*}"; version_remainder="${version_remainder#*.}"
 
-if [ ! -x "$MILL_EXEC_PATH" ] ; then
-  mkdir -p $MILL_DOWNLOAD_PATH
+if [ ! -s "$MILL_EXEC_PATH" ] ; then
+  mkdir -p "$MILL_DOWNLOAD_PATH"
+  if [ "$MILL_MAJOR_VERSION" -gt 0 ] || [ "$MILL_MINOR_VERSION" -ge 5 ] ; then
+    ASSEMBLY="-assembly"
+  fi
   DOWNLOAD_FILE=$MILL_EXEC_PATH-tmp-download
-  MILL_DOWNLOAD_URL="https://github.com/lihaoyi/mill/releases/download/${MILL_VERSION%%-*}/$MILL_VERSION-assembly"
+  MILL_VERSION_TAG=$(echo $MILL_VERSION | sed -E 's/([^-]+)(-M[0-9]+)?(-.*)?/\1\2/')
+  MILL_DOWNLOAD_URL="https://github.com/lihaoyi/mill/releases/download/${MILL_VERSION_TAG}/$MILL_VERSION${ASSEMBLY}"
   curl --fail -L -o "$DOWNLOAD_FILE" "$MILL_DOWNLOAD_URL"
   chmod +x "$DOWNLOAD_FILE"
   mv "$DOWNLOAD_FILE" "$MILL_EXEC_PATH"