Added --import command-line option

docs/antora/modules/ROOT/pages/Contrib_Plugins.adoc

@@ -9,13 +9,22 @@ For details about including plugins in your `build.sc` read xref:Extending_Mill.
 --
 When using one of these contribution modules, it is important that the versions you load match your mill version.
 To facilitate this, Mill will automatically replace the `$MILL_VERSION` literal in your ivy imports with the correct value.
+You can also leave the version completely empty to default to the mill version (but don't forget to keep the trailing colon).
 
 For instance:
 
 [source,scala]
 ----
 import $ivy.`com.lihaoyi::mill-contrib-bloop:$MILL_VERSION`
 ----
+
+or
+
+[source,scala]
+----
+import $ivy.`com.lihaoyi::mill-contrib-bloop:`
+----
+
 --
 
 == Artifactory
@@ -26,7 +35,7 @@ This plugin allows publishing to Artifactory.
 
 [source,scala]
 ----
-import $ivy.`com.lihaoyi::mill-contrib-artifactory:$MILL_VERSION`
+import $ivy.`com.lihaoyi::mill-contrib-artifactory:`
 import mill.contrib.artifactory.ArtifactoryPublishModule
 
 object mymodule extends ArtifactoryPublishModule {
@@ -54,7 +63,7 @@ Make sure your module extends from `BintrayPublishModule`:
 
 [source,scala]
 ----
-import $ivy.`com.lihaoyi::mill-contrib-bintray:$MILL_VERSION`
+import $ivy.`com.lihaoyi::mill-contrib-bintray:`
 import mill.contrib.bintray.BintrayPublishModule
 
 object mymodule extends BintrayPublishModule {
@@ -73,7 +82,7 @@ the package used, you can do that like this:
 
 [source,scala]
 ----
-import $ivy.`com.lihaoyi::mill-contrib-bintray:$MILL_VERSION`
+import $ivy.`com.lihaoyi::mill-contrib-bintray:`
 import mill.contrib.bintray.BintrayPublishModule
 
 object mymodule extends BintrayPublishModule {
@@ -121,7 +130,7 @@ your scala code editable in https://scalameta.org/metals/[Metals]
 [source,scala]
 ----
 // build.sc (or any other .sc file it depends on, including predef)
-import $ivy.`com.lihaoyi::mill-contrib-bloop:$MILL_VERSION`
+import $ivy.`com.lihaoyi::mill-contrib-bloop:`
 ----
 
 Then in your terminal :
@@ -174,7 +183,7 @@ Quickstart:
 .`build.sc`
 [source,scala]
 ----
-import $ivy.`com.lihaoyi::mill-contrib-buildinfo:$MILL_VERSION`
+import $ivy.`com.lihaoyi::mill-contrib-buildinfo:`
 import mill.contrib.buildinfo.BuildInfo
 
 object project extends BuildInfo {
@@ -224,7 +233,7 @@ This plugin allows publishing to AWS Codeartifact.
 
 [source,scala]
 ----
-import $ivy.`com.lihaoyi::mill-contrib-codeartifact:$MILL_VERSION`
+import $ivy.`com.lihaoyi::mill-contrib-codeartifact:`
 import mill.contrib.codeartifact.CodeartifactPublishModule
 
 object mymodule extends CodeartifactPublishModule {
@@ -322,7 +331,7 @@ Configure flyway by overriding settings in your module. For example
 ----
 import mill._, scalalib._
 
-import $ivy.`com.lihaoyi::mill-contrib-flyway:$MILL_VERSION`
+import $ivy.`com.lihaoyi::mill-contrib-flyway:`
 import contrib.flyway.FlywayModule
 
 object foo extends ScalaModule with FlywayModule {
@@ -398,7 +407,7 @@ Twirl versions. You also need to define your own test object which extends the p
 [source,scala]
 ----
 import mill._
-import $ivy.`com.lihaoyi::mill-contrib-playlib:$MILL_VERSION`,  mill.playlib._
+import $ivy.`com.lihaoyi::mill-contrib-playlib:`,  mill.playlib._
 
 object core extends PlayModule {
     //config
@@ -587,7 +596,7 @@ by mixing in the `SingleModule` trait in your build:
 [source,scala]
 ----
 import mill._
-import $ivy.`com.lihaoyi::mill-contrib-playlib:$MILL_VERSION`,  mill.playlib._
+import $ivy.`com.lihaoyi::mill-contrib-playlib:`,  mill.playlib._
 
 object core extends PlayModule with SingleModule {
 	//config
@@ -632,7 +641,7 @@ define `playVersion` and `scalaVersion`.
 [source,scala]
 ----
 import mill._
-import $ivy.`com.lihaoyi::mill-contrib-playlib:$MILL_VERSION`,  mill.playlib._
+import $ivy.`com.lihaoyi::mill-contrib-playlib:`,  mill.playlib._
 
 object app extends ScalaModule with RouterModule {
   def playVersion= T{"2.7.0"}
@@ -715,7 +724,7 @@ Here is a simple example:
 .`build.sc`
 [source,scala]
 ----
-import $ivy.`com.lihaoyi::mill-contrib-proguard:$MILL_VERSION`
+import $ivy.`com.lihaoyi::mill-contrib-proguard:`
 import contrib.proguard._
 
 object foo extends ScalaModule with Proguard {
@@ -740,7 +749,7 @@ This creates a Scala module which compiles `.proto` files in the `protobuf` fold
 .`build.sc`
 [source,scala]
 ----
-import $ivy.`com.lihaoyi::mill-contrib-scalapblib:$MILL_VERSION`
+import $ivy.`com.lihaoyi::mill-contrib-scalapblib:`
 import contrib.scalapblib._
 
 object example extends ScalaPBModule {
@@ -779,7 +788,7 @@ If you'd like to configure the https://scalapb.github.io/docs/scalapbc#passing-g
 .`build.sc`
 [source,scala]
 ----
-import $ivy.`com.lihaoyi::mill-contrib-scalapblib:$MILL_VERSION`
+import $ivy.`com.lihaoyi::mill-contrib-scalapblib:`
 import contrib.scalapblib._
 
 object example extends ScalaPBModule {
@@ -819,7 +828,7 @@ module. Additionally, you must define a submodule that extends the
 .`build.sc`
 [source,scala]
 ----
-import $ivy.`com.lihaoyi::mill-contrib-scoverage:$MILL_VERSION`
+import $ivy.`com.lihaoyi::mill-contrib-scoverage:`
 import mill.contrib.scoverage.ScoverageModule
 
 object foo extends ScoverageModule  {
@@ -924,7 +933,7 @@ Also note that twirl templates get compiled into scala code, so you also need to
 ----
 import mill.scalalib._
 
-import $ivy.`com.lihaoyi::mill-contrib-twirllib:$MILL_VERSION`,  mill.twirllib._
+import $ivy.`com.lihaoyi::mill-contrib-twirllib:`,  mill.twirllib._
 
 object app extends ScalaModule with TwirlModule {
 // ...
@@ -961,7 +970,7 @@ directory. This directory must be added to the generated sources of the module t
 ----
 import mill.scalalib._
 
-import $ivy.`com.lihaoyi::mill-contrib-twirllib:$MILL_VERSION`,  mill.twirllib._
+import $ivy.`com.lihaoyi::mill-contrib-twirllib:`,  mill.twirllib._
 
 object app extends ScalaModule with TwirlModule {
   def twirlVersion = "1.3.15"
@@ -998,7 +1007,7 @@ To add additional imports to all of the twirl templates, override `twirlImports`
 ----
 import mill.scalalib._
 
-import $ivy.`com.lihaoyi::mill-contrib-twirllib:$MILL_VERSION`,  mill.twirllib._
+import $ivy.`com.lihaoyi::mill-contrib-twirllib:`,  mill.twirllib._
 
 object app extends ScalaModule with TwirlModule {
   def twirlVersion = "1.3.15"
@@ -1040,7 +1049,7 @@ To add additional formats, override `twirlFormats` in your build:
 ----
 import mill.scalalib._
 
-import $ivy.`com.lihaoyi::mill-contrib-twirllib:$MILL_VERSION`,  mill.twirllib._
+import $ivy.`com.lihaoyi::mill-contrib-twirllib:`,  mill.twirllib._
 
 object app extends ScalaModule with TwirlModule {
   def twirlVersion = "1.3.15"
@@ -1078,7 +1087,7 @@ Add a `VersionFileModule` to the `build.sc` file:
 
 [source,scala]
 ----
-import $ivy.`com.lihaoyi::mill-contrib-versionfile:$MILL_VERSION`
+import $ivy.`com.lihaoyi::mill-contrib-versionfile:`
 import mill.contrib.versionfile.VersionFileModule
 
 object versionFile extends VersionFileModule
@@ -1115,7 +1124,7 @@ If you want to use the version file for publishing, you can do it like this:
 
 [source,scala]
 ----
-import $ivy.`com.lihaoyi::mill-contrib-versionfile:$MILL_VERSION`
+import $ivy.`com.lihaoyi::mill-contrib-versionfile:`
 import mill.contrib.versionfile.VersionFileModule
 
 object versionFile extends VersionFileModule
@@ -1135,7 +1144,7 @@ at the root of the project, you can override `millSourcePath`:
 
 [source,scala]
 ----
-import $ivy.`com.lihaoyi::mill-contrib-versionfile:$MILL_VERSION`
+import $ivy.`com.lihaoyi::mill-contrib-versionfile:`
 import mill.contrib.versionfile.VersionFileModule
 
 object versionFile extends VersionFileModule {

docs/antora/modules/ROOT/pages/Extending_Mill.adoc

@@ -201,6 +201,15 @@ This is typical required for Mill contrib modules, which are developed in the Mi
 ----
 import $ivy:`com.lihaoyi:mill-contrib-bloop:$MILL_VERSION`
 ----
+
+There is the even more convenient option to leave the version completely empty.
+Mill will substitute it with its current version.
+But don't forget to provide the trailing colon!
+
+.Example: Use `mill-contrib-bloop` plugin matching the current Mill version
+----
+import $ivy:`com.lihaoyi:mill-contrib-bloop:`
+----
 --
 
 `$MILL_BIN_PLATFORM` ::

main/src/mill/MillConfig.scala

@@ -0,0 +1,82 @@
+package mill
+
+import mainargs.{Flag, Leftover, arg}
+
+case class MillConfig(
+    ammoniteCore: ammonite.main.Config.Core,
+    @arg(
+      short = 'h',
+      doc =
+        "The home directory of the REPL; where it looks for config and caches"
+    )
+    home: os.Path = mill.api.Ctx.defaultHome,
+    @arg(
+      doc =
+        """Run Mill in interactive mode and start a build REPL. In this mode, no
+    mill server will be used. Must be the first argument."""
+    )
+    repl: Flag,
+    @arg(
+      name = "no-server",
+      doc =
+        """Run Mill in interactive mode, suitable for opening REPLs and taking user
+      input. In this mode, no mill server will be used. Must be the first argument."""
+    )
+    noServer: Flag,
+    @arg(
+      short = 'i',
+      doc =
+        """Run Mill in interactive mode, suitable for opening REPLs and taking user
+      input. In this mode, no mill server will be used. Must be the first argument."""
+    )
+    interactive: Flag,
+    @arg(name = "version", short = 'v', doc = "Show mill version and exit.")
+    showVersion: Flag,
+    @arg(
+      name = "bell",
+      short = 'b',
+      doc =
+        "Ring the bell once if the run completes successfully, twice if it fails."
+    )
+    ringBell: Flag,
+    @arg(
+      name = "disable-ticker",
+      doc =
+        "Disable ticker log (e.g. short-lived prints of stages and progress bars)"
+    )
+    disableTicker: Flag,
+    @arg(name = "debug", short = 'd', doc = "Show debug output on STDOUT")
+    debugLog: Flag,
+    @arg(
+      name = "keep-going",
+      short = 'k',
+      doc = "Continue build, even after build failures"
+    )
+    keepGoing: Flag,
+    @arg(
+      name = "define",
+      short = 'D',
+      doc = "Define (or overwrite) a system property"
+    )
+    extraSystemProperties: Map[String, String],
+    @arg(
+      name = "jobs",
+      short = 'j',
+      doc =
+        """Allow processing N targets in parallel. Use 1 to disable parallel and 0 to
+      use as much threads as available processors."""
+    )
+    threadCountRaw: Option[Int],
+    @arg(
+      name = "import",
+      doc = """Additional ivy dependencies to load into mill, e.g. plugins."""
+    )
+    imports: Seq[String],
+    @arg(
+      name = "rest",
+      doc =
+        """The name of the targets you want to build, followed by any parameters
+      you wish to pass to those targets."""
+    )
+    leftoverArgs: Leftover[String]
+)

main/src/mill/MillConfigParser.scala

@@ -0,0 +1,30 @@
+package mill
+
+import mainargs.ParserForClass
+import ammonite.repl.tools.Util.PathRead
+
+object MillConfigParser {
+
+  val customName = s"Mill Build Tool, version ${BuildInfo.millVersion}"
+  val customDoc = "usage: mill [options] [[target [target-options]] [+ [target ...]]]"
+
+  private[this] lazy val parser: ParserForClass[MillConfig] = mainargs.ParserForClass[MillConfig]
+
+  lazy val usageText = parser.helpText(customName = customName, customDoc = customDoc)
+
+  def parse(args: Array[String]): Either[String, MillConfig] = {
+    parser.constructEither(
+      args,
+      allowRepeats = true,
+      autoPrintHelpAndExit = None,
+      customName = customName,
+      customDoc = customDoc
+    )
+      .map { config =>
+        config.copy(
+          ammoniteCore = config.ammoniteCore.copy(home = config.home)
+        )
+      }
+  }
+
+}