Change into educational example

build.sbt

@@ -1,55 +1,39 @@
 // See README.md for license details.
 
-def scalacOptionsVersion(scalaVersion: String): Seq[String] = {
-  Seq() ++ {
-    // If we're building with Scala > 2.11, enable the compile option
-    //  switch to support our anonymous Bundle definitions:
-    //  https://github.com/scala/bug/issues/10047
-    CrossVersion.partialVersion(scalaVersion) match {
-      case Some((2, scalaMajor: Long)) if scalaMajor < 12 => Seq()
-      case _ => Seq("-Xsource:2.11")
-    }
-  }
-}
-
-def javacOptionsVersion(scalaVersion: String): Seq[String] = {
-  Seq() ++ {
-    // Scala 2.12 requires Java 8. We continue to generate
-    //  Java 7 compatible code for Scala 2.11
-    //  for compatibility with old clients.
-    CrossVersion.partialVersion(scalaVersion) match {
-      case Some((2, scalaMajor: Long)) if scalaMajor < 12 =>
-        Seq("-source", "1.7", "-target", "1.7")
-      case _ =>
-        Seq("-source", "1.8", "-target", "1.8")
-    }
-  }
-}
-
-name := "chisel-module-template"
-
-version := "3.3-SNAPSHOT"
-
-scalaVersion := "2.12.10"
-
-crossScalaVersions := Seq("2.12.10", "2.11.12")
-
-resolvers ++= Seq(
-  Resolver.sonatypeRepo("snapshots"),
-  Resolver.sonatypeRepo("releases")
-)
-
-addCompilerPlugin("org.scalamacros" % "paradise" % "2.1.0" cross CrossVersion.full)
-
-// Provide a managed dependency on X if -DXVersion="" is supplied on the command line.
-val defaultVersions = Seq(
-  "chisel-iotesters" -> "1.5-SNAPSHOT",
-  "chiseltest" -> "0.3-SNAPSHOT"
+// Common properties shared for a whole build
+ThisBuild / scalaVersion := "2.12.12"
+// These settings are mainly for publishing, they should be customized by the user
+ThisBuild / organization := "edu.berkeley.cs"
+ThisBuild / version      := "3.3-SNAPSHOT" // SNAPSHOT is used to indicate development
+
+// A project is a compilation unit
+// Many projects are fine with just one (like this example), but complex builds may have multiple
+// The properties scoped in "ThisBuild" above are shared between all projects
+lazy val chiselTemplate = (project in file("."))
+  .settings(
+    name := "chisel-module-template",
+    libraryDependencies ++= Seq(
+      // Fundamentally, Chisel is just a Scala library, so we depend on it as a library
+      // Chisel 3 is versioning is of the style "3.<major>.<minor>"
+      // Chisel maintains binary compatibility between minor versions
+      // We use '+' to pull newest minor version
+      "edu.berkeley.cs" %% "chisel3" % "3.3.+",
+      // By default, dependencies are in the "main" scope, projects also have a "test" scope
+      // main code lives in "src/main/", test is found in "src/test/"
+      // The following depenencies will only be available in "src/test/"
+      "edu.berkeley.cs" %% "chisel-iotesters" % "1.4.+" % "test",
+      // Leading with a 0 indicates less stability so it's generally good to pin a specific version,
+      // It's also reasonable to pin specific versions for the above dependencies as well
+      "edu.berkeley.cs" %% "chiseltest" % "0.2.2" % "test"
+    ),
+    scalacOptions ++= Seq(
+      // Required options for Chisel code
+      "-Xsource:2.11",
+      // Recommended options
+      "-language:reflectiveCalls",
+      "-deprecation",
+      "-feature",
+      "-Xcheckinit"
+    )
   )
 
-libraryDependencies ++= defaultVersions.map { case (dep, ver) =>
-  "edu.berkeley.cs" %% dep % sys.props.getOrElse(dep + "Version", ver) }
-
-scalacOptions ++= scalacOptionsVersion(scalaVersion.value)
-
-javacOptions ++= javacOptionsVersion(scalaVersion.value)