Generate shell scripts.

Shell scripts are generated with `mkBin` sbt task that calls ScalaTool.
ScalaTool is defined in project/ and is a port of Ant task that lives
in scala.tools.ant.ScalaTool. While porting, we've simplified the code
significantly.

The `mkBin` task is defined in a new subproject: dist. This subproject
will become responsible for building the distribution in the future.

2 files changed, 45 insertions, 0 deletions

diff --git a/project/ScalaTool.scala b/project/ScalaTool.scala
new file mode 100644
index 0000000000..559b215c18
--- /dev/null
+++ b/project/ScalaTool.scala
@@ -0,0 +1,44 @@
+import sbt._
+import org.apache.commons.lang3.StringUtils.replaceEach
+
+/**
+ * A class that generates a shell or batch script to execute a Scala program.
+ *
+ * This is a simplified copy of Ant task (see scala.tools.ant.ScalaTool).
+ */
+case class ScalaTool(mainClass: String,
+                     classpath: List[String],
+                     properties: Map[String, String],
+                     javaOpts: String,
+                     toolFlags: String) {
+  //  For classpath, the platform specific
+  //  demarcation of any script variables (e.g. `${SCALA_HOME}` or
+  //  `%SCALA_HOME%`) can be specified in a platform independent way (e.g.
+  //  `@SCALA_HOME@`) and automatically translated for you.
+  def patchedToolScript(template: String, platform: String) = {
+    val varRegex = """@(\w+)@""" // the group should be able to capture each of the keys of the map below
+
+    val variables = Map(
+      ("@@"           -> "@"), // for backwards compatibility
+      ("@class@"      -> mainClass),
+      ("@properties@" -> (properties map { case (k, v) => s"""-D$k="$v""""} mkString " ")),
+      ("@javaflags@"  -> javaOpts),
+      ("@toolflags@"  -> toolFlags),
+      ("@classpath@"  -> (platform match {
+        case "unix"    => classpath.mkString(":").replace('\\', '/').replaceAll(varRegex, """\${$1}""")
+        case "windows" => classpath.mkString(";").replace('/', '\\').replaceAll(varRegex, "%$1%")
+      }))
+    )
+
+    val (from, to) = variables.unzip
+    replaceEach(template, from.toArray, to.toArray)
+  }
+
+  def writeScript(file: String, platform: String, rootDir: File, outDir: File): File = {
+    val templatePath = s"scala/tools/ant/templates/tool-$platform.tmpl"
+    val suffix       = platform match { case "windows" => ".bat" case _ => "" }
+    val scriptFile   = outDir / s"$file$suffix"
+    IO.write(scriptFile, patchedToolScript(IO.read(rootDir / templatePath), platform))
+    scriptFile
+  }
+}
diff --git a/project/plugins.sbt b/project/plugins.sbt
new file mode 100644
index 0000000000..dc266a8db1
--- /dev/null
+++ b/project/plugins.sbt
@@ -0,0 +1 @@
+libraryDependencies += "org.apache.commons" % "commons-lang3" % "3.3.2"
\ No newline at end of file