Introduces scala.tools.cmd providing command li...

Introduces scala.tools.cmd providing command line tool infrastructure.
For a quick look at what can be done, see

  scala.tools.cmd.Demo

For a more involved, potentially eye-straining look, see

  scala.tools.partest.PartestSpec

To experience it through the eyes of Joe Partest User, run

  test/partest

Review by community.

1 files changed, 98 insertions, 0 deletions

diff --git a/src/compiler/scala/tools/cmd/Reference.scala b/src/compiler/scala/tools/cmd/Reference.scala
new file mode 100644
index 0000000000..695868191b
--- /dev/null
+++ b/src/compiler/scala/tools/cmd/Reference.scala
@@ -0,0 +1,98 @@
+/* NSC -- new Scala compiler
+ * Copyright 2005-2010 LAMP/EPFL
+ * @author  Paul Phillips
+ */
+
+package scala.tools
+package cmd
+
+import collection.mutable.ListBuffer
+import nsc.Properties.envOrNone
+
+/** Mixes in the specification trait and uses the vals therein to
+ *  side-effect private accumulators.  From this emerges formatted help,
+ *  lists of unary and binary arguments, an apply which can creates
+ *  instances of the specification, and etc.
+ *
+ *  @see    Instance
+ */
+trait Reference extends Spec {
+  lazy val options = new Reference.Accumulators()
+  import options._
+
+  def helpMsg     = options.helpMsg
+  def propertyArgs: List[String] = Nil
+
+  def isUnaryOption(s: String)  = unary contains toOpt(s)
+  def isBinaryOption(s: String) = binary contains toOpt(s)
+  def isExpandOption(s: String) = expansionMap contains toOpt(s)
+  def isAnyOption(s: String)    = isUnaryOption(s) || isBinaryOption(s) || isExpandOption(s)
+
+  def expandArg(arg: String)      = expansionMap.getOrElse(fromOpt(arg), List(arg))
+
+  protected def help(str: => String)        = addHelp(() => str)
+
+  type ThisCommandLine <: SpecCommandLine
+  class SpecCommandLine(args: List[String]) extends CommandLine(Reference.this, args) { }
+  protected def creator(args: List[String]): ThisCommandLine
+  final def apply(args: String*): ThisCommandLine = creator(propertyArgs ++ args flatMap expandArg)
+
+  type OptionMagic = Opt.Reference
+  protected implicit def optionMagicAdditions(name: String) = new Opt.Reference(programInfo, options, name)
+}
+
+object Reference {
+  val MaxLine = 80
+
+  class Accumulators() {
+    private var _help     = new ListBuffer[() => String]
+    private var _unary   = List[String]()
+    private var _binary  = List[String]()
+    private var _expand  = Map[String, List[String]]()
+
+    def helpFormatStr     = "    %-" + longestArg + "s %s"
+    def defaultFormatStr  = (" " * (longestArg + 7)) + "%s"
+
+    def addUnary(s: String)   = _unary +:= s
+    def addBinary(s: String)  = _binary +:= s
+
+    def addExpand(opt: String, expanded: List[String]) =
+      _expand += (opt -> expanded)
+
+    def mapHelp(g: String => String) = {
+      val idx = _help.length - 1
+      val f = _help(idx)
+
+      _help(idx) = () => g(f())
+    }
+
+    def addHelp(f: () => String)      = _help += f
+    def addHelpAlias(f: () => String) = mapHelp { s =>
+      val str = "alias for '%s'" format f()
+      def noHelp = (helpFormatStr.format("", "")).length == s.length
+      val str2 = if (noHelp) str else " (" + str + ")"
+
+      s + str2
+    }
+    def addHelpDefault(f: () => String) = mapHelp { s =>
+      val str = "(default: %s)" format f()
+
+      if (s.length + str.length < MaxLine) s + " " + str
+      else defaultFormatStr.format(s, str)
+    }
+    def addHelpEnvDefault(name: String) = mapHelp { s =>
+      val line1     = "%s (default: %s)".format(s, name)
+      val envNow    = envOrNone(name) map ("'" + _ + "'") getOrElse "unset"
+      val line2     = defaultFormatStr.format("Currently " + envNow)
+
+      line1 + "\n" + line2
+    }
+
+    lazy val unary          = (_unary ++ _expand.keys).distinct
+    lazy val binary         = _binary.distinct
+    lazy val all            = unary ++ binary
+    lazy val expansionMap   = _expand
+    lazy val helpMsg        = _help map (f => f() + "\n") mkString
+    lazy val longestArg     = all map (_.length) max
+  }
+}