1 files changed, 60 insertions, 15 deletions
diff --git a/src/compiler/scala/tools/nsc/InterpreterLoop.scala b/src/compiler/scala/tools/nsc/InterpreterLoop.scala
index 76f09f07f7..2b926d8e80 100644
--- a/src/compiler/scala/tools/nsc/InterpreterLoop.scala
+++ b/src/compiler/scala/tools/nsc/InterpreterLoop.scala
@@ -10,6 +10,7 @@ import java.io.{ BufferedReader, File, FileReader, PrintWriter }
 import java.io.IOException
 
 import scala.tools.nsc.{ InterpreterResults => IR }
+import scala.collection.JavaConversions.asBuffer
 import interpreter._
 import io.{ Process }
 
@@ -22,30 +23,34 @@ object InterpreterControl {
 
   // a single interpreter command
   sealed abstract class Command extends Function1[List[String], Result] {
-    val name: String
-    val help: String
+    def name: String
+    def help: String
     def error(msg: String) = {
       println(":" + name + " " + msg + ".")
       Result(true, None)
     }
-    def getHelp(): String = ":" + name + " " + help + "."
+    def usage(): String
   }
 
   case class NoArgs(name: String, help: String, f: () => Result) extends Command {
+    def usage(): String = ":" + name
     def apply(args: List[String]) = if (args.isEmpty) f() else error("accepts no arguments")
   }
 
   case class LineArg(name: String, help: String, f: (String) => Result) extends Command {
+    def usage(): String = ":" + name + " <line>"
     def apply(args: List[String]) = f(args mkString " ")
   }
 
   case class OneArg(name: String, help: String, f: (String) => Result) extends Command {
+    def usage(): String = ":" + name + " <arg>"
     def apply(args: List[String]) =
       if (args.size == 1) f(args.head)
       else error("requires exactly one argument")
   }
 
   case class VarArgs(name: String, help: String, f: (List[String]) => Result) extends Command {
+    def usage(): String = ":" + name + " [arg]"
     def apply(args: List[String]) = f(args)
   }
 
@@ -54,8 +59,6 @@ object InterpreterControl {
 }
 import InterpreterControl._
 
-// import scala.concurrent.ops.defaultRunner
-
 /** The
  *  <a href="http://scala-lang.org/" target="_top">Scala</a>
  *  interactive shell.  It provides a read-eval-print loop around
@@ -76,6 +79,12 @@ class InterpreterLoop(in0: Option[BufferedReader], out: PrintWriter) {
 
   /** The input stream from which commands come, set by main() */
   var in: InteractiveReader = _
+  def history = in match {
+    case x: JLineReader => Some(x.history)
+    case _              => None
+  }
+  def historyList: Seq[String] =
+    history map (x => asBuffer(x.getHistoryList): Seq[String]) getOrElse Nil
 
   /** The context class loader at the time this object was created */
   protected val originalClassLoader = Thread.currentThread.getContextClassLoader
@@ -126,8 +135,11 @@ class InterpreterLoop(in0: Option[BufferedReader], out: PrintWriter) {
 
   /** print a friendly help message */
   def printHelp() = {
-    out println "All commands can be abbreviated - for example :h or :he instead of :help.\n"
-    commands foreach { c => out println c.getHelp }
+    out println "All commands can be abbreviated - for example :he instead of :help.\n"
+    val cmds = commands map (x => (x.usage, x.help))
+    val width: Int = cmds map { case (x, _) => x.length } max
+    val formatStr = "%-" + width + "s %s"
+    cmds foreach { case (usage, help) => out println formatStr.format(usage, help) }
   }
 
   /** Print a welcome message */
@@ -143,6 +155,36 @@ class InterpreterLoop(in0: Option[BufferedReader], out: PrintWriter) {
     out.flush
   }
 
+  /** Show the history */
+  def printHistory(xs: List[String]) {
+    val defaultLines = 20
+
+    if (history.isEmpty)
+      return println("No history available.")
+
+    val current = history.get.getCurrentIndex
+    val count = try xs.head.toInt catch { case _: Exception => defaultLines }
+    val lines = historyList takeRight count
+    val offset = current - lines.size + 1
+
+    for ((line, index) <- lines.zipWithIndex)
+      println("%d %s".format(index + offset, line))
+  }
+
+  /** Search the history */
+  def searchHistory(_cmdline: String) {
+    val cmdline = _cmdline.toLowerCase
+
+    if (history.isEmpty)
+      return println("No history available.")
+
+    val current = history.get.getCurrentIndex
+    val offset = current - historyList.size + 1
+
+    for ((line, index) <- historyList.zipWithIndex ; if line.toLowerCase contains cmdline)
+      println("%d %s".format(index + offset, line))
+  }
+
   /** Prompt to print when awaiting input */
   val prompt = Properties.shellPromptString
 
@@ -160,13 +202,15 @@ class InterpreterLoop(in0: Option[BufferedReader], out: PrintWriter) {
   val standardCommands: List[Command] = {
     import CommandImplicits._
     List(
-       NoArgs("help", "prints this help message", printHelp),
+       NoArgs("help", "print this help message", printHelp),
+       VarArgs("history", "show the history (optional arg: lines to show)", printHistory),
+       LineArg("h?", "search the history", searchHistory),
        OneArg("jar", "add a jar to the classpath", addJar),
-       OneArg("load", "followed by a filename loads a Scala file", load),
+       OneArg("load", "load and interpret a Scala file", load),
        NoArgs("power", "enable power user mode", power),
-       NoArgs("quit", "exits the interpreter", () => Result(false, None)),
-       NoArgs("replay", "resets execution and replays all previous commands", replay),
-       LineArg("sh", "forks a shell and runs a command", runShellCmd),
+       NoArgs("quit", "exit the interpreter", () => Result(false, None)),
+       NoArgs("replay", "reset execution and replay all previous commands", replay),
+       LineArg("sh", "fork a shell and run a command", runShellCmd),
        NoArgs("silent", "disable/enable automatic printing of results", verbosity)
     )
   }
@@ -296,9 +340,10 @@ class InterpreterLoop(in0: Option[BufferedReader], out: PrintWriter) {
     replay()
   }
 
-  def power() = {
+  def power() {
     powerUserOn = true
     interpreter.powerUser()
+    interpreter.quietBind("history", "scala.collection.immutable.List[String]", historyList.toList)
   }
 
   def verbosity() = {
@@ -381,7 +426,7 @@ class InterpreterLoop(in0: Option[BufferedReader], out: PrintWriter) {
         // the interpeter is passed as an argument to expose tab completion info
         if (settings.Xnojline.value || emacsShell) new SimpleReader
         else if (settings.noCompletion.value) InteractiveReader.createDefault()
-        else InteractiveReader.createDefault(interpreter)
+        else InteractiveReader.createDefault(interpreter, this)
     }
 
     loadFiles(settings)
@@ -399,7 +444,7 @@ class InterpreterLoop(in0: Option[BufferedReader], out: PrintWriter) {
   // injects one value into the repl; returns pair of name and class
   def injectOne(name: String, obj: Any): Tuple2[String, String] = {
     val className = obj.asInstanceOf[AnyRef].getClass.getName
-    interpreter.bind(name, className, obj)
+    interpreter.quietBind(name, className, obj)
     (name, className)
   }