- start prime the interpreter sooner, so that t...

- start prime the interpreter sooner, so that the first entered command
will respond sooner

- count to two, for the usual value of two

2 files changed, 32 insertions, 3 deletions

diff --git a/src/compiler/scala/tools/nsc/Interpreter.scala b/src/compiler/scala/tools/nsc/Interpreter.scala
index e16839956c..43852df28b 100644
--- a/src/compiler/scala/tools/nsc/Interpreter.scala
+++ b/src/compiler/scala/tools/nsc/Interpreter.scala
@@ -82,6 +82,17 @@ class Interpreter(val settings: Settings, reporter: Reporter, out: PrintWriter)
     * submitted command unless an exception is thrown.  */
   def beQuiet = { printResults = false }
 
+  /** Temporarily be quiet */
+  def beQuietDuring[T](operation: => T): T = {
+    val wasPrinting = printResults
+    try {
+      printResults = false
+      operation
+    } finally {
+      printResults = wasPrinting
+    }
+  }
+
   /** directory to save .class files to */
   val classfilePath = File.createTempFile("scalaint", "")
   classfilePath.delete  // the file is created as a file; make it a directory
@@ -167,7 +178,6 @@ class Interpreter(val settings: Settings, reporter: Reporter, out: PrintWriter)
   private def parse(line: String): Option[List[Tree]] = {
     var justNeedsMore = false
     reporter.withIncompleteHandler((pos,msg) => {justNeedsMore = true}) {
-//reporter.incompleteInputError = (pos,msg) => {justNeedsMore = true}
       // simple parse: just parse it, nothing else
       def simpleParse(code: String): List[Tree] = {
         val unit =
@@ -329,6 +339,19 @@ class Interpreter(val settings: Settings, reporter: Reporter, out: PrintWriter)
   }
 
 
+  /** Make a dry run in order to fill caches.  This is useful
+    * for interactive interpreters so that the interpreter responds
+    * quickly to the first user-supplied query.
+    */
+  def prime: Unit = beQuietDuring {
+    interpret("0")
+
+    // the next two lines are cosmetic; they cause
+    // the line number to go back to what it was
+    nextLineNo = nextLineNo - 1
+    prevRequests.remove(prevRequests.length - 1)
+  }
+
   /** <p>
    *    This instance is no longer needed, so release any resources
    *    it is using.
diff --git a/src/compiler/scala/tools/nsc/InterpreterLoop.scala b/src/compiler/scala/tools/nsc/InterpreterLoop.scala
index 220cdfc8cf..6cc2fd27f3 100644
--- a/src/compiler/scala/tools/nsc/InterpreterLoop.scala
+++ b/src/compiler/scala/tools/nsc/InterpreterLoop.scala
@@ -94,11 +94,16 @@ class InterpreterLoop(in0: BufferedReader, out: PrintWriter) {
    *  <code>command()</code> for each line of input, and stops when
    *  <code>command()</code> returns false.
    */
-  def repl(): Unit =
+  def repl(): Unit = {
+    var firstTime = true
     while(true) {
       if(interactive) {
         out.print("\nscala> ")
         out.flush
+        if(firstTime) {
+          interpreter.prime
+          firstTime = false
+        }
       }
       var line = in.readLine()
       if (line eq null)
@@ -114,6 +119,7 @@ class InterpreterLoop(in0: BufferedReader, out: PrintWriter) {
         case None => ()
       }
     }
+  }
 
   /** interpret all lines from a specified file */
   def interpretAllFrom(filename: String): Unit = {
@@ -214,7 +220,7 @@ class InterpreterLoop(in0: BufferedReader, out: PrintWriter) {
       case IR.Success => Some(code)
       case IR.Error => None
       case IR.Incomplete => {
-        if(interactive && code.endsWith("\n\n\n")) {
+        if(interactive && code.endsWith("\n\n")) {
           out.println("Two blank lines seen.  Aborting this expression.")
           None
         } else {