Add initialCommands and cleanupCommands to REPL

Author: felixmulder

src/dotty/tools/dotc/repl/InterpreterLoop.scala

@@ -68,17 +68,6 @@ class InterpreterLoop(compiler: Compiler, config: REPL.Config)(implicit ctx: Con
 
   val version = ".next (pre-alpha)"
 
-  /** The first interpreted command always takes a couple of seconds
-   *  due to classloading. To bridge the gap, we warm up the interpreter
-   *  by letting it interpret a dummy line while waiting for the first
-   *  line of input to be entered.
-   */
-  def firstLine(): String = {
-    interpreter.beQuietDuring(
-      interpreter.interpret("val theAnswerToLifeInTheUniverseAndEverything = 21 * 2"))
-    in.readLine(prompt)
-  }
-
   /** The main read-eval-print loop for the interpreter.  It calls
    *  `command()` for each line of input.
    */
@@ -177,6 +166,10 @@ class InterpreterLoop(compiler: Compiler, config: REPL.Config)(implicit ctx: Con
     (true, shouldReplay)
   }
 
+  def silentlyRun(cmds: List[String]): Unit = cmds.foreach { cmd =>
+    interpreter.beQuietDuring(interpreter.interpret(cmd))
+  }
+
   /** Interpret expressions starting with the first line.
     * Read lines until a complete compilation unit is available
     * or until a syntax error has been seen.  If a full unit is
@@ -207,7 +200,9 @@ class InterpreterLoop(compiler: Compiler, config: REPL.Config)(implicit ctx: Con
     try {
       if (!ctx.reporter.hasErrors) { // if there are already errors, no sense to continue
         printWelcome()
-        repl(firstLine())
+        silentlyRun(config.initialCommands)
+        repl(in.readLine(prompt))
+        silentlyRun(config.cleanupCommands)
       }
     } finally {
       closeInterpreter()

src/dotty/tools/dotc/repl/REPL.scala

@@ -52,6 +52,19 @@ object REPL {
 
     def context(ctx: Context): Context = ctx
 
+    /** The first interpreted commands always take a couple of seconds due to
+     *  classloading. To bridge the gap, we warm up the interpreter by letting it
+     *  interpret at least a dummy line while waiting for the first line of input
+     *  to be entered.
+     */
+    val initialCommands: List[String] =
+      "val theAnswerToLifeInTheUniverseAndEverything = 21 * 2" :: Nil
+
+    /** We also allow the use of setting cleanup commands in the same manner.
+     *  This is mainly due to supporting the SBT options to specify these commands
+     */
+    val cleanupCommands: List[String] = Nil
+
     /** The default input reader */
     def input(in: Interpreter)(implicit ctx: Context): InteractiveReader = {
       val emacsShell = System.getProperty("env.emacs", "") != ""