Move all overridable bits into Config class

Central config class replaces mixture of parameters and fields.
The fields were in part in the wrong class, where they could not
easily be overridden.

3 files changed, 60 insertions, 55 deletions

diff --git a/src/dotty/tools/dotc/repl/InterpreterLoop.scala b/src/dotty/tools/dotc/repl/InterpreterLoop.scala
index eedec3c82..4ac9602e7 100644
--- a/src/dotty/tools/dotc/repl/InterpreterLoop.scala
+++ b/src/dotty/tools/dotc/repl/InterpreterLoop.scala
@@ -21,10 +21,10 @@ import scala.concurrent.ExecutionContext.Implicits.global
  *  @author  Lex Spoon
  *  @author Martin Odersky
  */
-class InterpreterLoop(
-    compiler: Compiler,
-    private var in: InteractiveReader,
-    out: PrintWriter)(implicit ctx: Context) {
+class InterpreterLoop(compiler: Compiler, config: REPL.Config)(implicit ctx: Context) {
+  import config._
+
+  private var in = input
 
   val interpreter = compiler.asInstanceOf[Interpreter]
 
@@ -52,24 +52,20 @@ class InterpreterLoop(
   /** print a friendly help message */
   def printHelp(): Unit = {
     printWelcome()
-    out.println("Type :load followed by a filename to load a Scala file.")
-    out.println("Type :replay to reset execution and replay all previous commands.")
-    out.println("Type :quit to exit the interpreter.")
+    output.println("Type :load followed by a filename to load a Scala file.")
+    output.println("Type :replay to reset execution and replay all previous commands.")
+    output.println("Type :quit to exit the interpreter.")
   }
 
   /** Print a welcome message */
   def printWelcome(): Unit = {
-    out.println(s"Welcome to Scala$version " + " (" +
+    output.println(s"Welcome to Scala$version " + " (" +
                 System.getProperty("java.vm.name") + ", Java " + System.getProperty("java.version") + ")." )
-    out.println("Type in expressions to have them evaluated.")
-    out.println("Type :help for more information.")
-    out.flush()
+    output.println("Type in expressions to have them evaluated.")
+    output.println("Type :help for more information.")
+    output.flush()
   }
 
-  /** Prompt to print when awaiting input */
-  val prompt             = "scala> "
-  val continuationPrompt = "     | "
-
   val version = ".next (pre-alpha)"
 
   /** The first interpreted command always takes a couple of seconds
@@ -92,7 +88,7 @@ class InterpreterLoop(
       val (keepGoing, finalLineOpt) = command(line)
       if (keepGoing) {
         finalLineOpt.foreach(addReplay)
-        out.flush()
+        output.flush()
         repl()
       }
     }
@@ -103,16 +99,16 @@ class InterpreterLoop(
       new FileReader(filename)
     } catch {
       case _: IOException =>
-        out.println("Error opening file: " + filename)
+        output.println("Error opening file: " + filename)
         return
     }
     val oldIn = in
     val oldReplay = replayCommandsRev
     try {
       val inFile = new BufferedReader(fileIn)
-      in = new SimpleReader(inFile, out, false)
-      out.println("Loading " + filename + "...")
-      out.flush
+      in = new SimpleReader(inFile, output, false)
+      output.println("Loading " + filename + "...")
+      output.flush
       repl()
     } finally {
       in = oldIn
@@ -124,10 +120,10 @@ class InterpreterLoop(
   /** create a new interpreter and replay all commands so far */
   def replay(): Unit = {
     for (cmd <- replayCommands) {
-      out.println("Replaying: " + cmd)
-      out.flush()  // because maybe cmd will have its own output
+      output.println("Replaying: " + cmd)
+      output.flush()  // because maybe cmd will have its own output
       command(cmd)
-      out.println
+      output.println
     }
   }
 
@@ -138,12 +134,12 @@ class InterpreterLoop(
     def withFile(command: String)(action: String => Unit): Unit = {
       val spaceIdx = command.indexOf(' ')
       if (spaceIdx <= 0) {
-        out.println("That command requires a filename to be specified.")
+        output.println("That command requires a filename to be specified.")
         return
       }
       val filename = command.substring(spaceIdx).trim
       if (!new File(filename).exists) {
-        out.println("That file does not exist")
+        output.println("That file does not exist")
         return
       }
       action(filename)
@@ -169,7 +165,7 @@ class InterpreterLoop(
     else if (line matches replayRegexp)
       replay()
     else if (line startsWith ":")
-      out.println("Unknown command.  Type :help for help.")
+      output.println("Unknown command.  Type :help for help.")
     else
       shouldReplay = interpretStartingWith(line)
 
@@ -188,7 +184,7 @@ class InterpreterLoop(
       case Interpreter.Error => None
       case Interpreter.Incomplete =>
         if (in.interactive && code.endsWith("\n\n")) {
-          out.println("You typed two blank lines.  Starting a new command.")
+          output.println("You typed two blank lines.  Starting a new command.")
           None
         } else {
           val nextLine = in.readLine(continuationPrompt)
@@ -207,7 +203,7 @@ class InterpreterLoop(
           val cmd = ":load " + filename
           command(cmd)
           replayCommandsRev = cmd :: replayCommandsRev
-          out.println()
+          output.println()
         }
       case _ =>
     }
diff --git a/src/dotty/tools/dotc/repl/REPL.scala b/src/dotty/tools/dotc/repl/REPL.scala
index 2d6a3c742..e5ff2d3af 100644
--- a/src/dotty/tools/dotc/repl/REPL.scala
+++ b/src/dotty/tools/dotc/repl/REPL.scala
@@ -23,27 +23,37 @@ import java.io.{BufferedReader, File, FileReader, PrintWriter}
  */
 class REPL extends Driver {
 
-  /** The default input reader */
-  def input(implicit ctx: Context): InteractiveReader = {
-    val emacsShell = System.getProperty("env.emacs", "") != ""
-    //println("emacsShell="+emacsShell) //debug
-    if (ctx.settings.Xnojline.value || emacsShell) new SimpleReader()
-    else InteractiveReader.createDefault()
-  }
-
-  /** The defult output writer */
-  def output: PrintWriter = new NewLinePrintWriter(new ConsoleWriter, true)
+  lazy val config = new REPL.Config
 
   override def newCompiler(implicit ctx: Context): Compiler =
-    new repl.CompilingInterpreter(output, ctx)
+    new repl.CompilingInterpreter(config.output, ctx)
 
   override def sourcesRequired = false
 
   override def doCompile(compiler: Compiler, fileNames: List[String])(implicit ctx: Context): Reporter = {
     if (fileNames.isEmpty)
-      new InterpreterLoop(compiler, input, output).run()
+      new InterpreterLoop(compiler, config).run()
     else
       ctx.error(s"don't now what to do with $fileNames%, %")
     ctx.reporter
   }
 }
+
+object REPL {
+  class Config {
+    val prompt             = "scala> "
+    val continuationPrompt = "     | "
+    val version            = ".next (pre-alpha)"
+
+    /** The default input reader */
+    def input(implicit ctx: Context): InteractiveReader = {
+      val emacsShell = System.getProperty("env.emacs", "") != ""
+      //println("emacsShell="+emacsShell) //debug
+      if (ctx.settings.Xnojline.value || emacsShell) new SimpleReader()
+      else InteractiveReader.createDefault()
+    }
+
+    /** The default output writer */
+    def output: PrintWriter = new NewLinePrintWriter(new ConsoleWriter, true)
+  }
+}
diff --git a/test/test/TestREPL.scala b/test/test/TestREPL.scala
index a9978cdde..30dad2b64 100644
--- a/test/test/TestREPL.scala
+++ b/test/test/TestREPL.scala
@@ -5,32 +5,31 @@ import dotty.tools.dotc.core.Contexts.Context
 import collection.mutable
 import java.io.StringWriter
 
-
 class TestREPL(script: String) extends REPL {
 
-  private val prompt             = "scala> "
-  private val continuationPrompt = "     | "
-
   private val out = new StringWriter()
-  override val output = new NewLinePrintWriter(out)
 
-  override def input(implicit ctx: Context) = new InteractiveReader {
-    val lines = script.lines
-    def readLine(prompt: String): String = {
-      val line = lines.next
-      if (line.startsWith(prompt) || line.startsWith(continuationPrompt)) {
-        output.println(line)
-        line.drop(prompt.length)
+  override lazy val config = new REPL.Config {
+    override val output = new NewLinePrintWriter(out)
+
+    override def input(implicit ctx: Context) = new InteractiveReader {
+      val lines = script.lines
+      def readLine(prompt: String): String = {
+        val line = lines.next
+        if (line.startsWith(prompt) || line.startsWith(continuationPrompt)) {
+          output.println(line)
+          line.drop(prompt.length)
+        }
+        else readLine(prompt)
       }
-      else readLine(prompt)
+      val interactive = false
     }
-    val interactive = false
   }
 
   def check() = {
     out.close()
     val printed = out.toString
-    val transcript = printed.drop(printed.indexOf(prompt))
+    val transcript = printed.drop(printed.indexOf(config.prompt))
     if (transcript.toString != script) {
       println("input differs from transcript:")
       println(transcript)