1 files changed, 112 insertions, 54 deletions
diff --git a/src/compiler/scala/tools/nsc/MainInterpreter.scala b/src/compiler/scala/tools/nsc/MainInterpreter.scala
index b1ea38e065..4727cd8cc9 100644
--- a/src/compiler/scala/tools/nsc/MainInterpreter.scala
+++ b/src/compiler/scala/tools/nsc/MainInterpreter.scala
@@ -3,72 +3,130 @@
  * @author emir
  */
 // $Id$
-package scala.tools.nsc;
+package scala.tools.nsc
 
-import java.io._;
-import scala.tools.nsc.util.{Position};
-import scala.tools.nsc.reporters.{Reporter, ConsoleReporter};
+import java.io._
+import scala.tools.nsc.util.{Position}
+import scala.tools.nsc.reporters.{Reporter, ConsoleReporter}
 
 /** The main class for the new scala interpreter.
  */
-object MainInterpreter extends Object with EvalLoop {
-  // lots of stuff duplicated from Main
-  val PRODUCT: String =
-    System.getProperty("scala.product", "scalaint");
-  val VERSION: String =
-    System.getProperty("scala.version", "unknown version");
-  val versionMsg = PRODUCT + " " + VERSION + " -- (c) 2002-05 LAMP/EPFL";
-  val prompt = "\nnsc> ";
-
-  private var reporter: ConsoleReporter = _;
-
-  def error(msg: String): unit =
-    reporter.error(new Position(PRODUCT),
-                   msg + "\n  " + PRODUCT + " -help  gives more information");
-
-  def errors() = reporter.errors;
-
-  def interpret(gCompiler: Global): unit = {
-    val interpreter = new Interpreter {
-      val compiler: gCompiler.type = gCompiler
-    };
-    loop(line => try {
-        interpreter.interpret(line.trim(), reporter)
-      } catch {
-        case e: Exception => {
-          reporter.info(null,e.getMessage(),true);
-          //e.printStackTrace();
-        }
+object MainInterpreter {
+  val reporter = new ConsoleReporter()
+
+  var interpreter: Interpreter = _
+
+  /** print a friendly help message */
+  def printHelp = {
+    Console.println("This is an interpreter for Scala.")
+    Console.println("Type in expressions to have them evaluated.")
+    Console.println("Type :quit to exit the interpreter.")
+    Console.println("Type :compile followed by a filename to compile a complete Scala file.")
+    Console.println("Type :load followed by a filename to load a sequence of interpreter commands.")
+    Console.println("Type :help to repeat this message later.")
+  }
+
+  /** A simple, generic read-eval-print loop with a pluggable eval-print function.
+      Loop reading lines of input and invoking the eval-print function.
+      Stop looping when eval-print returns false.  */
+  def repl(evpr: String => Boolean): Unit = {
+    val in = new BufferedReader(new InputStreamReader(System.in))
+
+    while(true) {
+      Console.print("\nscala> ")
+      var line = in.readLine()
+			if(line == null)
+        return ()  // assumes null means EOF
+
+      val keepGoing = evpr(line)
+
+      if(!keepGoing)
+        return ()  // the evpr function said to stop
+    }
+  }
+
+  /** interpret one line of code submitted by the user */
+  def interpretOne(line: String): Unit = {
+    try {
+      interpreter.interpret(line)
+     } catch {
+       case e: Exception => {
+         reporter.info(null,"Exception occurred: " + e.getMessage(),true)
+         //e.printStackTrace()
+       }
+     }
+  }
+
+  /** interpret all lines from a specified file */
+  def interpretAllFrom(filename: String): Unit = {
+    val fileIn = try {
+      new FileReader(filename)
+    } catch {
+      case _:IOException =>
+          Console.println("Error opening file: " + filename)
+          null
+    }
+    if(fileIn == null) return ()
+    val in = new BufferedReader(fileIn)
+    while(true) {
+      val line = in.readLine
+      if(line == null) {
+        fileIn.close
+        return ()
       }
-    )
+      command(line)
+    }
   }
 
-  def process(args: Array[String]): unit = {
-    reporter = new ConsoleReporter();
-    val command = new CompilerCommand(List.fromArray(args), error, false);
-    reporter.prompt = (command.settings.prompt.value);
-    if (command.settings.version.value)
-      reporter.info(null, versionMsg, true)
-    else if (command.settings.help.value) // 2do replace with InterpCommand
-      reporter.info(null, command.usageMsg, true)
+  /** run one command submitted by the user */
+  def command(line: String): Boolean = {
+    def withFile(command: String)(action: String=>Unit): Unit = {
+      val spaceIdx = command.indexOf(' ')
+      if(spaceIdx <= 0) {
+        Console.println("That command requires a filename to be specified.")
+        return ()
+      }
+      val filename = command.substring(spaceIdx).trim
+      action(filename)
+    }
 
-    else {
-      try {
-        val compiler = new Global(command.settings, reporter);
-        interpret(compiler);
-      } catch {
-  case ex @ FatalError(msg) =>
-    if (command.settings.debug.value)
-      ex.printStackTrace();
-    reporter.error(null, "fatal error: " + msg);
+    if(line.startsWith(":"))
+      line match {
+        case ":help" => printHelp
+        case ":quit" => return false
+        case _ if line.startsWith(":compile") => withFile(line)(f => interpreter.compile(f))
+        case _ if line.startsWith(":load") => withFile(line)(f => interpretAllFrom(f))
+        case _ => Console.println("Unknown command.  Type :help for help.")
       }
-      reporter.printSummary()
+    else
+      interpretOne(line)
+    true
+  }
+
+
+
+  /** the main interpreter loop */
+  def interpretLoop(compiler: Global): unit = {
+    interpreter = new Interpreter(compiler, str=>Console.print(str))
+    repl(command)
+    interpreter.close
+  }
+
+
+
+  /** process the command-line arguments and do as they request */
+  def process(args: Array[String]): unit = {
+    val command = new CompilerCommand(List.fromArray(args), error, false)
+    reporter.prompt = command.settings.prompt.value
+    if (command.settings.help.value) {
+      reporter.info(null, command.usageMsg, true)
+    } else {
+      printHelp
+      interpretLoop(new Global(command.settings, reporter))
     }
   }
 
   def main(args: Array[String]): unit = {
-    process(args);
-    System.exit(if (reporter.errors > 0) 1 else 0);
+    process(args)
   }
-
 }