REPL: open up for extensibility

compiler/src/dotty/tools/repl/JLineTerminal.scala

@@ -16,7 +16,7 @@ import org.jline.reader.impl.history.DefaultHistory
 import org.jline.terminal.TerminalBuilder
 import org.jline.utils.AttributedString
 
-final class JLineTerminal extends java.io.Closeable {
+class JLineTerminal extends java.io.Closeable {
   // import java.util.logging.{Logger, Level}
   // Logger.getLogger("org.jline").setLevel(Level.FINEST)
 
@@ -30,7 +30,8 @@ final class JLineTerminal extends java.io.Closeable {
   private def blue(str: String)(using Context) =
     if (ctx.settings.color.value != "never") Console.BLUE + str + Console.RESET
     else str
-  private def prompt(using Context)        = blue("\nscala> ")
+  protected def promptStr = "scala"
+  private def prompt(using Context)        = blue(s"\n$promptStr> ")
   private def newLinePrompt(using Context) = blue("     | ")
 
   /** Blockingly read line from `System.in`

compiler/src/dotty/tools/repl/Rendering.scala

@@ -28,10 +28,10 @@ private[repl] class Rendering(parentClassLoader: Option[ClassLoader] = None):
 
   import Rendering._
 
-  private var myClassLoader: AbstractFileClassLoader = _
+  var myClassLoader: AbstractFileClassLoader = _
 
   /** (value, maxElements, maxCharacters) => String */
-  private var myReplStringOf: (Object, Int, Int) => String = _
+  var myReplStringOf: (Object, Int, Int) => String = _
 
   /** Class loader used to load compiled code */
   private[repl] def classLoader()(using Context) =

compiler/src/dotty/tools/repl/ReplDriver.scala

@@ -118,7 +118,7 @@ class ReplDriver(settings: Array[String],
   private var rootCtx: Context = _
   private var shouldStart: Boolean = _
   private var compiler: ReplCompiler = _
-  private var rendering: Rendering = _
+  protected var rendering: Rendering = _
 
   // initialize the REPL session as part of the constructor so that once `run`
   // is called, we're in business
@@ -138,7 +138,7 @@ class ReplDriver(settings: Array[String],
    *  observable outside of the CLI, for this reason, most helper methods are
    *  `protected final` to facilitate testing.
    */
-  final def runUntilQuit(using initialState: State = initialState)(): State = {
+  def runUntilQuit(using initialState: State = initialState)(): State = {
     val terminal = new JLineTerminal
 
     out.println(
@@ -176,7 +176,12 @@ class ReplDriver(settings: Array[String],
     interpret(ParseResult.complete(input))
   }
 
-  private def runBody(body: => State): State = rendering.classLoader()(using rootCtx).asContext(withRedirectedOutput(body))
+  final def runQuietly(input: String)(using State): State = runBody {
+    val parsed = ParseResult(input)
+    interpret(parsed, quiet = true)
+  }
+
+  protected def runBody(body: => State): State = rendering.classLoader()(using rootCtx).asContext(withRedirectedOutput(body))
 
   // TODO: i5069
   final def bind(name: String, value: Any)(using state: State): State = state
@@ -242,10 +247,10 @@ class ReplDriver(settings: Array[String],
         .getOrElse(Nil)
   end completions
 
-  private def interpret(res: ParseResult)(using state: State): State = {
+  protected def interpret(res: ParseResult, quiet: Boolean = false)(using state: State): State = {
     res match {
       case parsed: Parsed if parsed.trees.nonEmpty =>
-        compile(parsed, state)
+        compile(parsed, state, quiet)
 
       case SyntaxErrors(_, errs, _) =>
         displayErrors(errs)
@@ -263,7 +268,7 @@ class ReplDriver(settings: Array[String],
   }
 
   /** Compile `parsed` trees and evolve `state` in accordance */
-  private def compile(parsed: Parsed, istate: State): State = {
+  private def compile(parsed: Parsed, istate: State, quiet: Boolean = false): State = {
     def extractNewestWrapper(tree: untpd.Tree): Name = tree match {
       case PackageDef(_, (obj: untpd.ModuleDef) :: Nil) => obj.name.moduleClassName
       case _ => nme.NO_NAME
@@ -314,9 +319,11 @@ class ReplDriver(settings: Array[String],
               given Ordering[Diagnostic] =
                 Ordering[(Int, Int, Int)].on(d => (d.pos.line, -d.level, d.pos.column))
 
-              (definitions ++ warnings)
-                .sorted
-                .foreach(printDiagnostic)
+              if (!quiet) {
+                (definitions ++ warnings)
+                  .sorted
+                  .foreach(printDiagnostic)
+              }
 
               updatedState
             }