diff options
Diffstat (limited to 'src/repl/scala/tools/nsc/interpreter/InteractiveReader.scala')
-rw-r--r-- | src/repl/scala/tools/nsc/interpreter/InteractiveReader.scala | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/src/repl/scala/tools/nsc/interpreter/InteractiveReader.scala b/src/repl/scala/tools/nsc/interpreter/InteractiveReader.scala index 71753a3e39..1f81d9965c 100644 --- a/src/repl/scala/tools/nsc/interpreter/InteractiveReader.scala +++ b/src/repl/scala/tools/nsc/interpreter/InteractiveReader.scala @@ -50,3 +50,98 @@ object InteractiveReader { def createDefault(): InteractiveReader = apply() // used by sbt } +/** Collect one line of user input from the supplied reader. + * Runs on a new thread while the REPL is initializing on the main thread. + * + * The user can enter text or a `:paste` command. + */ +class SplashLoop(reader: InteractiveReader, prompt: String) extends Runnable { + import java.util.concurrent.SynchronousQueue + import scala.compat.Platform.EOL + + private val result = new SynchronousQueue[Option[String]] + @volatile private var running: Boolean = _ + private var thread: Thread = _ + + /** Read one line of input which can be retrieved with `line`. */ + def run(): Unit = { + var line = "" + try + do { + line = reader.readLine(prompt) + if (line != null) { + line = process(line.trim) + } + } while (line != null && line.isEmpty && running) + finally { + result.put(Option(line)) + } + } + + /** Check for `:paste` command. */ + private def process(line: String): String = { + def isPrefix(s: String, p: String, n: Int) = ( + //s != null && p.inits.takeWhile(_.length >= n).exists(s == _) + s != null && s.length >= n && s.length <= p.length && s == p.take(s.length) + ) + if (isPrefix(line, ":paste", 3)) { + // while collecting lines, check running flag + var help = f"// Entering paste mode (ctrl-D to finish)%n%n" + def readWhile(cond: String => Boolean) = { + Iterator continually reader.readLine(help) takeWhile { x => + help = "" + x != null && cond(x) + } + } + val text = (readWhile(_ => running) mkString EOL).trim + val next = + if (text.isEmpty) "// Nothing pasted, nothing gained." + else "// Exiting paste mode, now interpreting." + Console println f"%n${next}%n" + text + } else { + line + } + } + + def start(): Unit = result.synchronized { + require(thread == null, "Already started") + thread = new Thread(this) + running = true + thread.start() + } + + def stop(): Unit = result.synchronized { + running = false + if (thread != null) thread.interrupt() + thread = null + } + + /** Block for the result line, or null on ctl-D. */ + def line: String = result.take getOrElse null +} +object SplashLoop { + def apply(reader: SplashReader, prompt: String): SplashLoop = new SplashLoop(reader, prompt) +} + +/** Reader during splash. Handles splash-completion with a stub, otherwise delegates. */ +class SplashReader(reader: InteractiveReader, postIniter: InteractiveReader => Unit) extends InteractiveReader { + /** Invoke the postInit action with the underlying reader. */ + override def postInit(): Unit = postIniter(reader) + + override val interactive: Boolean = reader.interactive + + override def reset(): Unit = reader.reset() + override def history: History = reader.history + override val completion: Completion = NoCompletion + override def redrawLine(): Unit = reader.redrawLine() + + override protected[interpreter] def readOneLine(prompt: String): String = ??? // unused + override protected[interpreter] def readOneKey(prompt: String): Int = ??? // unused + + override def readLine(prompt: String): String = reader.readLine(prompt) +} +object SplashReader { + def apply(reader: InteractiveReader)(postIniter: InteractiveReader => Unit) = + new SplashReader(reader, postIniter) +} |