Goofing around with embedding the scala REPL inside a sbt project

build.sbt

import Dependencies._

lazy val root = (project in file(".")).
  settings(
    inThisBuild(List(
      organization := "com.example",
      scalaVersion := "2.12.1",
      version      := "0.1.0-SNAPSHOT"
    )),
    name := "Hello",
    libraryDependencies ++= Seq(
        scalaTest % Test,
        scalaCompiler,
        jline
//        ammonite
    )
  )

Dependencies.scala

import sbt._

// project/Dependencies.scala

object Dependencies {
  lazy val scalaTest = "org.scalatest" %% "scalatest" % "3.0.1"
//  lazy val ammonite  = "com.lihaoyi" %% "ammonite" % "1.0.0" cross CrossVersion.full
//  lazy val scalaCompiler  = "org.scala-lang" % "scala-compiler" % scalaVersion.value
  lazy val scalaCompiler  = "org.scala-lang" % "scala-compiler" % "2.12.1"
  lazy val jline = "org.scala-lang.modules" % "scala-jline" % "2.12.1"
}

Hello.scala

package example

// src/main/scala/example/Hello.scala

// import scala.reflect.ClassTag
import scala.tools.nsc.Settings
import scala.tools.nsc.interpreter.{ILoop, NamedParam}
//import ammonite._

trait Greeting {
  lazy val greeting: String = "hello"
}

// Ammonite v1 example
// object Hello extends Greeting with App {
//   def dude(name: String) = {
//     println(s"Howdy, ${name} !")
//   }
//   ammonite.Main( predefCode = "println(\"Starting Debugging\")" ).run( "dude" -> dude _ )
//   println(greeting)
// }

// Ammonite v2 example
// object Hello extends Greeting {
//   def dude(name: String) = {
//     println(s"Howdy, ${name} !")
//   }
//
//   def main(args: Array[String]) {
//     println(greeting)
//     ammonite.Main( predefCode = "println(\"Starting Debugging\")" ).run( "dude" -> dude _ )
//     dude("Frank")
//   }
// }

/* crap */

// // basic repl integration (why can't I get these to work with scala 2.12.x ?!?!?!)
// // https://stackoverflow.com/questions/40322771/iloop-tab-completion
// // https://stackoverflow.com/questions/18628516/embedded-scala-repl-interpreter-example-for-2-10
// // https://stackoverflow.com/questions/18628516/embedded-scala-repl-interpreter-example-for-2-10/18628517#18628517
// // http://techqa.info/programming/question/18628516/embedded-scala-repl-interpreter-example-for-2.10
// // https://groups.google.com/forum/#!topic/scala-internals/bM_2ze5QMXY
// // https://stackoverflow.com/questions/16920884/custom-scala-repl-issues
// // https://stackoverflow.com/questions/8916699/how-to-write-scala-2-9-code-that-will-allow-dropping-into-an-interpreter
// // https://stackoverflow.com/questions/2160355/drop-into-interpreter-during-arbitrary-scala-code-location
// // http://www.scala-lang.org/api/2.12.2/scala-compiler/scala/tools/nsc/interpreter/ILoop.html
// object Hello extends Greeting with App {
//   val ss = new Settings {
// //    usejavacp.value = true
//     deprecation.value = true
//     Yreplsync.value = true
//   }
//
//   def repl = new ILoop {
//     override def createInterpreter(): Unit = {
//       super.createInterpreter()
//     }
//   }
//
//   def dude(name: String) = {
//     println(s"Howdy, ${name} !")
//   }
//
//   println(greeting)
//   ss.embeddedDefaults[Hello.type]
//   repl.process(ss)
//   dude("Frank")
// }

// object Hello extends Greeting with App {
//   def breakIf[T](assertion: => Boolean, args: NamedParam*)(implicit tag: ClassTag[T]) = {
//     // val repl = new ILoop() {
//     //   override protected def postInitialization(): Unit = {
//     //     addThunk(args.foreach(p => intp.bind(p)))
//     //     //super.postInitialization()
//     //   }
//     // }
//     val repl = new ILoop() {
//       override def printWelcome() = {
//         processLine("")
//         super.printWelcome()
//         echo("Customized...")
//       }
//     }
//
//     val settings = new Settings()
//
//     settings.Yreplsync.value = true
//     settings.usejavacp.value = true
//     settings.embeddedDefaults[T]
//
// //    args.foreach(repl.intp.rebind)
//
//     repl.process(settings)
//   }
//
//   def dude(name: String) = {
//     println(s"Howdy, ${name} !")
//   }
//
//   println(greeting)
//   breakIf[App](assertion = true, NamedParam("greeting", greeting))
//   dude("Frank")
// }

// object Hello extends Greeting with App {
//   def repl = new ILoop {
//     override def loop(): Unit = {
//       intp.bind("e", "Double", 2.71828)
//       super.loop()
//     }
//   }
//
//   val settings = new Settings
//   settings.Yreplsync.value = true
//
//   // the 'usejavacp' setting when launching within SBT
//   settings.embeddedDefaults[Repl.type]
//
//   def dude(name: String) = {
//     repl.process(settings)
//     println(s"Howdy, ${name} !")
//   }
//
//   println(greeting)
//   dude("Frank")
// }