Added the ability to bind values to the REPL

potencia · May 28, 2022 · ced0627 · ced0627
1 parent a644f95
commit ced0627
Show file tree

Hide file tree

Showing 3 changed files with 57 additions and 11 deletions.
diff --git a/src/main/scala/com/potenciasoftware/rebel/BaseRepl.scala b/src/main/scala/com/potenciasoftware/rebel/BaseRepl.scala
@@ -1,8 +1,12 @@
 package com.potenciasoftware.rebel
 
+import scala.reflect.ClassTag
+import scala.reflect.runtime.universe.TypeTag
 import scala.tools.nsc.Settings
+import scala.tools.nsc.interpreter.Repl
 import scala.tools.nsc.interpreter.shell.ILoop
 import scala.tools.nsc.interpreter.shell.ShellConfig
+import scala.tools.nsc.typechecker.TypeStrings
 
 import BaseRepl._
 
@@ -36,13 +40,26 @@ class BaseRepl {
   /** Override to provide banner text to display at startup. */
   protected val banner: String = WelcomePlaceholder
 
-  protected def config: ShellConfig = ShellConfig(settings)
+  /**
+   * Override to provide bound values.
+   * These will be available from within the REPL.
+   */
+  protected def boundValues: Seq[Parameter] = Seq()
+
+  private lazy val repl: ILoop = new ILoop(ShellConfig(settings)) {
 
-  protected def repl: ILoop = new ILoop(config) {
     val _banner = Option(banner).getOrElse(WelcomePlaceholder)
     override def welcome: String = {
       _banner.replaceAll(WelcomePlaceholder, super.welcome)
     }
+
+    override def createInterpreter(interpreterSettings: Settings): Unit = {
+      super.createInterpreter(interpreterSettings)
+      intp.beQuietDuring {
+        for (param <- boundValues)
+          param.bindTo(intp)
+      }
+    }
   }
 
   def run(): Unit = {
@@ -52,4 +69,19 @@ class BaseRepl {
 
 object BaseRepl {
   private val WelcomePlaceholder = "%%%%welcome%%%%"
+
+  class Parameter private (
+    name: String,
+    `type`: String,
+    value: Any,
+    modifiers: List[String]
+  ) {
+    private[BaseRepl] def bindTo(intp: Repl): Unit =
+      intp.bind(name, `type`, value, modifiers)
+  }
+
+  object Parameter {
+    def apply[A: TypeTag: ClassTag](name: String, value: A, modifiers: String*) =
+      new Parameter(name, TypeStrings.fromTag[A], value, modifiers.toList)
+  }
 }
diff --git a/src/test/scala/com/potenciasoftware/rebel/BaseReplTest.scala b/src/test/scala/com/potenciasoftware/rebel/BaseReplTest.scala
@@ -7,23 +7,24 @@ import scala.tools.nsc.Settings
 import scala.tools.nsc.interpreter.shell.ILoop
 import scala.tools.nsc.interpreter.shell.ShellConfig
 
-import TestUtils._
+import BaseRepl.Parameter
 import BaseReplTest._
+import TestUtils._
 
 class BaseReplTest extends AnyFlatSpec with Matchers {
 
   def basic() = new TestRepl()
 
   "BaseRepl" should "behave like the normal ILoop" in {
-    replTest[BaseReplTest]("basic", Seq("42 + 42"))
+    replTest[BaseReplTest]("basic", "42 + 42")
       .out.asBlock shouldBe """
       |scala> val res0: Int = 84
       |
       |scala> """.stripMargin
   }
 
   it should "have the default compiler options" in {
-    replTest[BaseReplTest]("basic", Seq("def test(): Int = 1", "test")).out(3) shouldBe
+    replTest[BaseReplTest]("basic", "def test(): Int = 1", "test").out(3) shouldBe
       "scala> warning: 1 deprecation (since 2.13.3); for details, " +
       "enable `:setting -deprecation` or `:replay -deprecation`"
   }
@@ -37,7 +38,7 @@ class BaseReplTest extends AnyFlatSpec with Matchers {
   }
 
   it should "set custom compiler options" in {
-    replTest[BaseReplTest]("customCompilerOptions", Seq("def test(): Int = 1", "test"))
+    replTest[BaseReplTest]("customCompilerOptions", "def test(): Int = 1", "test")
       .out.drop(2).take(3).asBlock shouldBe
       """
       |scala> val res0: Int = 1
@@ -47,18 +48,31 @@ class BaseReplTest extends AnyFlatSpec with Matchers {
   def defaultBanner() = new BaseRepl()
 
   it should "display the standard ILoop banner by default" in {
-    replTest[BaseReplTest]("defaultBanner", Seq())
+    replTest[BaseReplTest]("defaultBanner")
       .out.takeWhile(_ != "scala> ").asBlock shouldBe
       s"${new ILoop(ShellConfig(new Settings)).welcome}\n"
   }
 
+  def customBanner() = new BaseRepl() {
+    override protected val banner: String = "Custom Banner"
+  }
+
   it should "display a custom banner" in {
-    replTest[BaseReplTest]("customBanner", Seq())
+    replTest[BaseReplTest]("customBanner")
       .out.takeWhile(_ != "scala> ").asBlock shouldBe "Custom Banner\n"
   }
 
-  def customBanner() = new BaseRepl() {
-    override protected val banner: String = "Custom Banner"
+  def boundAnswer() = new TestRepl {
+
+    private val Answer: Int = 42
+
+    override protected def boundValues: Seq[Parameter] =
+      Seq(Parameter("Answer", Answer))
+  }
+
+  it should "bind custom variables" in {
+    replTest[BaseReplTest]("boundAnswer", "println(Answer)")
+      .out(1) shouldBe "scala> println(Answer)42"
   }
 }
 

diff --git a/src/test/scala/com/potenciasoftware/rebel/TestUtils.scala b/src/test/scala/com/potenciasoftware/rebel/TestUtils.scala
@@ -83,7 +83,7 @@ object TestUtils {
     *                   (Note: including a [[":q"]] line at the end of the input
     *                   is not necessary.)
     */
-  def replTest[C: ClassTag](methodName: String, inputLines: Iterable[String]): RunResults = {
+  def replTest[C: ClassTag](methodName: String, inputLines: String*): RunResults = {
     import scala.sys.process._
 
     val in = new InputLinesStream(inputLines ++ Seq(":q"))