Make method 'nestedApplications' public (#345)

kernel/src/main/scala/me/rexim/morganey/ast/LambdaTerm.scala

@@ -104,7 +104,7 @@ case class LambdaApp(leftTerm: LambdaTerm, rightTerm: LambdaTerm) extends Lambda
   override val freeVars: Set[String] = leftTerm.freeVars ++ rightTerm.freeVars
 
   @tailrec
-  private[ast] final def nestedApplications(acc: List[LambdaTerm] = Nil): (LambdaTerm, List[LambdaTerm]) =
+  final def nestedApplications(acc: List[LambdaTerm] = Nil): (LambdaTerm, List[LambdaTerm]) =
     leftTerm match {
       case l: LambdaApp => l.nestedApplications(rightTerm :: acc)
       case _            => (leftTerm, rightTerm :: acc)

kernel/src/test/scala/me/rexim/morganey/ast/LambdaTermSpec.scala

@@ -0,0 +1,22 @@
+package me.rexim.morganey.ast
+
+import me.rexim.morganey.ast.LambdaTermHelpers._
+import me.rexim.morganey.helpers.TestTerms
+import org.scalatest.{FlatSpec, Matchers}
+
+class LambdaTermSpec extends FlatSpec with Matchers with TestTerms {
+
+  behavior of "A lambda application"
+
+  it should "be able to extract the nested applications" in {
+
+    def nestedApps(n: Int): LambdaApp =
+      (1 until n).map(_ => d).foldLeft(lapp(x, d))(lapp)
+
+    nestedApps(1).nestedApplications() should be (x, List(d))
+    nestedApps(2).nestedApplications() should be (x, List(d, d))
+    nestedApps(5).nestedApplications() should be (x, List(d, d, d, d, d))
+
+  }
+
+}