coproduct reader

build.sbt

@@ -52,8 +52,7 @@ lazy val commonSettings = Seq(
     "-Ywarn-unused:params",              // Warn if a value parameter is unused.
     "-Ywarn-unused:patvars",             // Warn if a variable bound in a pattern is unused.
     "-Ywarn-unused:privates",            // Warn if a private member is unused.
-    "-Ywarn-value-discard",              // Warn when non-Unit expression results are unused.
-    "-language:reflectiveCalls"
+    "-Ywarn-value-discard"               // Warn when non-Unit expression results are unused.
   ),
   libraryDependencies += "org.scalatest" %% "scalatest" % "3.0.2" % Test,
   updateImpactOpenBrowser := false

core/src/main/scala/better/files/Scanner.scala

@@ -46,7 +46,7 @@ object Scanner {
     override def close() = reader.close()
   }
 
-  val stdin = Scanner(System.in)(Config.default)
+  val stdin: Scanner = Scanner(System.in)(Config.default)
 
   /**
     * Use this to configure your Scanner

core/src/main/scala/better/files/package.scala

@@ -12,7 +12,7 @@ package object files extends Implicits {
     * Default array buffer size
     * Seems like a good value used by JDK: (see: java.io.BufferedInputStream.DEFAULT_BUFFER_SIZE)
     */
-  private[files] val defaultBufferSize = 8192
+  val defaultBufferSize = 8192
 
   /**
     * The default charset used by better-files

shapeless/src/main/scala/better/files/ShapelessScanner.scala

@@ -1,7 +1,11 @@
 package better.files
 
+import better.files.Scanner.Read
+
 import shapeless._
 
+import scala.util.Try
+
 object ShapelessScanner {
   implicit val hNilScannable: Scannable[HNil] =
     Scannable(_ => HNil)
@@ -11,4 +15,10 @@ object ShapelessScanner {
 
   implicit def genericScannable[A, R](implicit gen: Generic.Aux[A, R], reprScannable: Lazy[Scannable[R]]): Scannable[A] =
     Scannable(s => gen.from(reprScannable.value(s)))
+
+  implicit val cnilReader: Read[CNil] =
+    Read(_ => throw new IllegalStateException())
+
+  implicit def coproductReader[H, T <: Coproduct](implicit h: Read[H], t: Read[T]): Read[H :+: T] =
+    Read(s => Try(Inl(h(s))).getOrElse(Inr(t(s))))
 }