Add methods to convert from Managed into scala.util.Try

- Some TLC on ExtractedEither
- Update apply method to use supressed exceptions
  (when you can only through/send one exception, might as well,
   just prefer keeping them in Either until necessary).
- Added tests for scala.util.Try conversion.

Author: jsuereth

src/main/scala/resource/AbstractManagedResource.scala

@@ -30,6 +30,8 @@ private[resource] class DeferredExtractableManagedResource[+A,R](val resource: M
 
   override def opt = either.either.right.toOption
 
+  override def tried = scala.util.Try(resource apply translate)
+
   override def equals(that: Any) = that match {
     case x : DeferredExtractableManagedResource[A,R] => (x.resource == resource) && (x.translate == translate)
     case _ => false

src/main/scala/resource/ExtractableManagedResource.scala

@@ -14,6 +14,7 @@
 package resource
 
 import collection.Seq
+import util.Try
 
 /**
  * This trait represents a resource that has been modified (or will be modified) inside an ARM block in such
@@ -47,6 +48,17 @@ trait ExtractableManagedResource[+A] extends ManagedResource[A] {
    *        the right hand side will contain the sequence of throwable encountered.
    */
   def either: ExtractedEither[Seq[Throwable], A]
-}
 
-case class ExtractedEither[+A, +B](either: Either[A, B])
+  /**
+   * This method is used to extract the resource being managed.
+   *
+   * This allows you to pull information out of the Managed resource, as such, the reosurce will not be "available"
+   * after this method call.
+   *
+   * @returns
+   *        A [[scala.util.Try]] instance, which is [[scala.util.Success]] if there were no exceptions pulling out the 
+   *        resource, or a [[scala.util.Failure]] if there were.  In the event of multiple failures, they will
+   *        be added to the supressed exception list of the resulting Failure.
+   */
+  def tried: Try[A]
+}

src/main/scala/resource/ExtractedEither.scala

@@ -0,0 +1,18 @@
+// -----------------------------------------------------------------------------
+//
+//  scala.arm - The Scala Incubator Project
+//  Copyright (c) 2009 and onwards The Scala Incubator Project. All rights reserved.
+//
+//  The primary distribution site is http://jsuereth.github.com/scala-arm
+//
+//  This software is released under the terms of the Revised BSD License.
+//  There is NO WARRANTY.  See the file LICENSE for the full text.
+//
+// -----------------------------------------------------------------------------
+package resource
+
+
+/**
+ *  This is a helper class to work around `Either` pattern matching issues.
+ */
+case class ExtractedEither[+A, +B](either: Either[A, B])

src/main/scala/resource/ManagedResourceOperations.scala

@@ -23,7 +23,12 @@ import _root_.scala.concurrent.{ ExecutionContext, Future }
 trait ManagedResourceOperations[+R] extends ManagedResource[R] { self =>
   //TODO - Can we always grab the top exception?
   override def acquireAndGet[B](f: R => B): B = apply(f)
-  override def apply[B](f: R => B): B = acquireFor(f).fold( liste => throw liste.head, x => x)
+  override def apply[B](f: R => B): B = acquireFor(f).fold( 
+    liste => throw liste reduce { (prev, next) =>
+      prev.addSuppressed(next)
+      prev
+    }, 
+    x => x)
 
   override def toTraversable[B](implicit ev: R <:< TraversableOnce[B]): Traversable[B] = 
     new ManagedTraversable[B,R] {

src/test/scala/resource/TestManagedResource.scala

@@ -454,4 +454,30 @@ class TestManagedResource {
     assertEquals("Failure result", "KO", result)
     assertFalse("Failed to close resource", r.isOpened)
   }
+
+
+    @Test
+  def mustBeSuccessTry() {
+    val r = new FakeResource()
+
+    assertFalse("Failed to begin closed!", r.isOpened)
+    val result = managed(r).map[String](_ => "OK").tried
+    assertTrue("Successful result", result.isSuccess)
+    assertFalse("Failed to close resource", r.isOpened)
+  }
+
+  @Test
+  def mustBeFailedTry() {
+    val r = new FakeResource()
+
+    assertFalse("Failed to begin closed!", r.isOpened)
+
+    val result = managed(r).map[String](_ => {
+        sys.error("Error")
+        "OK"
+      }).tried
+
+    assertFalse("Failure result", result.isSuccess)
+    assertFalse("Failed to close resource", r.isOpened)
+  }
 }