From 079230a5d45cdfcc30fc00af595e842883ad2047 Mon Sep 17 00:00:00 2001
From: markhibberd <mark@hibberd.id.au>
Date: Wed, 22 Jan 2014 09:34:30 +1100
Subject: [PATCH] Expose CursorOp for via pattern matching and fold.

This is is not ideal, but fixes #79 with breaking compatability, will revisit for 6.1
---
 project/build.scala                    | 19 +++++++++++++++----
 project/plugins.sbt                    |  2 ++
 src/main/scala/argonaut/CursorOp.scala | 13 +++++++++++--
 3 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/project/build.scala b/project/build.scala
index be0e906b..660f5889 100644
--- a/project/build.scala
+++ b/project/build.scala
@@ -4,6 +4,10 @@ import com.typesafe.sbt.pgp.PgpKeys._
 import Tools.onVersion
 import sbtrelease.ReleasePlugin._
 
+import com.typesafe.tools.mima.plugin.MimaPlugin.mimaDefaultSettings
+import com.typesafe.tools.mima.plugin.MimaKeys.previousArtifact
+import com.typesafe.tools.mima.plugin.MimaKeys.binaryIssueFilters
+
 object build extends Build {
   type Sett = Project.Setting[_]
 
@@ -11,9 +15,9 @@ object build extends Build {
       organization := "io.argonaut"
   )
 
-  val scalaz = "org.scalaz" %% "scalaz-core" % "7.0.3"
-  val scalacheck = "org.scalacheck" %% "scalacheck" % "1.10.0" % "test"
-  val scalazScalaCheckBinding = "org.scalaz" %% "scalaz-scalacheck-binding" % "7.0.3" % "test"
+  val scalaz = "org.scalaz" %% "scalaz-core" % "7.0.5"
+  val scalacheck = "org.scalacheck" %% "scalacheck" % "1.10.1" % "test"
+  val scalazScalaCheckBinding = "org.scalaz" %% "scalaz-scalacheck-binding" % "7.0.5" % "test"
   val specs2_1_12_4_1 = "org.specs2" %% "specs2" % "1.12.4.1" % "test"
   val specs2_1_14 = "org.specs2" %% "specs2" % "1.14" % "test"
   val caliper = "com.google.caliper" % "caliper" % "0.5-rc1"
@@ -24,7 +28,7 @@ object build extends Build {
   val argonaut = Project(
     id = "argonaut"
   , base = file(".")
-  , settings = base ++ ReplSettings.all ++ releaseSettings ++ PublishSettings.all ++ InfoSettings.all ++ Seq[Sett](
+  , settings = base ++ ReplSettings.all ++ releaseSettings ++ PublishSettings.all ++ InfoSettings.all ++ mimaDefaultSettings ++ Seq[Sett](
       name := "argonaut"
     , (sourceGenerators in Compile) <+= (sourceManaged in Compile) map Boilerplate.gen
     , libraryDependencies <++= onVersion(
@@ -32,6 +36,13 @@ object build extends Build {
       , on292 = Seq(specs2_1_12_4_1)
       , on210 = Seq(specs2_1_14)
       )
+    , previousArtifact <<= (organization, name, scalaBinaryVersion) { (o, n, sbv) => Some(o % (n + "_" + sbv) % "6.0.1") }
+    , binaryIssueFilters ++= {
+      import com.typesafe.tools.mima.core._
+      import com.typesafe.tools.mima.core.ProblemFilters._
+      Seq(
+        "argonaut.CursorOp.fold"
+      ) map exclude[MissingMethodProblem] }
     )
   )
 
diff --git a/project/plugins.sbt b/project/plugins.sbt
index eaecbd8a..6dc2caaf 100644
--- a/project/plugins.sbt
+++ b/project/plugins.sbt
@@ -3,3 +3,5 @@ addSbtPlugin(("com.typesafe.sbt" % "sbt-pgp" % "0.7").cross(CrossVersion.full))
 addSbtPlugin("com.github.mpeltonen" % "sbt-idea" % "1.2.0")
 
 addSbtPlugin("com.github.gseitz" % "sbt-release" % "0.7")
+
+addSbtPlugin("com.typesafe" % "sbt-mima-plugin" % "0.1.4")
diff --git a/src/main/scala/argonaut/CursorOp.scala b/src/main/scala/argonaut/CursorOp.scala
index 45a83b26..ccebc948 100644
--- a/src/main/scala/argonaut/CursorOp.scala
+++ b/src/main/scala/argonaut/CursorOp.scala
@@ -3,6 +3,14 @@ package argonaut
 import scalaz._, Scalaz._
 
 sealed trait CursorOp {
+  def fold[X](reattempt: => X, el: (CursorOpElement, Boolean) => X) =
+    this match {
+      case Reattempt =>
+        reattempt
+      case El(op, success) =>
+        el(op, success)
+    }
+
   def isReattempt: Boolean =
     this == Reattempt
 
@@ -21,8 +29,9 @@ sealed trait CursorOp {
       case El(_, s) => !s
     }
 }
-private case object Reattempt extends CursorOp
-private case class El(o: CursorOpElement, success: Boolean) extends CursorOp
+
+case object Reattempt extends CursorOp
+case class El(o: CursorOpElement, success: Boolean) extends CursorOp
 
 object CursorOp extends CursorOps {
   def apply(o: CursorOpElement): CursorOp =