smallish code cleanup and more documentation

3 files changed, 14 insertions, 17 deletions

diff --git a/src/main/scala/cc/spray/json/lenses/Projection.scala b/src/main/scala/cc/spray/json/lenses/Projection.scala
index fe44115..7f17886 100644
--- a/src/main/scala/cc/spray/json/lenses/Projection.scala
+++ b/src/main/scala/cc/spray/json/lenses/Projection.scala
@@ -4,9 +4,14 @@ package lenses
 /**
  * A projection combines read and update functions of UpdateLens and ReadLens into
  * combinable chunks.
- * @tparam M
+ *
+ * A projection can either operate on a scalar value, or on an optional value, or on a
+ * sequence value. This is denoted by the `M[_]` type constructor.
  */
 trait Projection[M[_]] extends UpdateLens with ReadLens[M] {
+  /**
+   * Combines two projections.
+   */
   def /[M2[_], R[_]](next: Projection[M2])(implicit ev: Join[M2, M, R]): Projection[R]
 
   def toSeq: Projection[Seq]
diff --git a/src/main/scala/cc/spray/json/lenses/ScalarLenses.scala b/src/main/scala/cc/spray/json/lenses/ScalarLenses.scala
index 05d8657..12419ec 100644
--- a/src/main/scala/cc/spray/json/lenses/ScalarLenses.scala
+++ b/src/main/scala/cc/spray/json/lenses/ScalarLenses.scala
@@ -4,24 +4,17 @@ package lenses
 trait ScalarLenses {
   def field(name: String): ScalarProjection = new Proj[Id] {
     def updated(f: SafeJsValue => SafeJsValue)(parent: JsValue): SafeJsValue =
-      for {
-        res <- f(getField(parent))
-      }
-      yield JsObject(fields = parent.asJsObject.fields + (name -> res))
+      for (updatedValue <- f(retr(parent)))
+        // asJsObject is already guarded by getField above, FIXME: is it really?
+        yield JsObject(fields = parent.asJsObject.fields + (name -> updatedValue))
 
-    def retr: JsValue => SafeJsValue = v =>
-      getField(v)
-
-    def getField(v: JsValue): SafeJsValue = asObj(v) flatMap {
-      o =>
-        o.fields.get(name).getOrError("Expected field '%s' in '%s'" format(name, v))
+    def retr: JsValue => SafeJsValue = v => asObj(v) flatMap {
+      _.fields.get(name).getOrError("Expected field '%s' in '%s'" format(name, v))
     }
 
     def asObj(v: JsValue): Validated[JsObject] = v match {
-      case o: JsObject =>
-        Right(o)
-      case e@_ =>
-        unexpected("Not a json object: " + e)
+      case o: JsObject => Right(o)
+      case e@_         => unexpected("Not a json object: " + e)
     }
   }
 
diff --git a/src/main/scala/cc/spray/json/lenses/UpdateLens.scala b/src/main/scala/cc/spray/json/lenses/UpdateLens.scala
index c532b15..79c8ed2 100644
--- a/src/main/scala/cc/spray/json/lenses/UpdateLens.scala
+++ b/src/main/scala/cc/spray/json/lenses/UpdateLens.scala
@@ -1,8 +1,7 @@
 package cc.spray.json
 package lenses
 
-trait Update extends (JsValue => JsValue) {
-  outer =>
+trait Update extends (JsValue => JsValue) { outer =>
   def apply(value: JsValue): JsValue
 
   def &&(next: Update): Update = new Update {