Merge pull request #879 from seldridge/issue-764-refactor-pr-pointer-optionsPackage

- Adds firrtl.options package and tests
- Does not use firrtl.options in any way

1 files changed, 27 insertions, 0 deletions

diff --git a/src/main/scala/firrtl/options/OptionsView.scala b/src/main/scala/firrtl/options/OptionsView.scala
new file mode 100644
index 00000000..dade5c56
--- /dev/null
+++ b/src/main/scala/firrtl/options/OptionsView.scala
@@ -0,0 +1,27 @@
+// See LICENSE for license details.
+
+package firrtl.options
+
+import firrtl.AnnotationSeq
+
+/** Type class defining a "view" of an [[AnnotationSeq]]
+  * @tparam T the type to which this viewer converts an [[AnnotationSeq]] to
+  */
+trait OptionsView[T] {
+
+  /** Convert an [[AnnotationSeq]] to some other type
+    * @param options some annotations
+    */
+  def view(options: AnnotationSeq): Option[T]
+}
+
+/** A shim to manage multiple "views" of an [[AnnotationSeq]] */
+object Viewer {
+
+  /** Convert annotations to options using an implicitly provided [[OptionsView]]
+    * @param options some annotations
+    * @param optionsView a converter of options to the requested type
+    * @tparam T the type to which the input [[AnnotationSeq]] should be viewed as
+    */
+  def view[T](options: AnnotationSeq)(implicit optionsView: OptionsView[T]): Option[T] = optionsView.view(options)
+}