Add spray compatibility layer

1 files changed, 40 insertions, 0 deletions

diff --git a/yamlesque-spray/src/main/scala/formats.scala b/yamlesque-spray/src/main/scala/formats.scala
new file mode 100644
index 0000000..4434347
--- /dev/null
+++ b/yamlesque-spray/src/main/scala/formats.scala
@@ -0,0 +1,40 @@
+package yamlesque
+
+import spray.json._
+
+trait JsonYamlFormats {
+
+  implicit def jsonToYamlReader[A](implicit jsReader: JsonReader[A]): YamlReader[A] = new YamlReader[A] {
+    override def read(yaml: YamlValue): A = jsReader.read(JsonFormats.yamlToJson(yaml))
+  }
+
+  implicit def jsonToYamlWriter[A](implicit jsWriter: JsonWriter[A]): YamlWriter[A] = new YamlWriter[A] {
+    override def write(a: A): YamlValue = JsonFormats.jsonToYaml(jsWriter.write(a))
+  }
+
+}
+
+object JsonFormats {
+
+  def jsonToYaml(js: JsValue): YamlValue = js match {
+    case JsNull => YamlScalar.Empty
+    case JsNumber(number) => YamlScalar(number.toString)
+    case JsBoolean(value) => YamlScalar(value.toString)
+    case JsString(value) => YamlScalar(value)
+    case JsArray(elements) => YamlSequence(elements.map(jsonToYaml _ ))
+    case JsObject(fields) => YamlMapping(fields.mapValues(jsonToYaml _ ))
+  }
+
+  val JsNumberPattern = """([-+]?[0-9]*\.?[0-9]+(?:[eE][-+]?[0-9]+)?)""".r
+
+  def yamlToJson(yaml: YamlValue): JsValue = yaml match {
+    case YamlScalar.Empty => JsNull
+    case YamlScalar("true") => JsTrue
+    case YamlScalar("false") => JsFalse
+    case YamlScalar(JsNumberPattern(x)) => JsNumber(x.toDouble)
+    case YamlScalar(x) => JsString(x)
+    case YamlSequence(elements) => JsArray(elements.map(yamlToJson))
+    case YamlMapping(fields) => JsObject(fields.mapValues(yamlToJson))
+  }
+
+}