Remove the Derivation macro (pureconfig#979)

* Remove the `Derivation` macro * Adapt FAQ to describe how to use splain * Reintroduce blank lines in example's documentation
scala-steward · Mar 21, 2021 · f42bdae · f42bdae
1 parent f352db1
commit f42bdae
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Showing 35 changed files with 197 additions and 732 deletions.
diff --git a/build.sbt b/build.sbt
@@ -9,10 +9,6 @@ organization in ThisBuild := "com.github.pureconfig"
 lazy val core = (project in file("core"))
   .enablePlugins(BoilerplatePlugin, SbtOsgi)
   .settings(commonSettings)
-  .dependsOn(macros)
-
-lazy val macros = (project in file("macros"))
-  .settings(commonSettings)
 
 lazy val testkit = (project in file("testkit"))
   .settings(commonSettings)
@@ -89,7 +85,6 @@ lazy val commonSettings = Seq(
   scalacOptions ++= lintFlags.value,
 
   scalacOptions in Test ~= { _.filterNot(_.contains("-Ywarn-unused")) },
-  scalacOptions in Test += "-Xmacro-settings:materialize-derivations",
 
   scalacOptions in (Compile, console) --= Seq("-Xfatal-warnings", "-Ywarn-unused-import", "-Ywarn-unused:_,-implicits"),
   scalacOptions in (Test, console) := (scalacOptions in (Compile, console)).value,

diff --git a/core/src/main/scala/pureconfig/CollectionReaders.scala b/core/src/main/scala/pureconfig/CollectionReaders.scala
@@ -15,39 +15,39 @@ trait ReadsMissingKeys { this: ConfigReader[_] => }
   */
 trait CollectionReaders {
 
-  implicit def optionReader[A](implicit conv: Derivation[ConfigReader[A]]): ConfigReader[Option[A]] =
+  implicit def optionReader[A](implicit conv: ConfigReader[A]): ConfigReader[Option[A]] =
     new ConfigReader[Option[A]] with ReadsMissingKeys {
       override def from(cur: ConfigCursor): ConfigReader.Result[Option[A]] = {
         if (cur.isUndefined || cur.isNull) Right(None)
-        else conv.value.from(cur).map(Some(_))
+        else conv.from(cur).map(Some(_))
       }
     }
 
   implicit def traversableReader[A, F[A] <: TraversableOnce[A]](implicit
-      configConvert: Derivation[ConfigReader[A]],
+      configConvert: ConfigReader[A],
       cbf: FactoryCompat[A, F[A]]
   ): ConfigReader[F[A]] =
     new ConfigReader[F[A]] {
 
       override def from(cur: ConfigCursor): ConfigReader.Result[F[A]] = {
-        cur.fluent.mapList { valueCur => configConvert.value.from(valueCur) }.map { coll =>
+        cur.fluent.mapList { valueCur => configConvert.from(valueCur) }.map { coll =>
           val builder = cbf.newBuilder()
           (builder ++= coll).result()
         }
       }
     }
 
-  implicit def mapReader[A](implicit reader: Derivation[ConfigReader[A]]): ConfigReader[Map[String, A]] =
+  implicit def mapReader[A](implicit reader: ConfigReader[A]): ConfigReader[Map[String, A]] =
     new ConfigReader[Map[String, A]] {
       override def from(cur: ConfigCursor): ConfigReader.Result[Map[String, A]] = {
-        cur.fluent.mapObject { valueCur => reader.value.from(valueCur) }
+        cur.fluent.mapObject { valueCur => reader.from(valueCur) }
       }
     }
 
-  implicit def arrayReader[A: ClassTag](implicit reader: Derivation[ConfigReader[A]]): ConfigReader[Array[A]] =
+  implicit def arrayReader[A: ClassTag](implicit reader: ConfigReader[A]): ConfigReader[Array[A]] =
     new ConfigReader[Array[A]] {
       override def from(cur: ConfigCursor): ConfigReader.Result[Array[A]] =
-        cur.fluent.mapList(reader.value.from).map(_.toArray)
+        cur.fluent.mapList(reader.from).map(_.toArray)
     }
 }
 

diff --git a/core/src/main/scala/pureconfig/CollectionWriters.scala b/core/src/main/scala/pureconfig/CollectionWriters.scala
@@ -18,38 +18,38 @@ trait WritesMissingKeys[A] { this: ConfigWriter[A] =>
   */
 trait CollectionWriters {
 
-  implicit def optionWriter[A](implicit conv: Derivation[ConfigWriter[A]]): ConfigWriter[Option[A]] =
+  implicit def optionWriter[A](implicit conv: ConfigWriter[A]): ConfigWriter[Option[A]] =
     new ConfigWriter[Option[A]] with WritesMissingKeys[Option[A]] {
       override def to(t: Option[A]): ConfigValue =
         t match {
-          case Some(v) => conv.value.to(v)
+          case Some(v) => conv.to(v)
           case None => ConfigValueFactory.fromAnyRef(null)
         }
 
-      def toOpt(t: Option[A]): Option[ConfigValue] = t.map(conv.value.to)
+      def toOpt(t: Option[A]): Option[ConfigValue] = t.map(conv.to)
     }
 
   implicit def traversableWriter[A, F[A] <: TraversableOnce[A]](implicit
-      configConvert: Derivation[ConfigWriter[A]]
+      configConvert: ConfigWriter[A]
   ): ConfigWriter[F[A]] =
     new ConfigWriter[F[A]] {
 
       override def to(ts: F[A]): ConfigValue = {
-        ConfigValueFactory.fromIterable(ts.toList.map(configConvert.value.to).asJava)
+        ConfigValueFactory.fromIterable(ts.toList.map(configConvert.to).asJava)
       }
     }
 
-  implicit def mapWriter[A](implicit configConvert: Derivation[ConfigWriter[A]]): ConfigWriter[Map[String, A]] =
+  implicit def mapWriter[A](implicit configConvert: ConfigWriter[A]): ConfigWriter[Map[String, A]] =
     new ConfigWriter[Map[String, A]] {
       override def to(keyVals: Map[String, A]): ConfigValue = {
-        ConfigValueFactory.fromMap(keyVals.mapValues(configConvert.value.to).toMap.asJava)
+        ConfigValueFactory.fromMap(keyVals.mapValues(configConvert.to).toMap.asJava)
       }
     }
 
-  implicit def arrayWriter[A](implicit writer: Derivation[ConfigWriter[A]]): ConfigWriter[Array[A]] =
+  implicit def arrayWriter[A](implicit writer: ConfigWriter[A]): ConfigWriter[Array[A]] =
     new ConfigWriter[Array[A]] {
       override def to(a: Array[A]): ConfigValue =
-        ConfigValueFactory.fromIterable(a.toList.map(writer.value.to).asJava)
+        ConfigValueFactory.fromIterable(a.toList.map(writer.to).asJava)
     }
 }
 

diff --git a/core/src/main/scala/pureconfig/ConfigConvert.scala b/core/src/main/scala/pureconfig/ConfigConvert.scala
@@ -42,7 +42,7 @@ trait ConfigConvert[A] extends ConfigReader[A] with ConfigWriter[A] { outer =>
   */
 object ConfigConvert extends ConvertHelpers {
 
-  def apply[A](implicit conv: Derivation[ConfigConvert[A]]): ConfigConvert[A] = conv.value
+  def apply[A](implicit conv: ConfigConvert[A]): ConfigConvert[A] = conv
 
   def apply[A](reader: ConfigReader[A], writer: ConfigWriter[A]): ConfigConvert[A] =
     new ConfigConvert[A] {
@@ -51,10 +51,10 @@ object ConfigConvert extends ConvertHelpers {
     }
 
   implicit def fromReaderAndWriter[A](implicit
-      reader: Derivation[ConfigReader[A]],
-      writer: Derivation[ConfigWriter[A]]
+      reader: ConfigReader[A],
+      writer: ConfigWriter[A]
   ): ConfigConvert[A] =
-    ConfigConvert(reader.value, writer.value)
+    ConfigConvert(reader, writer)
 
   def viaString[A](fromF: String => Either[FailureReason, A], toF: A => String): ConfigConvert[A] =
     ConfigConvert(ConfigReader.fromString(fromF), ConfigWriter.toString(toF))

diff --git a/core/src/main/scala/pureconfig/ConfigReader.scala b/core/src/main/scala/pureconfig/ConfigReader.scala
@@ -151,7 +151,7 @@ object ConfigReader extends BasicReaders with CollectionReaders with ProductRead
     def fail[A](failure: ConfigReaderFailure): ConfigReader.Result[A] = Left(ConfigReaderFailures(failure))
   }
 
-  def apply[A](implicit reader: Derivation[ConfigReader[A]]): ConfigReader[A] = reader.value
+  def apply[A](implicit reader: ConfigReader[A]): ConfigReader[A] = reader
 
   /** Creates a `ConfigReader` from a function reading a `ConfigCursor`.
     *

diff --git a/core/src/main/scala/pureconfig/ConfigSource.scala b/core/src/main/scala/pureconfig/ConfigSource.scala
@@ -57,8 +57,7 @@ trait ConfigSource {
     * @return A `Right` with the configuration if it is possible to create an instance of type
     *         `A` from this source, a `Failure` with details on why it isn't possible otherwise
     */
-  final def load[A](implicit reader: Derivation[ConfigReader[A]]): Result[A] =
-    cursor().flatMap(reader.value.from)
+  final def load[A](implicit reader: ConfigReader[A]): Result[A] = cursor().flatMap(reader.from)
 
   /** Loads a configuration of type `A` from this source. If it is not possible to create an
     * instance of `A`, this method throws a `ConfigReaderException`.
@@ -67,7 +66,7 @@ trait ConfigSource {
     * @return The configuration of type `A` loaded from this source.
     */
   @throws[ConfigReaderException[_]]
-  final def loadOrThrow[A: ClassTag](implicit reader: Derivation[ConfigReader[A]]): A = {
+  final def loadOrThrow[A: ClassTag](implicit reader: ConfigReader[A]): A = {
     load[A] match {
       case Right(config) => config
       case Left(failures) => throw new ConfigReaderException[A](failures)

diff --git a/core/src/main/scala/pureconfig/ConfigWriter.scala b/core/src/main/scala/pureconfig/ConfigWriter.scala
@@ -38,7 +38,7 @@ trait ConfigWriter[A] {
   */
 object ConfigWriter extends BasicWriters with CollectionWriters with ProductWriters with ExportedWriters {
 
-  def apply[A](implicit writer: Derivation[ConfigWriter[A]]): ConfigWriter[A] = writer.value
+  def apply[A](implicit writer: ConfigWriter[A]): ConfigWriter[A] = writer
 
   /** Creates a `ConfigWriter` from a function.
     *

diff --git a/core/src/main/scala/pureconfig/configurable/package.scala b/core/src/main/scala/pureconfig/configurable/package.scala
@@ -50,12 +50,12 @@ package object configurable {
 
   def genericMapReader[K, V](
       keyParser: String => Either[FailureReason, K]
-  )(implicit readerV: Derivation[ConfigReader[V]]): ConfigReader[Map[K, V]] =
+  )(implicit readerV: ConfigReader[V]): ConfigReader[Map[K, V]] =
     ConfigReader.fromCursor { cursor =>
       cursor.asMap.flatMap { map =>
         map.foldLeft[ConfigReader.Result[Map[K, V]]](Right(Map.empty)) { case (acc, (key, valueCursor)) =>
           val eitherKeyOrError = cursor.scopeFailure(keyParser(key))
-          val eitherValueOrError = readerV.value.from(valueCursor)
+          val eitherValueOrError = readerV.from(valueCursor)
           ConfigReader.Result.zipWith(acc, ConfigReader.Result.zipWith(eitherKeyOrError, eitherValueOrError)(_ -> _))(
             _ + _
           )
@@ -65,10 +65,10 @@ package object configurable {
 
   def genericMapWriter[K, V](
       keyFormatter: K => String
-  )(implicit writerV: Derivation[ConfigWriter[V]]): ConfigWriter[Map[K, V]] =
+  )(implicit writerV: ConfigWriter[V]): ConfigWriter[Map[K, V]] =
     ConfigWriter.fromFunction[Map[K, V]](map =>
       ConfigValueFactory.fromMap(map.map { case (key, value) =>
-        keyFormatter(key) -> writerV.value.to(value)
+        keyFormatter(key) -> writerV.to(value)
       }.asJava)
     )
 }
diff --git a/core/src/main/scala/pureconfig/package.scala b/core/src/main/scala/pureconfig/package.scala
@@ -22,7 +22,7 @@ package object pureconfig {
     *         isn't possible
     */
   @deprecated("Use `ConfigSource.default.load[A]` instead", "0.12.0")
-  def loadConfig[A](implicit reader: Derivation[ConfigReader[A]]): ConfigReader.Result[A] =
+  def loadConfig[A](implicit reader: ConfigReader[A]): ConfigReader.Result[A] =
     ConfigSource.default.load[A]
 
   /** Load a configuration of type `A` from the standard configuration files
@@ -33,7 +33,7 @@ package object pureconfig {
     *         isn't possible
     */
   @deprecated("Use `ConfigSource.default.at(namespace).load[A]` instead", "0.12.0")
-  def loadConfig[A](namespace: String)(implicit reader: Derivation[ConfigReader[A]]): ConfigReader.Result[A] =
+  def loadConfig[A](namespace: String)(implicit reader: ConfigReader[A]): ConfigReader.Result[A] =
     ConfigSource.default.at(namespace).load[A]
 
   /** Load a configuration of type `A` from the given file. Note that standard configuration
@@ -44,7 +44,7 @@ package object pureconfig {
     *         isn't possible
     */
   @deprecated("Use `ConfigSource.default(ConfigSource.file(path)).load[A]` instead", "0.12.0")
-  def loadConfig[A](path: Path)(implicit reader: Derivation[ConfigReader[A]]): ConfigReader.Result[A] =
+  def loadConfig[A](path: Path)(implicit reader: ConfigReader[A]): ConfigReader.Result[A] =
     ConfigSource.default(ConfigSource.file(path)).load[A]
 
   /** Load a configuration of type `A` from the given file. Note that standard configuration
@@ -56,21 +56,17 @@ package object pureconfig {
     *         isn't possible
     */
   @deprecated("Use `ConfigSource.default(ConfigSource.file(path)).at(namespace).load[A]` instead", "0.12.0")
-  def loadConfig[A](path: Path, namespace: String)(implicit
-      reader: Derivation[ConfigReader[A]]
-  ): ConfigReader.Result[A] =
+  def loadConfig[A](path: Path, namespace: String)(implicit reader: ConfigReader[A]): ConfigReader.Result[A] =
     ConfigSource.default(ConfigSource.file(path)).at(namespace).load[A]
 
   /** Load a configuration of type `A` from the given `Config` */
   @deprecated("Use `ConfigSource.fromConfig(conf).load[A]` instead", "0.12.0")
-  def loadConfig[A](conf: Config)(implicit reader: Derivation[ConfigReader[A]]): ConfigReader.Result[A] =
+  def loadConfig[A](conf: Config)(implicit reader: ConfigReader[A]): ConfigReader.Result[A] =
     ConfigSource.fromConfig(conf).load[A]
 
   /** Load a configuration of type `A` from the given `Config` */
   @deprecated("Use `ConfigSource.fromConfig(conf).at(namespace).load[A]` instead", "0.12.0")
-  def loadConfig[A](conf: Config, namespace: String)(implicit
-      reader: Derivation[ConfigReader[A]]
-  ): ConfigReader.Result[A] =
+  def loadConfig[A](conf: Config, namespace: String)(implicit reader: ConfigReader[A]): ConfigReader.Result[A] =
     ConfigSource.fromConfig(conf).at(namespace).load[A]
 
   /** Load a configuration of type `A` from the given `Config`, falling back to the default configuration
@@ -81,7 +77,7 @@ package object pureconfig {
     *         isn't possible
     */
   @deprecated("Use `ConfigSource.fromConfig(conf).withFallback(ConfigSource.default).load[A]` instead", "0.12.0")
-  def loadConfigWithFallback[A](conf: Config)(implicit reader: Derivation[ConfigReader[A]]): ConfigReader.Result[A] =
+  def loadConfigWithFallback[A](conf: Config)(implicit reader: ConfigReader[A]): ConfigReader.Result[A] =
     ConfigSource.fromConfig(conf).withFallback(ConfigSource.default).load[A]
 
   /** Load a configuration of type `A` from the given `Config`, falling back to the default configuration
@@ -97,7 +93,7 @@ package object pureconfig {
     "0.12.0"
   )
   def loadConfigWithFallback[A](conf: Config, namespace: String)(implicit
-      reader: Derivation[ConfigReader[A]]
+      reader: ConfigReader[A]
   ): ConfigReader.Result[A] =
     ConfigSource.fromConfig(conf).withFallback(ConfigSource.default).at(namespace).load[A]
 
@@ -107,8 +103,7 @@ package object pureconfig {
     */
   @throws[ConfigReaderException[_]]
   @deprecated("Use `ConfigSource.default.loadOrThrow[A]` instead", "0.12.0")
-  def loadConfigOrThrow[A: ClassTag](implicit reader: Derivation[ConfigReader[A]]): A =
-    ConfigSource.default.loadOrThrow[A]
+  def loadConfigOrThrow[A: ClassTag](implicit reader: ConfigReader[A]): A = ConfigSource.default.loadOrThrow[A]
 
   /** Load a configuration of type `A` from the standard configuration files
     *
@@ -117,7 +112,7 @@ package object pureconfig {
     */
   @throws[ConfigReaderException[_]]
   @deprecated("Use `ConfigSource.default.at(namespace).loadOrThrow[A]` instead", "0.12.0")
-  def loadConfigOrThrow[A: ClassTag](namespace: String)(implicit reader: Derivation[ConfigReader[A]]): A =
+  def loadConfigOrThrow[A: ClassTag](namespace: String)(implicit reader: ConfigReader[A]): A =
     ConfigSource.default.at(namespace).loadOrThrow[A]
 
   /** Load a configuration of type `A` from the given file. Note that standard configuration
@@ -127,7 +122,7 @@ package object pureconfig {
     */
   @throws[ConfigReaderException[_]]
   @deprecated("Use `ConfigSource.default(ConfigSource.file(path)).loadOrThrow[A]` instead", "0.12.0")
-  def loadConfigOrThrow[A: ClassTag](path: Path)(implicit reader: Derivation[ConfigReader[A]]): A =
+  def loadConfigOrThrow[A: ClassTag](path: Path)(implicit reader: ConfigReader[A]): A =
     ConfigSource.default(ConfigSource.file(path)).loadOrThrow[A]
 
   /** Load a configuration of type `A` from the given file. Note that standard configuration
@@ -138,7 +133,7 @@ package object pureconfig {
     */
   @throws[ConfigReaderException[_]]
   @deprecated("Use `ConfigSource.default(ConfigSource.file(path)).at(namespace).loadOrThrow[A]` instead", "0.12.0")
-  def loadConfigOrThrow[A: ClassTag](path: Path, namespace: String)(implicit reader: Derivation[ConfigReader[A]]): A =
+  def loadConfigOrThrow[A: ClassTag](path: Path, namespace: String)(implicit reader: ConfigReader[A]): A =
     ConfigSource.default(ConfigSource.file(path)).at(namespace).loadOrThrow[A]
 
   /** Load a configuration of type `A` from the given `Config`
@@ -148,7 +143,7 @@ package object pureconfig {
     */
   @throws[ConfigReaderException[_]]
   @deprecated("Use `ConfigSource.fromConfig(conf).loadOrThrow[A]` instead", "0.12.0")
-  def loadConfigOrThrow[A: ClassTag](conf: Config)(implicit reader: Derivation[ConfigReader[A]]): A =
+  def loadConfigOrThrow[A: ClassTag](conf: Config)(implicit reader: ConfigReader[A]): A =
     ConfigSource.fromConfig(conf).loadOrThrow[A]
 
   /** Load a configuration of type `A` from the given `Config`
@@ -159,7 +154,7 @@ package object pureconfig {
     */
   @throws[ConfigReaderException[_]]
   @deprecated("Use `ConfigSource.fromConfig(conf).at(namespace).loadOrThrow[A]` instead", "0.12.0")
-  def loadConfigOrThrow[A: ClassTag](conf: Config, namespace: String)(implicit reader: Derivation[ConfigReader[A]]): A =
+  def loadConfigOrThrow[A: ClassTag](conf: Config, namespace: String)(implicit reader: ConfigReader[A]): A =
     ConfigSource.fromConfig(conf).at(namespace).loadOrThrow[A]
 
   /** Load a configuration of type `A` from the given `Config`, falling back to the default configuration
@@ -169,7 +164,7 @@ package object pureconfig {
     */
   @throws[ConfigReaderException[_]]
   @deprecated("Use `ConfigSource.fromConfig(conf).withFallback(ConfigSource.default).loadOrThrow[A]` instead", "0.12.0")
-  def loadConfigWithFallbackOrThrow[A: ClassTag](conf: Config)(implicit reader: Derivation[ConfigReader[A]]): A =
+  def loadConfigWithFallbackOrThrow[A: ClassTag](conf: Config)(implicit reader: ConfigReader[A]): A =
     ConfigSource.fromConfig(conf).withFallback(ConfigSource.default).loadOrThrow[A]
 
   /** Load a configuration of type `A` from the given `Config`, falling back to the default configuration
@@ -183,9 +178,7 @@ package object pureconfig {
     "Use `ConfigSource.fromConfig(conf).withFallback(ConfigSource.default).at(namespace).loadOrThrow[A]` instead",
     "0.12.0"
   )
-  def loadConfigWithFallbackOrThrow[A: ClassTag](conf: Config, namespace: String)(implicit
-      reader: Derivation[ConfigReader[A]]
-  ): A =
+  def loadConfigWithFallbackOrThrow[A: ClassTag](conf: Config, namespace: String)(implicit reader: ConfigReader[A]): A =
     ConfigSource.fromConfig(conf).withFallback(ConfigSource.default).at(namespace).loadOrThrow[A]
 
   /** Save the given configuration into a property file
@@ -201,7 +194,7 @@ package object pureconfig {
       outputPath: Path,
       overrideOutputPath: Boolean = false,
       options: ConfigRenderOptions = ConfigRenderOptions.defaults()
-  )(implicit writer: Derivation[ConfigWriter[A]]): Unit = {
+  )(implicit writer: ConfigWriter[A]): Unit = {
 
     if (!overrideOutputPath && Files.isRegularFile(outputPath)) {
       throw new IllegalArgumentException(s"Cannot save configuration in file '$outputPath' because it already exists")
@@ -225,12 +218,12 @@ package object pureconfig {
       conf: A,
       outputStream: OutputStream,
       options: ConfigRenderOptions = ConfigRenderOptions.defaults()
-  )(implicit writer: Derivation[ConfigWriter[A]]): Unit = {
+  )(implicit writer: ConfigWriter[A]): Unit = {
 
     // HOCON requires UTF-8:
     // https://github.com/lightbend/config/blob/master/HOCON.md#unchanged-from-json
     val printOutputStream = new OutputStreamWriter(outputStream, UTF_8)
-    val rawConf = writer.value.to(conf)
+    val rawConf = writer.to(conf)
     printOutputStream.write(rawConf.render(options))
     printOutputStream.close()
   }
@@ -250,7 +243,7 @@ package object pureconfig {
     */
   @deprecated("Construct a custom `ConfigSource` pipeline instead", "0.12.0")
   def loadConfigFromFiles[A](files: Traversable[Path], failOnReadError: Boolean = false, namespace: String = "")(
-      implicit reader: Derivation[ConfigReader[A]]
+      implicit reader: ConfigReader[A]
   ): ConfigReader.Result[A] = {
     ConfigSource
       .default(
@@ -270,7 +263,7 @@ package object pureconfig {
   @deprecated("Construct a custom `ConfigSource` pipeline instead", "0.12.0")
   def loadConfigFromFilesOrThrow[A: ClassTag](
       files: Traversable[Path]
-  )(implicit reader: Derivation[ConfigReader[A]]): A = {
+  )(implicit reader: ConfigReader[A]): A = {
     ConfigSource
       .default(
         files