API improvements and better examples

5 files changed, 140 insertions, 127 deletions

diff --git a/examples/src/main/scala/decode.scala b/examples/src/main/scala/decode.scala
new file mode 100644
index 0000000..1cc8a12
--- /dev/null
+++ b/examples/src/main/scala/decode.scala
@@ -0,0 +1,65 @@
+package magnolia.examples
+
+import scala.language.existentials
+import scala.language.higherKinds
+
+import magnolia._
+import scala.language.experimental.macros
+
+trait Decoder[T] { def decode(str: String): T }
+
+object Decoder {
+  
+  implicit val string: Decoder[String] = new Decoder[String] { def decode(str: String): String = str }
+  implicit val int: Decoder[Int] = new Decoder[Int] { def decode(str: String): Int = str.toInt }
+  implicit def generic[T]: Decoder[T] = macro Magnolia.generic[T]
+
+  type Typeclass[T] = Decoder[T]
+  
+  def join[T](ctx: JoinContext[Decoder, T]): Decoder[T] = new Decoder[T] {
+    def decode(value: String) = {
+      val (name, values) = parse(value)
+      ctx.construct { param => param.typeclass.decode(values(param.label)) }
+    }
+  }
+
+  def dispatch[T](ctx: DispatchContext[Decoder, T]): Decoder[T] = new Decoder[T] {
+    def decode(param: String) = {
+      val (name, values) = parse(param)
+      val subtype = ctx.subtypes.find(_.label == name).get
+      subtype.typeclass.decode(param)
+    }
+  }
+
+  private def parse(value: String): (String, Map[String, String]) = {
+    val end = value.indexOf('(')
+    val name = value.substring(0, end)
+    
+    def parts(value: String, idx: Int = 0, depth: Int = 0, collected: List[String] = List("")): List[String] = {
+      def plus(char: Char): List[String] = collected.head+char :: collected.tail
+      
+      if(idx == value.length) collected
+      else value(idx) match {
+        case '(' =>
+          parts(value, idx + 1, depth + 1, plus('('))
+        case ')' =>
+          if(depth == 1) plus(')')
+          else parts(value, idx + 1, depth - 1, plus(')'))
+        case ',' =>
+          if(depth == 0) parts(value, idx + 1, depth, "" :: collected)
+          else parts(value, idx + 1, depth, plus(','))
+        case char =>
+          parts(value, idx + 1, depth, plus(char))
+      }
+    }
+    
+    def keyValue(str: String): (String, String) = {
+      val List(label, value) = str.split("=", 2).to[List]
+      (label, value)
+    }
+
+    (name, parts(value.substring(end + 1, value.length - 1)).map(keyValue).toMap)
+  }
+
+}
+
diff --git a/examples/src/main/scala/default.scala b/examples/src/main/scala/default.scala
new file mode 100644
index 0000000..1f602f9
--- /dev/null
+++ b/examples/src/main/scala/default.scala
@@ -0,0 +1,24 @@
+package magnolia.examples
+
+import scala.language.existentials
+import scala.language.higherKinds
+
+import magnolia._
+import scala.language.experimental.macros
+
+trait Default[T] { def default: T }
+
+object Default {
+  type Typeclass[T] = Default[T]
+  def join[T](ctx: JoinContext[Default, T]): Default[T] = new Default[T] {
+    def default = ctx.construct { param => param.typeclass.default }
+  }
+
+  def dispatch[T](ctx: DispatchContext[Default, T])(): Default[T] = new Default[T] {
+    def default: T = ctx.subtypes.head.typeclass.default
+  }
+
+  implicit val string: Default[String] = new Default[String] { def default = "" }
+  implicit val int: Default[Int] = new Default[Int] { def default = 0 }
+  implicit def generic[T]: Default[T] = macro Magnolia.generic[T]
+}
diff --git a/examples/src/main/scala/eq.scala b/examples/src/main/scala/eq.scala
new file mode 100644
index 0000000..ec9be14
--- /dev/null
+++ b/examples/src/main/scala/eq.scala
@@ -0,0 +1,25 @@
+package magnolia.examples
+
+import scala.language.higherKinds
+
+import magnolia._
+import scala.language.experimental.macros
+
+trait Eq[T] { def equal(value: T, value2: T): Boolean }
+
+object Eq {
+  type Typeclass[T] = Eq[T]
+  def join[T](ctx: JoinContext[Eq, T]): Eq[T] = new Eq[T] {
+    def equal(value1: T, value2: T) =
+      ctx.parameters.forall { param => param.typeclass.equal(param.dereference(value1), param.dereference(value2)) }
+  }
+
+  def dispatch[T](ctx: DispatchContext[Eq, T]): Eq[T] = new Eq[T] {
+    def equal(value1: T, value2: T): Boolean =
+      ctx.dispatch(value1) { case sub => sub.typeclass.equal(sub.cast(value1), sub.cast(value2)) }
+  }
+
+  implicit val string: Eq[String] = new Eq[String] { def equal(v1: String, v2: String) = v1 == v2 }
+  implicit val int: Eq[Int] = new Eq[Int] { def equal(v1: Int, v2: Int) = v1 == v2 }
+  implicit def generic[T]: Eq[T] = macro Magnolia.generic[T]
+}
diff --git a/examples/src/main/scala/show.scala b/examples/src/main/scala/show.scala
new file mode 100644
index 0000000..9af828e
--- /dev/null
+++ b/examples/src/main/scala/show.scala
@@ -0,0 +1,26 @@
+package magnolia.examples
+
+import scala.language.existentials
+import scala.language.higherKinds
+
+import magnolia._
+import scala.language.experimental.macros
+
+trait Show[Out, T] { def show(value: T): Out }
+
+object Show {
+  type Typeclass[T] = Show[String, T]
+  def join[T](ctx: JoinContext[Typeclass, T]): Show[String, T] = new Show[String, T] {
+    def show(value: T) = ctx.parameters.map { param =>
+      s"${param.label}=${param.typeclass.show(param.dereference(value))}"
+    }.mkString(s"${ctx.typeName.split("\\.").last}(", ",", ")")
+  }
+
+  def dispatch[T](ctx: DispatchContext[Typeclass, T]): Show[String, T] = new Show[String, T] {
+    def show(value: T): String = ctx.dispatch(value) { sub => sub.typeclass.show(sub.cast(value)) }
+  }
+
+  implicit val string: Show[String, String] = new Show[String, String] { def show(s: String): String = s }
+  implicit val int: Show[String, Int] = new Show[String, Int] { def show(s: Int): String = s.toString }
+  implicit def generic[T]: Show[String, T] = macro Magnolia.generic[T]
+}
diff --git a/examples/src/main/scala/typeclasses.scala b/examples/src/main/scala/typeclasses.scala
deleted file mode 100644
index aaa74fd..0000000
--- a/examples/src/main/scala/typeclasses.scala
+++ /dev/null
@@ -1,127 +0,0 @@
-package magnolia.examples
-
-import scala.collection.immutable.ListMap
-import scala.language.existentials
-import scala.language.higherKinds
-
-import magnolia._
-import scala.reflect._
-import scala.reflect.macros._
-import scala.language.experimental.macros
-import scala.annotation.unchecked.uncheckedVariance
-
-
-object Show {
-  type Typeclass[T] = Show[String, T]
-  def join[T](context: JoinContext[Typeclass, T]): Show[String, T] = new Show[String, T] {
-    def show(value: T) = context.parameters.map { param =>
-      s"${param.label}=${param.typeclass.show(param.dereference(value))}"
-    }.mkString(s"${context.typeName.split("\\.").last}(", ",", ")")
-  }
-
-  def dispatch[T](subclasses: Seq[Subclass[Typeclass, T]])(value: T): String =
-    subclasses.map { sub => sub.cast.andThen { value =>
-      sub.typeclass.show(sub.cast(value))
-    } }.reduce(_ orElse _)(value)
-
-  implicit val string: Show[String, String] = identity
-  implicit val int: Show[String, Int] = new Show[String, Int] { def show(s: Int): String = s.toString }
-  implicit def generic[T]: Show[String, T] = macro Magnolia.generic[T]
-}
-
-trait Show[Out, T] { def show(value: T): Out }
-
-object Eq {
-  type Typeclass[T] = Eq[T]
-  def join[T](context: JoinContext[Eq, T]): Eq[T] = new Eq[T] {
-    def equal(value1: T, value2: T) =
-      context.parameters.forall { param => param.typeclass.equal(param.dereference(value1), param.dereference(value2)) }
-  }
-
-  def dispatch[T](subclasses: Seq[Subclass[Eq, T]]): Eq[T] = new Eq[T] {
-    def equal(value1: T, value2: T) =
-      subclasses.map { case subclass =>
-        subclass.cast.andThen { value => subclass.typeclass.equal(subclass.cast(value1), subclass.cast(value2)) }
-      }.reduce(_ orElse _)(value1)
-  }
-
-  implicit val string: Eq[String] = _ == _
-  implicit val int: Eq[Int] = _ == _
-  implicit def generic[T]: Eq[T] = macro Magnolia.generic[T]
-}
-
-trait Eq[T] { def equal(value: T, value2: T): Boolean }
-
-object Default {
-  type Typeclass[T] = Default[T]
-  def join[T](context: JoinContext[Default, T]): Default[T] = new Default[T] {
-    def default = context.construct { param => param.typeclass.default }
-  }
-
-  def dispatch[T](subclasses: Seq[Subclass[Default, T]])(): Default[T] = new Default[T] {
-    def default = subclasses.head.typeclass.default
-  }
-
-  implicit val string: Default[String] = new Default[String] { def default = "" }
-  implicit val int: Default[Int] = new Default[Int] { def default = 0 }
-  implicit def generic[T]: Default[T] = macro Magnolia.generic[T]
-}
-
-trait Default[T] { def default: T }
-
-object Decoder {
-  def join[T](context: JoinContext[Decoder, T])(value: String): T =
-    context.construct { param => param.typeclass.decode(value) }
-
-  def dispatch[T](subclasses: Seq[Subclass[Decoder, T]])(param: String): T =
-    subclasses.map { subclass =>
-      { case _ if decodes(subclass.typeclass, param) => subclass.typeclass.decode(param) }: PartialFunction[String, T]
-    }.reduce(_ orElse _)(param)
-
-  def decodes[T](tc: Decoder[T], s: String): Boolean = try { tc.decode(s); true } catch { case e: Exception => false }
-  
-  implicit val string: Decoder[String] = new Decoder[String] { def decode(str: String): String = str }
-  implicit val int: Decoder[Int] = new Decoder[Int] { def decode(str: String): Int = str.toInt }
-  implicit def generic[T]: Decoder[T] = macro Magnolia.generic[T]
-}
-
-trait Decoder[T] { def decode(str: String): T }
-
-sealed trait Tree[+T]
-case class Leaf[+L](value: L) extends Tree[L]
-case class Branch[+B](left: Tree[B], right: Tree[B]) extends Tree[B]
-
-sealed trait Entity
-
-case class Company(name: String) extends Entity
-case class Person(name: String, age: Int) extends Entity
-case class Address(line1: String, occupant: Person)
-
-
-
-sealed trait Alphabet
-
-case class Greek(άλφα: Letter, βήτα: Letter, γάμα: Letter, δέλτα: Letter, έψιλον: Letter, ζήτα: Letter, ήτα: Letter, θήτα: Letter) extends Alphabet
-case class Cyrillic(б: Letter, в: Letter, г: Letter, д: Letter, ж: Letter, з: Letter) extends Alphabet
-case class Latin(a: Letter, b: Letter, c: Letter, d: Letter, e: Letter, f: Letter, g: Letter, h: Letter, i: Letter, j: Letter, k: Letter, l: Letter, m: Letter) extends Alphabet
-
-case class Letter(name: String, phonetic: String)
-case class Country(name: String, language: Language, leader: Person)
-case class Language(name: String, code: String, alphabet: Alphabet)
-//case class Person(name: String, dateOfBirth: Date)
-case class Date(year: Int, month: Month, day: Int)
-
-sealed trait Month
-case object Jan extends Month
-case object Feb extends Month
-case object Mar extends Month
-case object Apr extends Month
-case object May extends Month
-case object Jun extends Month
-case object Jul extends Month
-case object Aug extends Month
-case object Sep extends Month
-case object Oct extends Month
-case object Nov extends Month
-case object Dec extends Month
-