Function definitions with Decorators

build.sbt

@@ -13,7 +13,7 @@ startYear                 := Some(2018)
 licenses += ("Apache-2.0", new URL("https://www.apache.org/licenses/LICENSE-2.0.txt"))
 //headerLicense := Some(License.ALv2("2018", organizationName.value))
 resolvers += Resolver.bintrayRepo("fluencelabs", "releases")
-//scalafmtOnCompile := true,
+scalafmtOnCompile := true
 // see good explanation https://gist.github.com/djspiewak/7a81a395c461fd3a09a6941d4cd040f2
 scalacOptions += "-Ypartial-unification"
 

src/main/scala/fluence/hackethberlin/Decorator.scala

@@ -0,0 +1,11 @@
+package fluence.hackethberlin
+
+sealed abstract class Decorator(name: String) {
+  def toVyper: String = s"@$name"
+}
+
+object Decorator {
+  case object `@public` extends Decorator("public")
+  case object `@payable` extends Decorator("payable")
+  case object `@constant` extends Decorator("constant")
+}

src/main/scala/fluence/hackethberlin/FuncDef.scala

@@ -0,0 +1,17 @@
+package fluence.hackethberlin
+
+import fluence.hackethberlin.types.DataVyper
+import shapeless._
+
+class FuncDef[Args <: HList: DataVyper](
+  name: String,
+  argsDef: Args,
+  decorators: Set[Decorator] = Set.empty
+) {
+
+  def toVyper: String =
+    s"${decorators.map(_.toVyper).mkString("\n")}\ndef $name(${DataVyper[Args].mkString(argsDef, ", ")}):\n   body;\n"
+
+  def @:(decorator: Decorator): FuncDef[Args] =
+    new FuncDef[Args](name, argsDef, decorators + decorator)
+}

src/main/scala/fluence/hackethberlin/MakeVyperApp.scala

@@ -2,6 +2,7 @@ package fluence.hackethberlin
 
 import shapeless._
 import types._
+import Decorator._
 
 object MakeVyperApp extends App {
 
@@ -21,6 +22,15 @@ object MakeVyperApp extends App {
       ("struct2" → struct) :: HNil
   )
 
+  val func = new FuncDef(
+    "myFunc",
+    ("address" → address) :: HNil
+  )
+
   println(data.toVyper)
 
+  println(func.toVyper)
+
+  println((`@public` @: func).toVyper)
+
 }

src/main/scala/fluence/hackethberlin/types/DataVyper.scala

@@ -5,6 +5,9 @@ import shapeless.tag._
 
 sealed trait DataVyper[T] {
   def toVyperDefinitions(data: T): List[String]
+
+  def mkString(data: T, sep: String): String =
+    toVyperDefinitions(data).mkString(sep)
 }
 
 sealed trait LowPriorityDataVyperImplicits {
@@ -30,6 +33,8 @@ sealed trait LowPriorityDataVyperImplicits {
 
 object DataVyper extends LowPriorityDataVyperImplicits {
 
+  def apply[T](implicit dataVyper: DataVyper[T]): DataVyper[T] = dataVyper
+
   implicit def pairDataPublicVyper[T <: Type]: DataVyper[(String, T @@ Public)] =
     new DataVyper[(String, T @@ Public)] {
       override def toVyperDefinitions(pair: (String, T @@ Public)): List[String] = {