package sbt import java.io.File import Keys.Classpath import scala.annotation.implicitNotFound object Append { @implicitNotFound(msg = "No implicit for Append.Value[${A}, ${B}] found,\n so ${B} cannot be appended to ${A}") sealed trait Value[A,B] { def appendValue(a: A, b: B): A } @implicitNotFound(msg = "No implicit for Append.Values[${A}, ${B}] found,\n so ${B} cannot be appended to ${A}") sealed trait Values[A,-B] { def appendValues(a: A, b: B): A } sealed trait Sequence[A,-B,T] extends Value[A,T] with Values[A,B] implicit def appendSeq[T, V <: T]: Sequence[Seq[T], Seq[V], V] = new Sequence[Seq[T], Seq[V], V] { def appendValues(a: Seq[T], b: Seq[V]): Seq[T] = a ++ b def appendValue(a: Seq[T], b: V): Seq[T] = a :+ b } implicit def appendString: Value[String, String] = new Value[String, String] { def appendValue(a: String, b: String) = a + b } implicit def appendInt = new Value[Int, Int] { def appendValue(a: Int, b: Int) = a + b } implicit def appendLong = new Value[Long, Long] { def appendValue(a: Long, b: Long) = a + b } implicit def appendDouble = new Value[Double, Double] { def appendValue(a: Double, b: Double) = a + b } implicit def appendClasspath: Sequence[Classpath, Seq[File], File] = new Sequence[Classpath, Seq[File], File] { def appendValues(a: Classpath, b: Seq[File]): Classpath = a ++ Attributed.blankSeq(b) def appendValue(a: Classpath, b: File): Classpath = a :+ Attributed.blank(b) } implicit def appendSet[T, V <: T]: Sequence[Set[T], Set[V], V] = new Sequence[Set[T], Set[V], V] { def appendValues(a: Set[T], b: Set[V]): Set[T] = a ++ b def appendValue(a: Set[T], b: V): Set[T] = a + b } implicit def appendMap[A,B, X <: A, Y <: B]: Sequence[Map[A,B], Map[X,Y], (X,Y)] = new Sequence[Map[A,B], Map[X,Y], (X,Y)] { def appendValues(a: Map[A,B], b: Map[X,Y]): Map[A,B] = a ++ b def appendValue(a: Map[A,B], b: (X,Y)): Map[A,B] = a + b } }