MkExportDefMacro

mkdef.scala

  def mkExportDefMacro(tcTpe: Type, exportTc: Type, nme: TermName): Tree = {
    val tcRef = mkAttributedRef(tcTpe)

    val kind = tcTpe.typeParams.map(_.asType.typeParams.length)
    val suffix =
      if(kind.exists(_ > 1) || kind.size > 22)
          c.abort(c.enclosingPosition, s"$tcTpe has an unsupported kind")
      else kind.mkString("")
    val (f, fd) = {
      val t = TypeName(c.freshName)
      val (ns, nts) = (kind.map { k =>
        val tn = TypeName(c.freshName)
        (tn, if(k == 0) q"type $tn" else q"type $tn[_]")
      }).unzip
      (t, q"""type $t[..$nts] >: $tcRef[..$ns]""")
    }

    val (ts: List[TypeName], tds: List[Tree]) = (kind.map { k =>
      val t = TypeName(c.freshName)
      (t, if(k == 0) q"type $t" else q"type $t[_]")
    }).unzip

    val exportTpt = c.internal.gen.mkAttributedRef(exportTc.typeSymbol)
    val exportsImpl = TermName(s"exportsImpl$suffix")

    q"""
    implicit def $nme[$fd, ..$tds]: $exportTpt[$f[..$ts]] =
      macro _root_.export.ExportsImplExpr.$exportsImpl[$tcRef, ..$ts, $exportTpt]
      """
  }