StripMargin string interpolator macro

Strip.scala

/**
 * This interpolator can be evaluated in compile time, so you can use to generate 
 * constant strings (if all params are also constant)
 * 
 * Works on Scala 2.10.2
 */

implicit class stripInterpolator(sc: StringContext) {
  def strip(params: Any*) = macro stripMacro
}

def stripMacro(c: Context)(params: c.Expr[Any]*): c.Expr[String] = {
  import c.universe._

  val Apply(_, List(Apply(_, rawParts))) = c.prefix.tree

  val parts = rawParts.map(x => {
    val Literal(Constant(res: String)) = x
    res
  })

  val evalParams = params.map(x => {
    c.eval(c.Expr[Any](c.resetAllAttrs(x.tree)))
  })

  val res = StringContext(parts:_*).s(evalParams:_*)

  c.Expr[String](Literal(Constant(res.stripMargin)))

}

// scala> val name = "Foo"
// name: String = Foo
//
// scala> val email = "[email protected]"
// email: String = [email protected]
//
// scala> strip"""|{
//                |  "name" : "$name",
//                |  "email" : "$email"
//                |}"""
//
// res0: String = 
// {
//   "name" : "Foo",
//   "email" : "[email protected]"
// }
//