scala.reflect.quasiquotes.Quasiquotes.scala Maven / Gradle / Ivy

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Compiler for the SubScript extension of the Scala Programming Language

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package scala.reflect
package quasiquotes

import scala.reflect.macros.runtime.Context

abstract class Quasiquotes extends Parsers
                              with Holes
                              with Placeholders
                              with Reifiers {
  val c: Context
  val global: c.universe.type = c.universe
  import c.universe._

  def debug(msg: => String): Unit =
    if (settings.Yquasiquotedebug.value) println(msg)

  lazy val (universe: Tree, args, parts, parse, reify, method) = c.macroApplication match {
    case Apply(build.SyntacticTypeApplied(Select(Select(Apply(Select(universe0, _), List(Apply(_, parts0))), interpolator0), method0), _), args0) =>
      debug(s"parse prefix:\nuniverse=$universe0\nparts=$parts0\ninterpolator=$interpolator0\nmethod=$method0\nargs=$args0\n")
      val parts1 = parts0.map {
        case lit @ Literal(Constant(s: String)) => s -> lit.pos
        case part => c.abort(part.pos, "Quasiquotes can only be used with literal strings")
      }
      val reify0 = method0 match {
        case nme.apply   => new ApplyReifier().reifyFillingHoles(_)
        case nme.unapply => new UnapplyReifier().reifyFillingHoles(_)
        case other       => global.abort(s"Unknown quasiquote api method: $other")
      }
      val parse0 = interpolator0 match {
        case nme.q       => TermParser.parse(_)
        case nme.tq      => TypeParser.parse(_)
        case nme.cq      => CaseParser.parse(_)
        case nme.pq      => PatternParser.parse(_)
        case nme.fq      => ForEnumeratorParser.parse(_)
        case other       => global.abort(s"Unknown quasiquote flavor: $other")
      }
      (universe0, args0, parts1, parse0, reify0, method0)
    case _ =>
      global.abort(s"Couldn't parse call prefix tree ${c.macroApplication}.")
  }

  lazy val u = universe // shortcut
  lazy val universeTypes = new definitions.UniverseDependentTypes(universe)

  def expandQuasiquote = {
    debug(s"macro application:\n${c.macroApplication}\n")
    debug(s"code to parse:\n$code\n")
    val tree = parse(code)
    debug(s"parsed:\n${showRaw(tree)}\n$tree\n")
    val reified = reify(tree)
    def sreified =
      reified
        .toString
        .replace("scala.reflect.runtime.`package`.universe.internal.reificationSupport.", "")
        .replace("scala.reflect.runtime.`package`.universe.", "")
        .replace("scala.collection.immutable.", "")
    debug(s"reified tree:\n$sreified\n")
    reified
  }
}