dotty.tools.dotc.transform.ByNameClosures.scala Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of dotty-compiler_0.17 Show documentation

dotty-compiler-bootstrapped

The newest version!

package dotty.tools.dotc
package transform

import core._
import Contexts._
import Types._
import Flags._
import DenotTransformers.IdentityDenotTransformer
import core.StdNames.nme

/** This phase translates arguments to call-by-name parameters, using the rules
 *
 *      x           ==>    x                  if x is a => parameter
 *      e.apply()   ==>    (e)       if e is pure
 *      e           ==>    (() => e) for all other arguments
 *
 *  where
 *
 *     : [T](() => T): T
 *
 *  is a synthetic method defined in Definitions. Erasure will later strip the  wrappers.
 */
class ByNameClosures extends TransformByNameApply with IdentityDenotTransformer { thisPhase =>
  import ast.tpd._

  override def phaseName: String = ByNameClosures.name

  override def mkByNameClosure(arg: Tree, argType: Type)(implicit ctx: Context): Tree = {
    val meth = ctx.newSymbol(
      ctx.owner, nme.ANON_FUN, Synthetic | Method, MethodType(Nil, Nil, argType))
    Closure(meth, _ => arg.changeOwnerAfter(ctx.owner, meth, thisPhase)).withSpan(arg.span)
  }
}

object ByNameClosures {
  val name: String = "byNameClosures"
}