1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
|
import scala.reflect.macros.Context
import scala.language.experimental.macros
trait Tree
case object SomeTree extends Tree
object NewQuasiquotes {
implicit class QuasiquoteInterpolation(c: StringContext) {
object nq {
def unapply(t: Tree): Any = macro QuasiquoteMacros.unapplyImpl
}
}
}
object QuasiquoteMacros {
def unapplyImpl(c: Context)(t: c.Expr[Tree]) = {
import c.universe._
import Flag._
// q"""
// new {
// def unapply(t: Tree) = t match {
// case SomeTree => Some((SomeTree, SomeTree))
// case _ => None
// }
// }.unapply($t)
// """
c.Expr[Any](Apply(
Select(
Block(List(
ClassDef(Modifiers(FINAL), newTypeName("$anon"), List(),
Template(List(Select(Ident(newTermName("scala")), newTypeName("AnyRef"))), emptyValDef, List(
DefDef(Modifiers(), nme.CONSTRUCTOR, List(), List(List()), TypeTree(),
Block(List(Apply(Select(Super(This(tpnme.EMPTY), tpnme.EMPTY), nme.CONSTRUCTOR), List())), Literal(Constant(())))),
DefDef(Modifiers(), newTermName("unapply"), List(), List(List(ValDef(Modifiers(PARAM), newTermName("t"), Ident(newTypeName("Tree")), EmptyTree))), TypeTree(),
Match(
Ident(newTermName("t")), List(
CaseDef(Ident(newTermName("SomeTree")), EmptyTree, Apply(Ident(newTermName("Some")), List(Apply(Select(Ident(newTermName("scala")), newTermName("Tuple2")), List(Ident(newTermName("SomeTree")), Ident(newTermName("SomeTree"))))))),
CaseDef(Ident(nme.WILDCARD), EmptyTree, Ident(newTermName("None")))))))))),
Apply(Select(New(Ident(newTypeName("$anon"))), nme.CONSTRUCTOR), List())),
newTermName("unapply")),
List(t.tree)))
}
}
|
