Using existing methods in macro - scala

Question

Suppose i have some class with some methods
class Clz ... {
def someMethod: Map[String, Long] = ...
def id: Long = 0L
}
i'm need to reuse someMethod and overwrite id
i don't know why but it's throw Stackoverflow and also i'm need to do something with params/methods of Clz without returning the result
what i've tried:
object Macros {
def impl(c: whitebox.Context)(annottees: c.Tree*): c.Tree = {
import c.universe._
annottees match {
case (cls # q"$_ class $tpname[..$_] $_(...$paramss) extends { ..$_ } with ..$_ { $_ => ..$stats }") :: Nil =>
val someMethodM = stats
.filter(case q"$_ def $methodName: $_ = $_" => methodName.toString == "someMethod")
.map {
case q"$_ def $_: $_ = $res" => res
}
q"""
$cls
object ClzCompanion {
val someMethodsRef: Map[String, Int] = Map.apply(..$someMethodM)
..${
paramss
.flatten
.foreach {
case q"$_ val $nname: $tpt = $valuee" =>
// simply do something with valuee and nothing else
// "fire and forget"
}
}
..${
paramss
.flatten
.map {
case q"$_ val $nname: $tpt = $valuee" =>
// here logic, if this nname in someMethodsRef then
// someMethodsRef.find({ case (key, _) => key == nname) match {
// case Some(_) => "def $nname: ($tpt, Int) = ... // new method with body
// case None => do nothing...
}
}
}
"""
}
}
}
how i can overwrite the id method at Clz?
and why it throws StackOverflow??