I have repetitive blocks of code I want to copy, like old C-style macros. I'm trying quasiquotes:
import scala.language.experimental.macros
object CodeBlock {
val quasi = q"""def foo() = {"bar"}"""
}
case class A() {
// ??? want quasi here
}
case class B() {
// ??? want quasi here
}
Try macro annotation
import scala.annotation.{StaticAnnotation, compileTimeOnly}
import scala.language.experimental.macros
import scala.reflect.macros.whitebox
@compileTimeOnly("enable macro paradise")
class codeBlock extends StaticAnnotation {
def macroTransform(annottees: Any*): Any = macro CodeBlockMacro.impl
}
object CodeBlockMacro {
def impl(c: whitebox.Context)(annottees: c.Tree*): c.Tree = {
import c.universe._
annottees match {
case q"$mods class $tpname[..$tparams] $ctorMods(...$paramss) extends { ..$earlydefns } with ..$parents { $self => ..$stats }" :: tail =>
q"""
$mods class $tpname[..$tparams] $ctorMods(...$paramss) extends { ..$earlydefns } with ..$parents { $self =>
def foo() = {"bar"}
..$stats
}
..$tail
"""
}
}
}
@codeBlock
case class A()
@codeBlock
case class B()
//Warning:scalac: {
// case class A extends scala.Product with scala.Serializable {
// def <init>() = {
// super.<init>();
// ()
// };
// def foo() = "bar"
// };
// ()
//}
//Warning:scalac: {
// case class B extends scala.Product with scala.Serializable {
// def <init>() = {
// super.<init>();
// ()
// };
// def foo() = "bar"
// };
// ()
//}
class Foo { def bar = macro myMacroGenBody }