Varargs

object Varargs

Expression representation of literal sequence of expressions.

Varargs can be used to create the an expression args that will be used as varargs '{ f($args: _*) } or it can be used to extract all the arguments of the a varargs.

Source:
Varargs.scala
class Object
trait Matchable
class Any

Value members

Concrete methods

def apply[T](xs: Seq[Expr[T]])(using Type[T])(using Quotes): Expr[Seq[T]]

Lifts this sequence of expressions into an expression of a sequence

Lifts this sequence of expressions into an expression of a sequence

Transforms a sequence of expression Seq(e1, e2, ...) where ei: Expr[T] to an expression equivalent to '{ Seq($e1, $e2, ...) } typed as an Expr[Seq[T]]

Usage:

package scala.quoted
trait Snippet0 { self: quoted.Varargs.type =>
  def f(using Quotes) = {
  import quotes.reflect.*
  '{ List(${Varargs(List('{1}, '{2}, '{3}))}: _*) } // equivalent to '{ List(1, 2, 3) }
  }
}
Source:
Varargs.scala
def unapply[T](expr: Expr[Seq[T]])(using Quotes): Option[Seq[Expr[T]]]

Matches a literal sequence of expressions and return a sequence of expressions.

Matches a literal sequence of expressions and return a sequence of expressions.

Usage:

object O {
inline def sum(args: Int*): Int = ${ sumExpr('args) }
def sumExpr(argsExpr: Expr[Seq[Int]])(using Quotes): Expr[Int] = argsExpr match
  case Varargs(argVarargs) =>
    // argVarargs: Seq[Expr[Int]]
    ???
}
Source:
Varargs.scala