CODEWITHSUNDEEP
scalascala-macros
cedric
cedric

Reputation: 358

scala class member macro implementation

I always thought that macro declarations and implementation need to be defined as in the tutorials:

object Impl {
    def m(c: Context)(body: c.Expr[Unit]): c.Expr[T] = ???
}
class Usage {
    def m(body: Unit): T = macro Impl.m = ???
}

However now I came across:

class RecordMacros(val c: Context) {
    import c.universe._
    def apply_impl[Rep: c.WeakTypeTag](method: c.Expr[String])(v: c.Expr[(String, Any)]*): c.Expr[Any] = ???
}

source: https://github.com/TiarkRompf/virtualization-lms-core/blob/macro-trans/src/common/Records.scala

What is the difference, is it about refactoring the context out from each method? Also the class doesn't seem to be instantiated before the method is accessed. Thanks

Upvotes: 2

Views: 130

Answers (1)

cvogt
cvogt

Reputation: 11270

They are called macro bundles available in 2.11 only and yes that's what they are for. http://docs.scala-lang.org/overviews/macros/bundles.html

Upvotes: 4

Related Questions