Consider the following example:
import shapeless._
case class Foo(bar: String, baz: Boolean)
val labl = LabelledGeneric[Foo]
Now, the type of labl
is (prettified)
LabelledGeneric[Foo] {
type Repr =
FieldType[Symbol @@ String("bar"), String] ::
FieldType[Symbol @@ String("baz"), Boolean] ::
HNil
}
which already conveys the information I need, i.e. the names of the case class fields.
What I'm looking for is a way to go from labl
to something along the lines of
"bar" :: "baz" :: HNil
i.e. materializing the information contained in the singleton types into a value.
Is this possible?
I could use a macro, but I feel like I would end up rewriting something very similar to the GenericMacros
object in shapeless, so I'm wondering whether I can leverage it directly.
You can obtain the keys of the record (as Symbol
s) via shapeless.ops.record.Keys
.
This
import shapeless._
import shapeless.ops.record._
case class Foo(bar: String, baz: Boolean)
val labl = LabelledGeneric[Foo]
val keys = Keys[labl.Repr].apply
println(keys)
println(keys.toList.map(_.name))
results in
'bar :: 'baz :: HNil
List(bar, baz) : List(String)
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