Move FUUIDVar#unapply into FUUID?

[gabro]

FUUIDVar from the http4s module simply defines an unapply method, which is "standard" and not specific to http4s in any way.

Could it make sense to move that unapply into the core FUUID object so that one would get path extractors out of the box without the extra dependency?

import io.chrisdavenport.fuuid.FUUID

Path("/v1/16a30838-5e02-4e68-a1bc-585e42594430") match {
  case Root / "v1" / FUUID(uuid) => // do something with uuid
  case _ => // nope
}

I understand that conceptually the unapply method is there to support http4s extractors, but it could technically be useful in any other match clause regardless of https.
This is a result of the cool design of http4s' DSL, and it would be interesting to exploit it :)

The http4s module is still useful for http4s-specific things like #69

[ChristopherDavenport]

The type having an unapply that exposes itself internally seems odd, and exposing something that interacts with the underlying is unsafe in a way I would prefer not to expose.

How do you see this being used outside of http4s dsl?

[gabro]

One example I have from a project of mine goes a follows:

import io.estatico.newtype.macros.newtype
import io.chrisdavenport.fuuid.FUUID
import io.chrisdavenport.fuuid.http4s.FUUIDVar

@newtype case class UserId(value: FUUID)
object UserId {
  def unapply(str: String): Option[UserId] = FUUIDVar.unapply(str).map(UserId(_))
}

And I will then use UserId.unapply in pattern matches outside of the http4s DSL.

In this case, I had to bring in FUUIDVar from the http4s package even though I'm not using http4s at all.

Anyway, this is just an example, and I'm not particularly attached to the proposal. It just seemed strange to be forced to depend on the http4s package for something (unapply) that is potentially unrelated.

[ChristopherDavenport]

I would think using the core types would be more direct. Since it doesn't go through the indirection. We could probably put a helper in to do the option conversion.

https://github.com/ChristopherDavenport/fuuid/blob/series/0.2/modules/core/src/main/scala/io/chrisdavenport/fuuid/FUUID.scala#L36

def unapply(str: String): Option[UserId] = 
  FUUID.fromString(str).map(UserId(_)).toOption

[ChristopherDavenport]

If using #85 - this could be FUUID.fromStringOpt(str).map(UserId(_))

I guess I'm not seeing what the unapply is exposing. As its not part of a larger hierarchy or any other system that it could be yanked out of generally.

However I basically only use unapply for the http4s dsl use.

[gabro]

Yeah, a fromStringOpt method is definitely a good solution. Thanks for the feedback and for the API addition 👍