New types (and unwrapping)

By default, smithy4s will wrap all standalone primitive types in a Newtype. A standalone primitive type is one that is defined like the following:

string Email // standalone primitive

structure Test {
  email: Email
  other: String // not a standalone primitive
}

Given this example, smithy4s would generate something like the following:

final case class Test(email: Email, other: String)

This wrapping may be undesirable in some circumstances. As such, we've provided the smithy4s.meta#unwrap trait. This trait tells the smithy4s code generation to not wrap these types in a newtype when they are used.

use smithy4s.meta#unwrap

@unwrap
string Email

structure Test {
  email: Email
  other: String
}

This would now generate something like:

final case class Test(email: String, other: String)

This can be particularly useful when working with refinement types (see above for details on refinements). By default, any type that is refined will be generated inside of a newtype. If you don't want this, you can mark the type with the unwrap trait.

@trait(selector: "string")
structure emailFormat {}

@emailFormat
@unwrap
string Email

info

By default, smithy4s renders collection types as unwrapped EXCEPT when the collection has been refined. In this case, the collection will be rendered within a newtype by default. If you wish your refined collection be rendered unwrapped, you can accomplish this using the same @unwrap trait annotation on it.