destructured

Typeclasses that provide data constructors of F[_], but parameterized by A instead of F[_].

Add the dependency:

libarary for Scala 3 (JS, JVM, and Native platforms)

"com.julianpeeters" %% "destructured" % "0.2.0"

Why?

This library may be useful if your model uses subtypes in its definition.

How?

The CtorOf typeclass is like ValueOf, but for constructors:

Scala's ValueOf provides values like None for singleton types,
here, CtorOf provides constructors like Some(_) for parameterized types

Example:

For example, if the compiler knows that a type A, is, at a call site, a Some[T] or a None.type, then destructured typeclasses can be used to summon a constructor for the underlying Some[T] or None.type:

import destructured.{CtorOf, given}

val a: Some[Int] = Some(1)
// a: Some[Int] = Some(value = 1)
def f[A](a: A)(using C: CtorOf[Int, A]): CtorOf[Int, A] = C
val b: Some[Int] = f(a).apply(2)
// b: Some[Int] = Some(value = 2)

(Note: For a more realistic example, see the dynamical library)

SupportedTypes:

Option	Either
Some	Left
None	Right

`Some[T]`

import destructured.{CtorOf, given}

val a: Some[Int] = Some(1)
// a: Some[Int] = Some(value = 1)
def f[A](a: A)(using C: CtorOf[Int, A]): CtorOf[Int, A] = C
val b: Some[Int] = f(a).apply(2)
// b: Some[Int] = Some(value = 2)

`None.type`

import destructured.{CtorOf, given}

val a: None.type = None
// a: None = None
def f[A](a: A)(using C: CtorOf[Int, A]): CtorOf[Int, A] = C
val b: None.type = f(a).apply(2)
// b: None = None

`Right[L, R]`

import destructured.{CtorOf, given}

val a: Right[Boolean, Int] = Right(1)
// a: Right[Boolean, Int] = Right(value = 1)
def f[A](a: A)(using C: CtorOf[Int, A]): CtorOf[Int, A] = C
val b: Right[Boolean, Int] = f(a).apply(2)
// b: Right[Boolean, Int] = Right(value = 2)

`Left[L, R]`

import destructured.{CtorOf, given}

val a: Left[Boolean, Int] = Left(false)
// a: Left[Boolean, Int] = Left(value = false)
def f[A](a: A)(using C: CtorOf[Boolean, A]): CtorOf[Boolean, A] = C
val b: Left[Boolean, Int] = f(a).apply(true)
// b: Left[Boolean, Int] = Left(value = true)

julianpeeters / destructured 0.2.0