raulraja

package demo

import arrow.core.Either
import arrow.core.None
import arrow.core.Option
import arrow.core.Some
import arrow.core.continuations.Raise
import arrow.core.continuations.effect
import arrow.core.continuations.either
import arrow.core.continuations.toEither

raulraja

Pre-SIP: Suspended functions and continuations in Scala 3.

This Pre-SIP post proposes continuations as a new language feature in Scala 3.

It has been prepared by Jack Viers, Raul Raja and reviewed by the Scala 3 team at 47 Degrees. This doc is intended to be used as a way to gather community feedback and foster discussion.

Motivation

Our observation in the industry and among our peers is that most programming in Scala today that involves async or I/O-based programs targets a monadic indirect boxed style.

raulraja

package org.coral.fp.control

import arrow.core.ValidatedNel
import arrow.core.invalidNel
import arrow.core.validNel
import arrow.core.zip
import kotlin.jvm.JvmInline

@JvmInline
public value class ProductId private constructor(public val value: Int) {

raulraja

package examples

import arrow.core.Either
import arrow.core.continuations.EffectScope
import arrow.core.continuations.either

object Request
object Response
sealed interface Error
object InvalidRequest : Error

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package arrow.core

public fun interface Partial<A, B, C, D, Z> {
  public operator fun invoke(a: A, b: B, c: C, d: D): Z

  public fun first(a: A): Partial<Unit, B, C, D, Z> =
    Partial { _, b, c, d -> invoke(a, b, c, d) }

  public fun second(b: B): Partial<A, Unit, C, D, Z> =
    Partial { a, _, c, d -> invoke(a, b, c, d) }

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package arrow.meta.continuations

import arrow.core.Either
import arrow.core.computations.either
import arrow.core.flatMap

/**
 * Models errors as values
 */
sealed interface Failure

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package arrow.derive

/**
 * An Algebraic data type [Type] can derive behaviors
 * for its members
 */
sealed class Derive<in Type> {
  /**
   * Derived instances associated to [Type]
   */

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Given validation steps

1. Only top level class, object, property or function can be @Given declarations

@Given fun <T> et(@Given eq: Eq<T>): Eq<Tree<T>> = ...

2. Declarations with Value parameters annotated as @Given for injection must

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/** Dummy login model **/
@JvmInline
value class UserName(val value: String)

@JvmInline
value class Password(val value: String)

/**
 * A [Reaction] is always parametric to a type of [Action]
 */

raulraja

package dbactions

import arrow.continuations.Effect
import arrow.continuations.generic.DelimitedScope
import kotlin.reflect.KClass

/**
 * An abstract connection
 */
interface Connection {