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Raúl Raja Martínez raulraja

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raulraja / adt_bound_constrain.kt
Created May 28, 2021 17:30
Constraint ADT for Flow Action and Reaction emit
/** 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
raulraja / DBEffect.kt
Created January 15, 2021 11:53
Demo for https://kotlinlang.slack.com/archives/C5UPMM0A0/p1610705745005100?thread_ts=1610678990.003600&cid=C5UPMM0A0
package dbactions
import arrow.continuations.Effect
import arrow.continuations.generic.DelimitedScope
import kotlin.reflect.KClass
/**
* An abstract connection
*/
interface Connection {
@raulraja
raulraja / TwitterHandle.kt
Created February 20, 2020 12:16
Type Refinements with Type Proofs in Kotlin
/* Coming up ~ April 2020 */
package test
import arrow.*
inline class TwitterHandle(val handle: String) {
companion object : Refined<String> {
override val validate: String.() -> Map<String, Boolean> = {
mapOf(
"Should start with '@'" to startsWith("@"),
@raulraja
raulraja / st.kt
Created November 14, 2020 19:26
Marco's question in slack
package arrow.prelude.test
import arrow.continuations.generic.DelimContScope
import arrow.continuations.generic.DelimitedScope
abstract class ST<S, A> @PublishedApi internal constructor() {
companion object {
operator fun <S, A> invoke(a: () -> A): ST<S, A> {
val memo by lazy(a)
return object : ST<S, A>() {
@raulraja
raulraja / IO.kt
Created April 17, 2020 20:06
Kinds without uncheched casts
/** Bifunctor IO */
class IO<out E, out A> :
`*`<IO<*, *>>,
`*-*`<IO<*, *>, A>,
`*-*-*`<IO<*, *>, E, A> {
fun <B> fmap(f: (A) -> B): IO<Nothing, B> = TODO()
fun <B> flatMap(f: (A) -> `*-*`<IO<*, *>, B>): IO<Nothing, B> = TODO()
fun <C, D> bimap(fl: (E) -> C, fr: (A) -> D): IO<C, D> = TODO()
companion object {
@raulraja
raulraja / AutoCancellation.kt
Last active March 8, 2020 12:15
Arrow Fx. Auto cancels without leaving to user discipline to check for `isAlive`. Examples by @nomisRev
import arrow.fx.*
import arrow.fx.extensions.*
import arrow.fx.typeclasses.*
import arrow.fx.extensions.io.bracket.guaranteeCase
fun <A> IOOf<A>.onCancel(token: IOOf<Unit>): IO<A> =
guaranteeCase { case ->
when (case) {
ExitCase.Canceled -> token
else -> IO.unit
@raulraja
raulraja / rules.kt
Created March 5, 2020 17:51
Validation rules abstracting strategies with operations as extension functions
package arrow.rules.test
import arrow.Kind
import arrow.core.Either
import arrow.core.EitherPartialOf
import arrow.core.Nel
import arrow.core.NonEmptyList
import arrow.core.Validated
import arrow.core.ValidatedPartialOf
import arrow.core.extensions.either.applicativeError.applicativeError
@raulraja
raulraja / Tagless.kt
Last active January 20, 2020 15:53
Tagless in Kotlin with Arrow and manual DI
import arrow.Kind
import arrow.core.Option
import arrow.core.Try
import arrow.core.functor
import arrow.effects.IO
import arrow.effects.fix
import arrow.effects.functor
import arrow.typeclasses.Functor
/* algebras */
@raulraja
raulraja / prelude.kt
Created January 7, 2020 23:16
Daydreaming proofs as contracts
package arrow.meta.ide.plugins.proofs.contracts
import kotlin.contracts.Effect
import kotlin.contracts.ExperimentalContracts
interface TypeLevelEffect : Effect
interface Declaration : Effect
fun declaration(): Declaration = TODO()
@raulraja
raulraja / toStringReplacement.meta.kt
Created November 5, 2019 12:48
[toString] replacement, originally discussed in https://kotlinlang.slack.com/archives/C7L3JB43G/p1572884683059400
package arrow.meta.plugins.helloWorld
import arrow.meta.Meta
import arrow.meta.Plugin
import arrow.meta.invoke
import arrow.meta.phases.analysis.ElementScope
import arrow.meta.quotes.ClassScope
import arrow.meta.quotes.Scope
import arrow.meta.quotes.Transform
import arrow.meta.quotes.classOrObject