com.github.tonivade.purefun.instances.ZIOInstances Maven / Gradle / Ivy

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/*
 * Copyright (c) 2018-2020, Antonio Gabriel Muñoz Conejo 
 * Distributed under the terms of the MIT License
 */
package com.github.tonivade.purefun.instances;

import java.time.Duration;
import com.github.tonivade.purefun.Consumer1;
import com.github.tonivade.purefun.Function1;
import com.github.tonivade.purefun.Kind;
import com.github.tonivade.purefun.Producer;
import com.github.tonivade.purefun.Unit;
import com.github.tonivade.purefun.effect.UIO;
import com.github.tonivade.purefun.effect.ZIO;
import com.github.tonivade.purefun.effect.ZIOOf;
import com.github.tonivade.purefun.effect.ZIO_;
import com.github.tonivade.purefun.typeclasses.Applicative;
import com.github.tonivade.purefun.typeclasses.Bracket;
import com.github.tonivade.purefun.typeclasses.Console;
import com.github.tonivade.purefun.typeclasses.Defer;
import com.github.tonivade.purefun.typeclasses.Functor;
import com.github.tonivade.purefun.typeclasses.Monad;
import com.github.tonivade.purefun.typeclasses.MonadDefer;
import com.github.tonivade.purefun.typeclasses.MonadError;
import com.github.tonivade.purefun.typeclasses.MonadThrow;
import com.github.tonivade.purefun.typeclasses.Reference;
import com.github.tonivade.purefun.typeclasses.Resource;

@SuppressWarnings("unchecked")
public interface ZIOInstances {

  static  Functor, E>> functor() {
    return ZIOFunctor.INSTANCE;
  }

  static  Applicative, E>> applicative() {
    return ZIOApplicative.INSTANCE;
  }

  static  Monad, E>> monad() {
    return ZIOMonad.INSTANCE;
  }

  static  MonadError, E>, E> monadError() {
    return ZIOMonadError.INSTANCE;
  }

  static  MonadThrow, Throwable>> monadThrow() {
    return ZIOMonadThrow.INSTANCE;
  }

  static  MonadDefer, Throwable>> monadDefer() {
    return ZIOMonadDefer.INSTANCE;
  }

  static  Reference, Throwable>, A> ref(A value) {
    return Reference.of(monadDefer(), value);
  }
  
  static  Resource, Throwable>, A> resource(
      ZIO acquire) {
    return resource(acquire, AutoCloseable::close);
  }
  
  static  Resource, Throwable>, A> resource(
      ZIO acquire, Consumer1 release) {
    return Resource.from(monadDefer(), acquire, release);
  }

  static  Console, Throwable>> console() {
    return ConsoleZIO.INSTANCE;
  }
}

interface ZIOFunctor extends Functor, E>> {

  @SuppressWarnings("rawtypes")
  ZIOFunctor INSTANCE = new ZIOFunctor() {};

  @Override
  default  ZIO
          map(Kind, E>, A> value, Function1 map) {
    return ZIOOf.narrowK(value).map(map);
  }
}

interface ZIOPure extends Applicative, E>> {

  @Override
  default  ZIO pure(A value) {
    return ZIO.pure(value);
  }
}

interface ZIOApplicative extends ZIOPure {

  @SuppressWarnings("rawtypes")
  ZIOApplicative INSTANCE = new ZIOApplicative() {};

  @Override
  default  ZIO
          ap(Kind, E>, A> value,
             Kind, E>, Function1> apply) {
    return ZIOOf.narrowK(apply).flatMap(map -> ZIOOf.narrowK(value).map(map));
  }
}

interface ZIOMonad extends ZIOPure, Monad, E>> {

  @SuppressWarnings("rawtypes")
  ZIOMonad INSTANCE = new ZIOMonad() {};

  @Override
  default  ZIO
          flatMap(Kind, E>, A> value,
                  Function1, E>, B>> map) {
    return ZIOOf.narrowK(value).flatMap(map.andThen(ZIOOf::narrowK));
  }
}

interface ZIOMonadError extends ZIOMonad, MonadError, E>, E> {

  @SuppressWarnings("rawtypes")
  ZIOMonadError INSTANCE = new ZIOMonadError() {};

  @Override
  default  ZIO raiseError(E error) {
    return ZIO.raiseError(error);
  }

  @Override
  default  ZIO
          handleErrorWith(Kind, E>, A> value,
                          Function1, E>, A>> handler) {
    // XXX: java8 fails to infer types, I have to do this in steps
    Function1> mapError = handler.andThen(ZIOOf::narrowK);
    Function1> map = ZIO::pure;
    ZIO zio = ZIOOf.narrowK(value);
    return zio.foldM(mapError, map);
  }
}

interface ZIOMonadThrow
    extends ZIOMonadError,
            MonadThrow, Throwable>> {
  @SuppressWarnings("rawtypes")
  ZIOMonadThrow INSTANCE = new ZIOMonadThrow() {};
}

interface ZIODefer extends Defer, Throwable>> {

  @Override
  default  ZIO
          defer(Producer, Throwable>, A>> defer) {
    return ZIO.defer(() -> defer.map(ZIOOf::narrowK).get());
  }
}

interface ZIOBracket extends Bracket, Throwable>> {

  @Override
  default  ZIO
          bracket(Kind, Throwable>, A> acquire,
                  Function1, Throwable>, B>> use,
                  Consumer1 release) {
    return ZIO.bracket(acquire.fix(ZIOOf::narrowK), use.andThen(ZIOOf::narrowK), release);
  }
}

interface ZIOMonadDefer
    extends MonadDefer, Throwable>>, ZIOMonadThrow, ZIODefer, ZIOBracket {

  @SuppressWarnings("rawtypes")
  ZIOMonadDefer INSTANCE = new ZIOMonadDefer() {};

  @Override
  default ZIO sleep(Duration duration) {
    return UIO.sleep(duration).toZIO();
  }
}

final class ConsoleZIO implements Console, Throwable>> {

  @SuppressWarnings("rawtypes")
  protected static final ConsoleZIO INSTANCE = new ConsoleZIO();

  private final SystemConsole console = new SystemConsole();

  @Override
  public ZIO readln() {
    return ZIO.task(console::readln);
  }

  @Override
  public ZIO println(String text) {
    return ZIO.exec(() -> console.println(text));
  }
}