com.github.tonivade.purefun.instances.EIOInstances 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.EIO;
import com.github.tonivade.purefun.effect.EIOOf;
import com.github.tonivade.purefun.effect.EIO_;
import com.github.tonivade.purefun.effect.UIO;
import com.github.tonivade.purefun.typeclasses.Applicative;
import com.github.tonivade.purefun.typeclasses.Bracket;
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 EIOInstances {

  static  Functor> functor() {
    return EIOFunctor.INSTANCE;
  }

  static  Applicative> applicative() {
    return EIOApplicative.INSTANCE;
  }

  static  Monad> monad() {
    return EIOMonad.INSTANCE;
  }

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

  static MonadThrow> monadThrow() {
    return EIOMonadThrow.INSTANCE;
  }

  static MonadDefer> monadDefer() {
    return EIOMonadDefer.INSTANCE;
  }

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

interface EIOFunctor extends Functor> {

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

  @Override
  default  EIO
          map(Kind, A> value, Function1 map) {
    return EIOOf.narrowK(value).map(map);
  }
}

interface EIOPure extends Applicative> {

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

interface EIOApplicative extends EIOPure {

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

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

interface EIOMonad extends EIOPure, Monad> {

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

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

interface EIOMonadError extends EIOMonad, MonadError, E> {

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

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

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

interface EIOMonadThrow
    extends EIOMonadError,
            MonadThrow> {

  EIOMonadThrow INSTANCE = new EIOMonadThrow() {};
}

interface EIODefer extends Defer> {

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

interface EIOBracket extends Bracket> {

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

interface EIOMonadDefer
    extends MonadDefer>, EIOMonadThrow, EIODefer, EIOBracket {

  EIOMonadDefer INSTANCE = new EIOMonadDefer() {};

  @Override
  default EIO sleep(Duration duration) {
    return UIO.sleep(duration).toEIO();
  }
}