com.github.tonivade.purefun.Function2 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;

import com.github.tonivade.purefun.type.Either;
import com.github.tonivade.purefun.type.Option;
import com.github.tonivade.purefun.type.Try;

/**
 * This interface represents a function with a two parameters. Similar to {@link java.util.function.BiFunction}.
 * The function can throws checked exceptions, but calling {@code apply()} method, the exception is sneaky thrown. So, it
 * can be used as a higher order function in {@link java.util.stream.Stream} or {@link java.util.Optional} API.
 * @param  type of first function parameter
 * @param  type of second function parameter
 * @param  type of return value
 */
@FunctionalInterface
public interface Function2 extends Recoverable {

  default R apply(A a, B b) {
    try {
      return run(a, b);
    } catch (Throwable t) {
      return sneakyThrow(t);
    }
  }

  R run(A a, B b) throws Throwable;

  default Function1> curried() {
    return a -> b -> apply(a, b);
  }

  default Function1, R> tupled() {
    return tuple -> apply(tuple.get1(), tuple.get2());
  }

  default  Function2 andThen(Function1 after) {
    return (a, b) -> after.apply(apply(a, b));
  }

  default  Function1 compose(Function1 beforeT, Function1 beforeV) {
    return value -> apply(beforeT.apply(value), beforeV.apply(value));
  }

  default Function2> liftTry() {
    return (a, b) -> Try.of(() -> apply(a, b));
  }

  default Function2> liftEither() {
    return liftTry().andThen(Try::toEither);
  }

  default Function2> liftOption() {
    return liftTry().andThen(Try::toOption);
  }

  default Function2 memoized() {
    return (a, b) -> new MemoizedFunction<>(tupled()).apply(Tuple.of(a, b));
  }

  static  Function2 of(Function2 reference) {
    return reference;
  }

  static  Function2 uncurried(Function1> function) {
    return (a, b) -> function.apply(a).apply(b);
  }

  static  Function2 cons(R value) {
    return (a, b) -> value;
  }

  static  Function2 first() {
    return (a, b) -> a;
  }

  static  Function2 second() {
    return (a, b) -> b;
  }
}