io.github.cwdesautels.monad.ImmutableFailure Maven / Gradle / Ivy

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package io.github.cwdesautels.monad;

import io.github.cwdesautels.annotation.Nullable;
import java.util.Objects;
import org.immutables.value.Generated;

/**
 * Immutable implementation of {@link Failure}.
 * 
 * Use the builder to create immutable instances:
 * {@code ImmutableFailure.builder()}.
 */
@Generated(from = "Failure", generator = "Immutables")
@SuppressWarnings({"all"})
@javax.annotation.processing.Generated("org.immutables.processor.ProxyProcessor")
final class ImmutableFailure implements Failure {
  private final @Nullable Throwable cause;

  private ImmutableFailure(@Nullable Throwable cause) {
    this.cause = cause;
  }

  /**
   * @return The value of the {@code cause} attribute
   */
  @Override
  public @Nullable Throwable getCause() {
    return cause;
  }

  /**
   * Copy the current immutable object by setting a value for the {@link Failure#getCause() cause} attribute.
   * A shallow reference equality check is used to prevent copying of the same value by returning {@code this}.
   * @param value A new value for cause (can be {@code null})
   * @return A modified copy of the {@code this} object
   */
  public final ImmutableFailure withCause(@Nullable Throwable value) {
    if (this.cause == value) return this;
    return new ImmutableFailure<>(value);
  }

  /**
   * This instance is equal to all instances of {@code ImmutableFailure} that have equal attribute values.
   * @return {@code true} if {@code this} is equal to {@code another} instance
   */
  @Override
  public boolean equals(Object another) {
    if (this == another) return true;
    return another instanceof ImmutableFailure
        && equalTo((ImmutableFailure) another);
  }

  private boolean equalTo(ImmutableFailure another) {
    return Objects.equals(cause, another.cause);
  }

  /**
   * Computes a hash code from attributes: {@code cause}.
   * @return hashCode value
   */
  @Override
  public int hashCode() {
    int h = 5381;
    h += (h << 5) + Objects.hashCode(cause);
    return h;
  }

  /**
   * Prints the immutable value {@code Failure} with attribute values.
   * @return A string representation of the value
   */
  @Override
  public String toString() {
    return "Failure{"
        + "cause=" + cause
        + "}";
  }

  /**
   * Creates an immutable copy of a {@link Failure} value.
   * Uses accessors to get values to initialize the new immutable instance.
   * If an instance is already immutable, it is returned as is.
   * @param  generic parameter T
   * @param instance The instance to copy
   * @return A copied immutable Failure instance
   */
  public static  ImmutableFailure copyOf(Failure instance) {
    if (instance instanceof ImmutableFailure) {
      return (ImmutableFailure) instance;
    }
    return ImmutableFailure.builder()
        .from(instance)
        .build();
  }

  /**
   * Creates a builder for {@link ImmutableFailure ImmutableFailure}.
   * 
   * ImmutableFailure.&lt;T&gt;builder()
   *    .cause(Throwable | null) // nullable {@link Failure#getCause() cause}
   *    .build();
   * 
   * @param  generic parameter T
   * @return A new ImmutableFailure builder
   */
  public static  ImmutableFailure.Builder builder() {
    return new ImmutableFailure.Builder<>();
  }

  /**
   * Builds instances of type {@link ImmutableFailure ImmutableFailure}.
   * Initialize attributes and then invoke the {@link #build()} method to create an
   * immutable instance.
   * {@code Builder} is not thread-safe and generally should not be stored in a field or collection,
   * but instead used immediately to create instances.
   */
  @Generated(from = "Failure", generator = "Immutables")
  public static final class Builder {
    private Throwable cause;

    private Builder() {
    }

    /**
     * Fill a builder with attribute values from the provided {@code io.github.cwdesautels.monad.Try} instance.
     * @param instance The instance from which to copy values
     * @return {@code this} builder for use in a chained invocation
     */
    public final Builder from(Try instance) {
      Objects.requireNonNull(instance, "instance");
      from((Object) instance);
      return this;
    }

    /**
     * Fill a builder with attribute values from the provided {@code io.github.cwdesautels.monad.Failure} instance.
     * @param instance The instance from which to copy values
     * @return {@code this} builder for use in a chained invocation
     */
    public final Builder from(Failure instance) {
      Objects.requireNonNull(instance, "instance");
      from((Object) instance);
      return this;
    }

    @SuppressWarnings("unchecked")
    private void from(Object object) {
      long bits = 0;
      if (object instanceof Try) {
        Try instance = (Try) object;
        if ((bits & 0x1L) == 0) {
          @Nullable Throwable causeValue = instance.getCause();
          if (causeValue != null) {
            cause(causeValue);
          }
          bits |= 0x1L;
        }
      }
      if (object instanceof Failure) {
        Failure instance = (Failure) object;
        if ((bits & 0x1L) == 0) {
          @Nullable Throwable causeValue = instance.getCause();
          if (causeValue != null) {
            cause(causeValue);
          }
          bits |= 0x1L;
        }
      }
    }

    /**
     * Initializes the value for the {@link Failure#getCause() cause} attribute.
     * @param cause The value for cause (can be {@code null})
     * @return {@code this} builder for use in a chained invocation
     */
    public final Builder cause(@Nullable Throwable cause) {
      this.cause = cause;
      return this;
    }

    /**
     * Builds a new {@link ImmutableFailure ImmutableFailure}.
     * @return An immutable instance of Failure
     * @throws java.lang.IllegalStateException if any required attributes are missing
     */
    public ImmutableFailure build() {
      return new ImmutableFailure<>(cause);
    }
  }
}