org.javimmutable.collections.tree.DeleteResult Maven / Gradle / Ivy

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//
// Burton Computer Corporation
// http://www.burton-computer.com
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// Copyright (c) 2017, Burton Computer Corporation
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package org.javimmutable.collections.tree;

import javax.annotation.concurrent.Immutable;

@SuppressWarnings("unchecked")
@Immutable
public class DeleteResult
{
    private static final DeleteResult UNCHANGED = new DeleteResult(Type.UNCHANGED, null);
    private static final DeleteResult ELIMINATED = new DeleteResult(Type.ELIMINATED, EmptyNode.INSTANCE);

    public enum Type
    {
        UNCHANGED,
        INPLACE,
        ELIMINATED,
        REMNANT
    }

    public final Type type;
    public final TreeNode node;

    private DeleteResult(Type type,
                         TreeNode node)
    {
        this.type = type;
        this.node = node;
    }

    public static  DeleteResult createUnchanged()
    {
        return (DeleteResult)UNCHANGED;
    }

    public static  DeleteResult createInPlace(TreeNode node)
    {
        return new DeleteResult(Type.INPLACE, node);
    }

    public static  DeleteResult createEliminated()
    {
        return (DeleteResult)ELIMINATED;
    }

    public static  DeleteResult createRemnant(TreeNode node)
    {
        return new DeleteResult(Type.REMNANT, node);
    }

    @Override
    public String toString()
    {
        switch (type) {
        case UNCHANGED:
            return "unchanged";
        case INPLACE:
            return String.format("inplace:%s", node);
        case ELIMINATED:
            return "eliminated";
        case REMNANT:
            return String.format("remnant:%s", node);
        }
        throw new IllegalStateException();
    }

    @SuppressWarnings("RedundantIfStatement")
    @Override
    public boolean equals(Object o)
    {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }

        DeleteResult that = (DeleteResult)o;

        if (node != null ? !node.equals(that.node) : that.node != null) {
            return false;
        }
        if (type != that.type) {
            return false;
        }

        return true;
    }

    @Override
    public int hashCode()
    {
        int result = type != null ? type.hashCode() : 0;
        result = 31 * result + (node != null ? node.hashCode() : 0);
        return result;
    }
}