org.javimmutable.collections.sequence.EmptySequenceNode Maven / Gradle / Ivy

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package org.javimmutable.collections.sequence;

import org.javimmutable.collections.InsertableSequence;

import javax.annotation.Nonnull;
import javax.annotation.concurrent.Immutable;

@Immutable
public final class EmptySequenceNode
    implements InsertableSequence
{
    private static final InsertableSequence EMPTY = new EmptySequenceNode();

    private EmptySequenceNode()
    {
    }

    @SuppressWarnings("unchecked")
    public static  InsertableSequence of()
    {
        return (InsertableSequence)EMPTY;
    }

    @Nonnull
    @Override
    public InsertableSequence insert(T value)
    {
        return FilledSequenceNode.of(value);
    }

    @Override
    public boolean isEmpty()
    {
        return true;
    }

    @Override
    public T getHead()
    {
        throw new UnsupportedOperationException();
    }

    @Nonnull
    @Override
    public InsertableSequence getTail()
    {
        throw new UnsupportedOperationException();
    }
}