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//
// Burton Computer Corporation
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package org.javimmutable.collections.array;

import org.javimmutable.collections.Holder;
import org.javimmutable.collections.Holders;
import org.javimmutable.collections.JImmutableMap;
import org.javimmutable.collections.iterators.GenericIterator;

import javax.annotation.Nullable;
import javax.annotation.concurrent.Immutable;

@Immutable
class EmptyTrieNode
    extends TrieNode
{
    private static final EmptyTrieNode EMPTY = new EmptyTrieNode();

    @SuppressWarnings("unchecked")
    static  EmptyTrieNode instance()
    {
        return EMPTY;
    }

    @Override
    public int valueCount()
    {
        return 0;
    }

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

    @Override
    public T getValueOr(int shift,
                        int index,
                        T defaultValue)
    {
        return defaultValue;
    }

    @Override
    public Holder find(int shift,
                          int index)
    {
        return Holders.of();
    }

    @Override
    public TrieNode assign(int shift,
                              int index,
                              T value)
    {
        return LeafTrieNode.of(index, value);
    }

    @Override
    public TrieNode delete(int shift,
                              int index)
    {
        return this;
    }

    @Override
    public int getShift()
    {
        return 0;
    }

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

    @Override
    public TrieNode paddedToMinimumDepthForShift(int shift)
    {
        return this;
    }

    @Nullable
    @Override
    public GenericIterator.State> iterateOverRange(@Nullable GenericIterator.State> parent,
                                                                                   int offset,
                                                                                   int limit)
    {
        return parent;
    }

    @Override
    public void checkInvariants()
    {
    }
}