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Common utility classes used by Permazen.

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/*
 * Copyright (C) 2015 Archie L. Cobbs. All rights reserved.
 */

package io.permazen.index;

import io.permazen.tuple.Tuple2;
import io.permazen.util.Bounds;

import java.util.NavigableMap;
import java.util.NavigableSet;

/**
 * An index on a single field.
 *
 * 
 * Indexes are read-only and "live", always reflecting the current transaction state.
 *
 * @param  indexed value type
 * @param  index target type
 * @see io.permazen.index
 */
public interface Index1 extends Index {

    @Override
    default int numberOfFields() {
        return 1;
    }

    /**
     * View this index as a {@link NavigableSet} of tuples.
     *
     * @return {@link NavigableSet} of tuples containing indexed value and target value
     */
    NavigableSet> asSet();

    /**
     * View this index as a {@link NavigableMap} of target values keyed by indexed value.
     *
     * @return {@link NavigableMap} from indexed value to the corresponding set of target objects
     */
    NavigableMap> asMap();

    /**
     * Impose {@link Bounds} that restrict the range of the indexed value.
     *
     * @param bounds bounds to impose on the indexed value
     * @return a view of this index in which only values within {@code bounds} are visible
     */
    Index1 withValueBounds(Bounds bounds);

    /**
     * Impose {@link Bounds} that restrict the range of the target value.
     *
     * @param bounds bounds to impose on the target value
     * @return a view of this index in which only target values within {@code bounds} are visible
     */
    Index1 withTargetBounds(Bounds bounds);
}