flabbergast.MergeIterator Maven / Gradle / Ivy

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package flabbergast;

import java.util.Iterator;
import java.util.Map;
import java.util.SortedMap;
import java.util.TreeMap;

/**
 * Iterate over the keys of several of frames and templates.
 */

public class MergeIterator {
    private Map.Entry current;

    private final SortedMap dispatchers = new TreeMap();

    private final int exit_dispatcher;

    private Iterator> iterator;

    private long position;

    public MergeIterator(Iterable[] inputs, int default_dispatcher,
                         int exit_dispatcher) {
        this.exit_dispatcher = exit_dispatcher;
        for (Iterable input : inputs) {
            for (String key : input) {
                dispatchers.put(key, default_dispatcher);
            }
        }
    }

    /**
     * Add dispatcher for a particular key name.
     *
     * When the key is encoutered, this dispatcher will be returned, instead of
     * the default dispatcher in the constructor. Added dispatchers are always
     * invoked, even if they do not occur in the input key space.
     */

    public void addDispatcher(String name, int dispatcher) {
        dispatchers.put(name, dispatcher);
    }

    /**
     * The current attribute name.
     */
    public String getCurrent() {
        return current.getKey();
    }

    public Stringish getCurrentish() {
        return new SimpleStringish(current.getKey());
    }

    /**
     * The current attribute ordinal, 1-based per the language spec.
     */
    public long getPosition() {
        return position;
    }

    public int next() {
        if (iterator == null) {
            iterator = dispatchers.entrySet().iterator();
        }
        if (iterator.hasNext()) {
            current = iterator.next();
            position++;
            return current.getValue();
        }
        return exit_dispatcher;
    }
}