package treeNAlgo;

import treeN.*;

/**
 * Splits host upwards if its state > order and passes the host to the
 * supplied param, which is an ISpliceCmd, to do some "abstract splicing".
 * @dependency treeNAlgo.ILambda uses
 */
class SplitUpAndApply implements ITreeNAlgo {

    private int _order;
    /**
     * Installs no-op cmd for states <= order
     */
    public SplitUpAndApply(int order) {
	_order = order;
    }

    public Object caseAt(int s, TreeN host, Object cmd) {
	if (s <= _order) {
	    return host;
	}
	else {
	    host.splitUpAt(s/2);   // push data up
	    return ((ILambda)cmd).apply(host); // "splice" host into something!
	}
    }

}