// $Id: SequenceComposeExpr.java,v 1.1 2002/04/25 18:11:23 bill Exp $

package com.jclark.xsl.expr;

import com.jclark.xsl.om.*;

/**
 * Composition when expr1 is SINGLE_LEVEL and expr2 is STAYS_IN_SUBTREE.
 */

class SequenceComposeExpr extends ConvertibleNodeSetExpr {
    private final ConvertibleNodeSetExpr expr1;
    private final ConvertibleNodeSetExpr expr2;

    SequenceComposeExpr(ConvertibleNodeSetExpr expr1, ConvertibleNodeSetExpr expr2) {
        this.expr1 = expr1;
        this.expr2 = expr2;
    }

    public NodeIterator eval(Node node, ExprContext context) throws XSLException {
        return new SequenceComposeNodeIterator(expr1.eval(node, context),
                                               expr2,
                                               context);
    }

    int getOptimizeFlags() {
        // if expr2 is SINGLE_LEVEL then this will be too
        return expr2.getOptimizeFlags();
    }
}