////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2017 Saxonica Limited.
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is "Incompatible With Secondary Licenses", as defined by the Mozilla Public License, v. 2.0.
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

package net.sf.saxon.expr;

import net.sf.saxon.expr.parser.ContextItemStaticInfo;
import net.sf.saxon.expr.parser.ExpressionTool;
import net.sf.saxon.expr.parser.ExpressionVisitor;
import net.sf.saxon.trans.XPathException;

/**
 * An EagerLetExpression is the same as a LetExpression except that the variable is evaluated using
 * eager evaluation rather than lazy evaluation. This is used when performing diagnostic tracing.
 */

public class EagerLetExpression extends LetExpression {

    public EagerLetExpression() {
    }

    /*@NotNull*/
    public Expression optimize(ExpressionVisitor visitor, ContextItemStaticInfo contextItemType) throws XPathException {
        Expression e = super.optimize(visitor, contextItemType);
        if (e == this) {
            setEvaluationMode(ExpressionTool.eagerEvaluationMode(getSequence()));
        }
        return e;
    }

}


