/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

/* 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/. */

/**

 * Represents a BooleanExpr, a binary expression that

 * performs a boolean operation between its lvalue and rvalue.

**/

#include "txExpr.h"

#include "txIXPathContext.h"

/**

 * Evaluates this Expr based on the given context node and processor state

 * @param context the context node for evaluation of this Expr

 * @param ps the ContextState containing the stack information needed

 * for evaluation

 * @return the result of the evaluation

**/

nsresult

BooleanExpr::evaluate(txIEvalContext* aContext, txAExprResult** aResult)

{

    *aResult = nullptr;

    bool lval;

    nsresult rv = leftExpr->evaluateToBool(aContext, lval);

    NS_ENSURE_SUCCESS(rv, rv);

    // check for early decision

    if (op == OR && lval) {

        aContext->recycler()->getBoolResult(true, aResult);

        return NS_OK;

    }

    if (op == AND && !lval) {

        aContext->recycler()->getBoolResult(false, aResult);

        return NS_OK;

    }

    bool rval;

    rv = rightExpr->evaluateToBool(aContext, rval);

    NS_ENSURE_SUCCESS(rv, rv);

    // just use rval, since we already checked lval

    aContext->recycler()->getBoolResult(rval, aResult);

    return NS_OK;

} //-- evaluate

TX_IMPL_EXPR_STUBS_2(BooleanExpr, BOOLEAN_RESULT, leftExpr, rightExpr)

bool

BooleanExpr::isSensitiveTo(ContextSensitivity aContext)

{

    return leftExpr->isSensitiveTo(aContext) ||

           rightExpr->isSensitiveTo(aContext);

}

#ifdef TX_TO_STRING

void

BooleanExpr::toString(nsAString& str)

{

    if ( leftExpr ) leftExpr->toString(str);

    else str.AppendLiteral("null");

    switch ( op ) {

        case OR:

            str.AppendLiteral(" or ");

            break;

        default:

            str.AppendLiteral(" and ");

            break;

    }

    if ( rightExpr ) rightExpr->toString(str);

    else str.AppendLiteral("null");

}

#endif