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lightning-sunbird  0.9+nobinonly
BooleanExpr.cpp
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00001 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
00002 /* ***** BEGIN LICENSE BLOCK *****
00003  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
00004  *
00005  * The contents of this file are subject to the Mozilla Public License Version
00006  * 1.1 (the "License"); you may not use this file except in compliance with
00007  * the License. You may obtain a copy of the License at
00008  * http://www.mozilla.org/MPL/
00009  *
00010  * Software distributed under the License is distributed on an "AS IS" basis,
00011  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
00012  * for the specific language governing rights and limitations under the
00013  * License.
00014  *
00015  * The Original Code is TransforMiiX XSLT processor code.
00016  *
00017  * The Initial Developer of the Original Code is
00018  * The MITRE Corporation.
00019  * Portions created by the Initial Developer are Copyright (C) 1999
00020  * the Initial Developer. All Rights Reserved.
00021  *
00022  * Contributor(s):
00023  *   Keith Visco <kvisco@ziplink.net> (Original Author)
00024  *
00025  * Alternatively, the contents of this file may be used under the terms of
00026  * either the GNU General Public License Version 2 or later (the "GPL"), or
00027  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
00028  * in which case the provisions of the GPL or the LGPL are applicable instead
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00035  * the terms of any one of the MPL, the GPL or the LGPL.
00036  *
00037  * ***** END LICENSE BLOCK ***** */
00038 
00039 
00045 #include "Expr.h"
00046 #include "ExprResult.h"
00047 #include "txIXPathContext.h"
00048 
00056 nsresult
00057 BooleanExpr::evaluate(txIEvalContext* aContext, txAExprResult** aResult)
00058 {
00059     *aResult = nsnull;
00060 
00061     nsRefPtr<txAExprResult> exprRes;
00062     nsresult rv = leftExpr->evaluate(aContext, getter_AddRefs(exprRes));
00063     NS_ENSURE_SUCCESS(rv, rv);
00064     
00065     PRBool lval = exprRes->booleanValue();
00066 
00067     // check for early decision
00068     if (op == OR && lval) {
00069         aContext->recycler()->getBoolResult(PR_TRUE, aResult);
00070         
00071         return NS_OK;
00072     }
00073     if (op == AND && !lval) {
00074         aContext->recycler()->getBoolResult(PR_FALSE, aResult);
00075 
00076         return NS_OK;
00077     }
00078 
00079     rv = rightExpr->evaluate(aContext, getter_AddRefs(exprRes));
00080     NS_ENSURE_SUCCESS(rv, rv);
00081 
00082     // just use rval, since we already checked lval
00083     aContext->recycler()->getBoolResult(exprRes->booleanValue(), aResult);
00084 
00085     return NS_OK;
00086 } //-- evaluate
00087 
00088 #ifdef TX_TO_STRING
00089 void
00090 BooleanExpr::toString(nsAString& str)
00091 {
00092     if ( leftExpr ) leftExpr->toString(str);
00093     else str.AppendLiteral("null");
00094 
00095     switch ( op ) {
00096         case OR:
00097             str.AppendLiteral(" or ");
00098             break;
00099         default:
00100             str.AppendLiteral(" and ");
00101             break;
00102     }
00103     if ( rightExpr ) rightExpr->toString(str);
00104     else str.AppendLiteral("null");
00105 
00106 }
00107 #endif