gecko-dev/dom/xslt/xpath/txBooleanExpr.cpp

82 строки
2.1 KiB
C++

/* -*- 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