dom/xslt/xpath/txRelationalExpr.cpp

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "txExpr.h"
   7 #include "txNodeSet.h"
   8 #include "txIXPathContext.h"
   9 #include "txXPathTreeWalker.h"
  10
  11 /**
  12  *  Compares the two ExprResults based on XPath 1.0 Recommendation (section 3.4)
  13  */
  14 bool RelationalExpr::compareResults(txIEvalContext* aContext,
  15                                     txAExprResult* aLeft,
  16                                     txAExprResult* aRight) {
  17   short ltype = aLeft->getResultType();
  18   short rtype = aRight->getResultType();
  19   nsresult rv = NS_OK;
  20
  21   // Handle case for just Left NodeSet or Both NodeSets
  22   if (ltype == txAExprResult::NODESET) {
  23     if (rtype == txAExprResult::BOOLEAN) {
  24       BooleanResult leftBool(aLeft->booleanValue());
  25       return compareResults(aContext, &leftBool, aRight);
  26     }
  27
  28     txNodeSet* nodeSet = static_cast<txNodeSet*>(aLeft);
  29     RefPtr<StringResult> strResult;
  30     rv = aContext->recycler()->getStringResult(getter_AddRefs(strResult));
  31     NS_ENSURE_SUCCESS(rv, false);
  32
  33     int32_t i;
  34     for (i = 0; i < nodeSet->size(); ++i) {
  35       strResult->mValue.Truncate();
  36       txXPathNodeUtils::appendNodeValue(nodeSet->get(i), strResult->mValue);
  37       if (compareResults(aContext, strResult, aRight)) {
  38         return true;
  39       }
  40     }
  41
  42     return false;
  43   }
  44
  45   // Handle case for Just Right NodeSet
  46   if (rtype == txAExprResult::NODESET) {
  47     if (ltype == txAExprResult::BOOLEAN) {
  48       BooleanResult rightBool(aRight->booleanValue());
  49       return compareResults(aContext, aLeft, &rightBool);
  50     }
  51
  52     txNodeSet* nodeSet = static_cast<txNodeSet*>(aRight);
  53     RefPtr<StringResult> strResult;
  54     rv = aContext->recycler()->getStringResult(getter_AddRefs(strResult));
  55     NS_ENSURE_SUCCESS(rv, false);
  56
  57     int32_t i;
  58     for (i = 0; i < nodeSet->size(); ++i) {
  59       strResult->mValue.Truncate();
  60       txXPathNodeUtils::appendNodeValue(nodeSet->get(i), strResult->mValue);
  61       if (compareResults(aContext, aLeft, strResult)) {
  62         return true;
  63       }
  64     }
  65
  66     return false;
  67   }
  68
  69   // Neither is a NodeSet
  70   if (mOp == EQUAL || mOp == NOT_EQUAL) {
  71     bool result;
  72     const nsString *lString, *rString;
  73
  74     // If either is a bool, compare as bools.
  75     if (ltype == txAExprResult::BOOLEAN || rtype == txAExprResult::BOOLEAN) {
  76       result = aLeft->booleanValue() == aRight->booleanValue();
  77     }
  78
  79     // If either is a number, compare as numbers.
  80     else if (ltype == txAExprResult::NUMBER || rtype == txAExprResult::NUMBER) {
  81       double lval = aLeft->numberValue();
  82       double rval = aRight->numberValue();
  83       result = (lval == rval);
  84     }
  85
  86     // Otherwise compare as strings. Try to use the stringobject in
  87     // StringResult if possible since that is a common case.
  88     else if ((lString = aLeft->stringValuePointer())) {
  89       if ((rString = aRight->stringValuePointer())) {
  90         result = lString->Equals(*rString);
  91       } else {
  92         nsAutoString rStr;
  93         aRight->stringValue(rStr);
  94         result = lString->Equals(rStr);
  95       }
  96     } else if ((rString = aRight->stringValuePointer())) {
  97       nsAutoString lStr;
  98       aLeft->stringValue(lStr);
  99       result = rString->Equals(lStr);
 100     } else {
 101       nsAutoString lStr, rStr;
 102       aLeft->stringValue(lStr);
 103       aRight->stringValue(rStr);
 104       result = lStr.Equals(rStr);
 105     }
 106
 107     return mOp == EQUAL ? result : !result;
 108   }
 109
 110   double leftDbl = aLeft->numberValue();
 111   double rightDbl = aRight->numberValue();
 112   switch (mOp) {
 113     case LESS_THAN: {
 114       return (leftDbl < rightDbl);
 115     }
 116     case LESS_OR_EQUAL: {
 117       return (leftDbl <= rightDbl);
 118     }
 119     case GREATER_THAN: {
 120       return (leftDbl > rightDbl);
 121     }
 122     case GREATER_OR_EQUAL: {
 123       return (leftDbl >= rightDbl);
 124     }
 125     default: {
 126       MOZ_ASSERT_UNREACHABLE("We should have caught all cases");
 127     }
 128   }
 129
 130   return false;
 131 }
 132
 133 nsresult RelationalExpr::evaluate(txIEvalContext* aContext,
 134                                   txAExprResult** aResult) {
 135   *aResult = nullptr;
 136   RefPtr<txAExprResult> lResult;
 137   nsresult rv = mLeftExpr->evaluate(aContext, getter_AddRefs(lResult));
 138   NS_ENSURE_SUCCESS(rv, rv);
 139
 140   RefPtr<txAExprResult> rResult;
 141   rv = mRightExpr->evaluate(aContext, getter_AddRefs(rResult));
 142   NS_ENSURE_SUCCESS(rv, rv);
 143
 144   aContext->recycler()->getBoolResult(
 145       compareResults(aContext, lResult, rResult), aResult);
 146
 147   return NS_OK;
 148 }
 149
 150 TX_IMPL_EXPR_STUBS_2(RelationalExpr, BOOLEAN_RESULT, mLeftExpr, mRightExpr)
 151
 152 bool RelationalExpr::isSensitiveTo(ContextSensitivity aContext) {
 153   return mLeftExpr->isSensitiveTo(aContext) ||
 154          mRightExpr->isSensitiveTo(aContext);
 155 }
 156
 157 #ifdef TX_TO_STRING
 158 void RelationalExpr::toString(nsAString& str) {
 159   mLeftExpr->toString(str);
 160
 161   switch (mOp) {
 162     case NOT_EQUAL:
 163       str.AppendLiteral("!=");
 164       break;
 165     case LESS_THAN:
 166       str.Append(char16_t('<'));
 167       break;
 168     case LESS_OR_EQUAL:
 169       str.AppendLiteral("<=");
 170       break;
 171     case GREATER_THAN:
 172       str.Append(char16_t('>'));
 173       break;
 174     case GREATER_OR_EQUAL:
 175       str.AppendLiteral(">=");
 176       break;
 177     default:
 178       str.Append(char16_t('='));
 179       break;
 180   }
 181
 182   mRightExpr->toString(str);
 183 }
 184 #endif