xpathfunctions.cpp

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    }

    if (!node)
        node = evaluationContext().node.get();

    return node->namespaceURI().string();
}

Value FunName::evaluate() const
{
    Node* node = 0;
    if (argCount() > 0) {
        Value a = arg(0)->evaluate();
        if (!a.isNodeSet())
            return "";

        node = a.toNodeSet().firstNode();
        if (!node)
            return "";
    }

    if (!node)
        node = evaluationContext().node.get();

    const AtomicString& prefix = node->prefix();
    return prefix.isEmpty() ? node->localName().string() : prefix + ":" + node->localName();
}

Value FunCount::evaluate() const
{
    Value a = arg(0)->evaluate();
    
    if (!a.isNodeSet())
        return 0.0;
    
    return double(a.toNodeSet().size());
}

Value FunString::evaluate() const
{
    if (!argCount())
        return Value(Expression::evaluationContext().node.get()).toString();
    return arg(0)->evaluate().toString();
}

Value FunConcat::evaluate() const
{
    Vector<UChar, 1024> result;

    unsigned count = argCount();
    for (unsigned i = 0; i < count; ++i) {
        String str(arg(i)->evaluate().toString());
        result.append(str.characters(), str.length());
    }

    return String(result.data(), result.size());
}

Value FunStartsWith::evaluate() const
{
    String s1 = arg(0)->evaluate().toString();
    String s2 = arg(1)->evaluate().toString();

    if (s2.isEmpty())
        return true;

    return s1.startsWith(s2);
}

Value FunContains::evaluate() const
{
    String s1 = arg(0)->evaluate().toString();
    String s2 = arg(1)->evaluate().toString();

    if (s2.isEmpty()) 
        return true;

    return s1.contains(s2) != 0;
}

Value FunSubstringBefore::evaluate() const
{
    String s1 = arg(0)->evaluate().toString();
    String s2 = arg(1)->evaluate().toString();

    if (s2.isEmpty())
        return "";

    int i = s1.find(s2);

    if (i == -1)
        return "";

    return s1.left(i);
}

Value FunSubstringAfter::evaluate() const
{
    String s1 = arg(0)->evaluate().toString();
    String s2 = arg(1)->evaluate().toString();

    int i = s1.find(s2);
    if (i == -1)
        return "";

    return s1.substring(i + s2.length());
}

Value FunSubstring::evaluate() const
{
    String s = arg(0)->evaluate().toString();
    long pos = static_cast<long>(FunRound::round(arg(1)->evaluate().toNumber()));
    bool haveLength = argCount() == 3;
    long len = -1;
    if (haveLength) {
        double doubleLen = arg(2)->evaluate().toNumber();
        if (isnan(doubleLen))
            return "";
        len = static_cast<long>(FunRound::round(doubleLen));
    }

    if (pos > long(s.length())) 
        return "";

    if (haveLength && pos < 1) {
        len -= 1 - pos;
        pos = 1;
        if (len < 1)
            return "";
    }

    return s.substring(pos - 1, len);
}

Value FunStringLength::evaluate() const
{
    if (!argCount())
        return Value(Expression::evaluationContext().node.get()).toString().length();
    return arg(0)->evaluate().toString().length();
}

Value FunNormalizeSpace::evaluate() const
{
    if (!argCount()) {
        String s = Value(Expression::evaluationContext().node.get()).toString();
        return s.simplifyWhiteSpace();
    }

    String s = arg(0)->evaluate().toString();
    return s.simplifyWhiteSpace();
}

Value FunTranslate::evaluate() const
{
    String s1 = arg(0)->evaluate().toString();
    String s2 = arg(1)->evaluate().toString();
    String s3 = arg(2)->evaluate().toString();
    String newString;

    // FIXME: Building a String a character at a time is quite slow.
    for (unsigned i1 = 0; i1 < s1.length(); ++i1) {
        UChar ch = s1[i1];
        int i2 = s2.find(ch);
        
        if (i2 == -1)
            newString += String(&ch, 1);
        else if ((unsigned)i2 < s3.length()) {
            UChar c2 = s3[i2];
            newString += String(&c2, 1);
        }
    }

    return newString;
}

Value FunBoolean::evaluate() const
{
    return arg(0)->evaluate().toBoolean();
}

Value FunNot::evaluate() const
{
    return !arg(0)->evaluate().toBoolean();
}

Value FunTrue::evaluate() const
{
    return true;
}

Value FunLang::evaluate() const
{
    String lang = arg(0)->evaluate().toString();

    Attribute* languageAttribute = 0;
    Node* node = evaluationContext().node.get();
    while (node) {
        NamedAttrMap* attrs = node->attributes();
        if (attrs)
            languageAttribute = attrs->getAttributeItem(XMLNames::langAttr);
        if (languageAttribute)
            break;
        node = node->parentNode();
    }

    if (!languageAttribute)
        return false;

    String langValue = languageAttribute->value();
    while (true) {
        if (equalIgnoringCase(langValue, lang))
            return true;

        // Remove suffixes one by one.
        int index = langValue.reverseFind('-');
        if (index == -1)
            break;
        langValue = langValue.left(index);
    }

    return false;
}

Value FunFalse::evaluate() const
{
    return false;
}

Value FunNumber::evaluate() const
{
    if (!argCount())
        return Value(Expression::evaluationContext().node.get()).toNumber();
    return arg(0)->evaluate().toNumber();
}

Value FunSum::evaluate() const
{
    Value a = arg(0)->evaluate();
    if (!a.isNodeSet())
        return 0.0;

    double sum = 0.0;
    const NodeSet& nodes = a.toNodeSet();
    // To be really compliant, we should sort the node-set, as floating point addition is not associative.
    // However, this is unlikely to ever become a practical issue, and sorting is slow.

    for (unsigned i = 0; i < nodes.size(); i++)
        sum += Value(stringValue(nodes[i])).toNumber();
    
    return sum;
}

Value FunFloor::evaluate() const
{
    return floor(arg(0)->evaluate().toNumber());
}

Value FunCeiling::evaluate() const
{
    return ceil(arg(0)->evaluate().toNumber());
}

double FunRound::round(double val)
{
    if (!isnan(val) && !isinf(val)) {
        if (signbit(val) && val >= -0.5)
            val *= 0; // negative zero
        else
            val = floor(val + 0.5);
    }
    return val;
}

Value FunRound::evaluate() const
{
    return round(arg(0)->evaluate().toNumber());
}

static void createFunctionMap()
{
    struct FunctionMapping {
        const char *name;
        FunctionRec function;
    };
    static const FunctionMapping functions[] = {
        { "boolean", { &createFunBoolean, 1 } },
        { "ceiling", { &createFunCeiling, 1 } },
        { "concat", { &createFunConcat, Interval(2, Interval::Inf) } },
        { "contains", { &createFunContains, 2 } },
        { "count", { &createFunCount, 1 } },
        { "false", { &createFunFalse, 0 } },
        { "floor", { &createFunFloor, 1 } },
        { "id", { &createFunId, 1 } },
        { "lang", { &createFunLang, 1 } },
        { "last", { &createFunLast, 0 } },
        { "local-name", { &createFunLocalName, Interval(0, 1) } },
        { "name", { &createFunName, Interval(0, 1) } },
        { "namespace-uri", { &createFunNamespaceURI, Interval(0, 1) } },
        { "normalize-space", { &createFunNormalizeSpace, Interval(0, 1) } },
        { "not", { &createFunNot, 1 } },
        { "number", { &createFunNumber, Interval(0, 1) } },
        { "position", { &createFunPosition, 0 } },
        { "round", { &createFunRound, 1 } },
        { "starts-with", { &createFunStartsWith, 2 } },
        { "string", { &createFunString, Interval(0, 1) } },
        { "string-length", { &createFunStringLength, Interval(0, 1) } },
        { "substring", { &createFunSubstring, Interval(2, 3) } },
        { "substring-after", { &createFunSubstringAfter, 2 } },
        { "substring-before", { &createFunSubstringBefore, 2 } },
        { "sum", { &createFunSum, 1 } },
        { "translate", { &createFunTranslate, 3 } },
        { "true", { &createFunTrue, 0 } },
    };
    const unsigned int numFunctions = sizeof(functions) / sizeof(functions[0]);

    functionMap = new HashMap<String, FunctionRec>;
    for (unsigned i = 0; i < numFunctions; ++i)
        functionMap->set(functions[i].name, functions[i].function);
}

Function* createFunction(const String& name, const Vector<Expression*>& args)
{
    if (!functionMap)
        createFunctionMap();

    HashMap<String, FunctionRec>::iterator functionMapIter = functionMap->find(name);
    FunctionRec* functionRec = 0;

    if (functionMapIter == functionMap->end() || !(functionRec = &functionMapIter->second)->args.contains(args.size()))
        return 0;

    Function* function = functionRec->factoryFn();
    function->setArguments(args);
    function->setName(name);
    return function;
}

}
}

#endif // ENABLE(XPATH)