public static AstNode ParseXPathPattern(string xpathPattern) {
XPathScanner scanner = new XPathScanner(xpathPattern);
XPathParser parser = new XPathParser(scanner);
AstNode result = parser.ParsePattern(null);
if (scanner.Kind != XPathScanner.LexKind.Eof) {
throw new XPathException(Res.Xp_InvalidToken, scanner.SourceText);
}
return result;
}
private static bool IsPrimaryExpr(XPathScanner scanner)
{
return(
scanner.Kind == XPathScanner.LexKind.String ||
scanner.Kind == XPathScanner.LexKind.Number ||
scanner.Kind == XPathScanner.LexKind.Dollar ||
scanner.Kind == XPathScanner.LexKind.LParens ||
scanner.Kind == XPathScanner.LexKind.Name && scanner.CanBeFunction && !IsNodeType(scanner)
);
}
private static bool IsNodeType(XPathScanner scaner)
{
return(
scaner.Prefix.Length == 0 && (
scaner.Name == "node" ||
scaner.Name == "text" ||
scaner.Name == "processing-instruction" ||
scaner.Name == "comment"
)
);
}
private Axis.AxisType GetAxis(XPathScanner scaner)
{
Debug.Assert(scaner.Kind == XPathScanner.LexKind.Axe);
object axis = AxesTable[scaner.Name];
if (axis == null)
{
throw new XPathException(Res.Xp_InvalidToken, scanner.SourceText);
}
return((Axis.AxisType)axis);
}
public static AstNode ParseXPathPattern(string xpathPattern)
{
XPathScanner scanner = new XPathScanner(xpathPattern);
XPathParser parser = new XPathParser(scanner);
AstNode result = parser.ParsePattern(null);
if (scanner.Kind != XPathScanner.LexKind.Eof)
{
throw new XPathException(Res.Xp_InvalidToken, scanner.SourceText);
}
return(result);
}
private XPathParser(XPathScanner scanner)
{
this.scanner = scanner;
}
private Axis.AxisType GetAxis(XPathScanner scaner) {
Debug.Assert(scaner.Kind == XPathScanner.LexKind.Axe);
object axis = AxesTable[scaner.Name];
if (axis == null) {
throw new XPathException(Res.Xp_InvalidToken, scanner.SourceText);
}
return (Axis.AxisType) axis;
}
void NextLex(XPathScanner.LexKind t) {
Debug.Assert(this.scanner.Kind == t);
NextLex();
}
void PassToken(XPathScanner.LexKind t) {
CheckToken(t);
NextLex();
}
// --------------- Helper methods ----------------------
void CheckToken(XPathScanner.LexKind t) {
if (this.scanner.Kind != t) {
throw new XPathException(Res.Xp_InvalidToken, this.scanner.SourceText);
}
}
private static bool IsPrimaryExpr(XPathScanner scanner) {
return (
scanner.Kind == XPathScanner.LexKind.String ||
scanner.Kind == XPathScanner.LexKind.Number ||
scanner.Kind == XPathScanner.LexKind.Dollar ||
scanner.Kind == XPathScanner.LexKind.LParens ||
scanner.Kind == XPathScanner.LexKind.Name && scanner.CanBeFunction && ! IsNodeType(scanner)
);
}
private static bool IsStep(XPathScanner.LexKind lexKind) {
return (
lexKind == XPathScanner.LexKind.Dot ||
lexKind == XPathScanner.LexKind.DotDot ||
lexKind == XPathScanner.LexKind.At ||
lexKind == XPathScanner.LexKind.Axe ||
lexKind == XPathScanner.LexKind.Star ||
lexKind == XPathScanner.LexKind.Name // NodeTest is also Name
);
}
private XPathParser(XPathScanner scanner) {
this.scanner = scanner;
}
private static bool IsNodeType(XPathScanner scaner) {
return (
scaner.Prefix.Length == 0 && (
scaner.Name == "node" ||
scaner.Name == "text" ||
scaner.Name == "processing-instruction" ||
scaner.Name == "comment"
)
);
}
private XPathParser(XPathScanner scanner) => _Scanner = scanner;
