/// <summary>
/// Tries to parse the xpath expression
/// </summary>
/// <param name="xpath">
/// is the xpath string. </param>
/// <param name="isRootlessAccess">
/// if 'true' then PsychoPath engine can't parse xpath expressions starting with / or //. </param>
/// <exception cref="XPathParserException."> </exception>
/// <returns> the xpath value.
/// @since 2.0 </returns>
public virtual XPath parse(string xpath, bool isRootlessAccess)
{
var lexer = new XPath31Lexer(new AntlrInputStream(xpath));
try
{
lexer.RemoveErrorListeners();
var lexer_error_listener = new ErrorListener <int>(null, lexer, 3);
lexer.AddErrorListener(lexer_error_listener);
var tokens = new CommonTokenStream(lexer);
var parser = new XPath31Parser(tokens);
parser.RemoveErrorListeners();
var parser_error_listener = new ErrorListener <IToken>(parser, lexer, 3);
parser.AddErrorListener(parser_error_listener);
XPath31Parser.XpathContext parse_tree = parser.xpath();
if (lexer_error_listener.had_error || parser_error_listener.had_error)
{
throw new XPathParserException("ANTLR parser error");
}
var sb = new OutputParseTree().OutputTree(parse_tree, tokens, parser, true);
// Compute AST representation of XPath expression.
var visitor = XPathBuilderVisitor.INSTANCE;
var xPath2 = (XPath)visitor.VisitXpath(parse_tree);
xPath2.Expression = xpath;
var o = new org.eclipse.wst.xml.xpath2.processor.@internal.OutputXPathExpression();
var sb2 = o.OutputTree(xPath2).ToString();
//System.Console.WriteLine("==============================");
//System.Console.WriteLine("IR for expression \"" + xpath + "\"");
//System.Console.WriteLine("Expression \"" + xpath + "\"");
//System.Console.WriteLine(sb2.ToString());
if (isRootlessAccess)
{
}
return(xPath2);
}
catch (StaticError e)
{
throw new XPathParserException(e.code(), e.Message);
}
catch (Exception e)
{
throw new XPathParserException(e.Message);
}
}
static void Try(string ffn)
{
System.IO.StreamReader file = new System.IO.StreamReader(ffn);
string line;
while ((line = file.ReadLine()) != null)
{
System.Console.WriteLine("===== Expression =====");
System.Console.WriteLine(line);
var str = new AntlrInputStream(line);
var lexer = new XPath31Lexer(str);
var tokens = new CommonTokenStream(lexer);
var parser = new XPath31Parser(tokens);
var listener = new ErrorListener <IToken>(parser, lexer, tokens);
parser.AddErrorListener(listener);
var tree = parser.xpath();
if (listener.had_error)
{
System.Console.WriteLine("error in parse.");
System.Console.WriteLine(tokens.OutputTokens());
System.Console.WriteLine(tree.OutputTree(tokens));
return;
}
else
{
System.Console.WriteLine(tokens.OutputTokens());
System.Console.WriteLine(tree.OutputTree(tokens));
System.Console.WriteLine("parse completed.");
}
string xpath = "//exprsingle";
var names = Antlr4.Runtime.Tree.Xpath.XPath.FindAll(tree, xpath, parser);
foreach (var n in names)
{
System.Console.WriteLine("match " + n.GetText());
}
}
}