I can't find a way to work properly with Xpath in the cpp runtime of ANTLR4. Precisely, I have noticed that the path.split(..) function always returns an empty vector. As a result the function path.evaluate(context) always returns the unmodified (input) context parameter.
I was expecting to get at least two Xpath elements (root // and wildecar *) with the following code :
const std::string xpath_str ="//*/ID"; antlr4::tree::xpath::XPath path(&parser, xpath_str); std::vector<tree::xpath::XPathElement> elements = path.split(xpath_str); std::cout << "Nb XpAth Elements :"<< elements.size() << std::endl; but it returns 0 elements.
Can you help me with this ?
ps: I raised an issue about it on Github because I'm not sure whether the problem is in the cpp runtime or not.
EDIT
I found a minor bug in the current release of the Cpp runtime.
The code in xPath.cpp :
std::vector<XPathElement> XPath::split(const std::string &path) { ANTLRFileStream in(path); should be replaced by :
std::vector<XPathElement> XPath::split(const std::string &path) { ANTLRInputStream in(path); otherwise the split function doesn't behave as in other runtime (it expect a file instead of a string).
I have made a pull request.
However the Xpath feature still doesn't work.
The following code always return an empty string (I'm sure of the value of the xpath as it works with the c# runtime)
const std::string xpath_enum = "*//enumerator/Identifier"; antlr4::tree::xpath::XPath finder(_parser, xpath_enum); std::vector<antlr4::tree::ParseTree *>subtrees = finder.evaluate(context); Can anyone help me with this ?
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