/**
* Try to precompile the arguments to the function. This method is shared by the implementations
* of the three XPath functions matches(), replace(), and tokenize().
*
* @param args the supplied arguments to the function, as an array
* @param patternArg the position of the argument containing the regular expression
* @param flagsArg the position of the argument containing the flags
* @return the compiled regular expression, or null indicating that the information is not
* available statically so it cannot be precompiled
* @throws XPathException if any failure occurs, in particular, if the regular expression is
* invalid
*/
public static RegularExpression tryToCompile(
Expression[] args, int patternArg, int flagsArg, StaticContext env) throws XPathException {
if (patternArg > args.length - 1) {
// too few arguments were supplied; the error will be reported in due course
return null;
}
CharSequence flagstr = null;
if (args.length - 1 < flagsArg) {
flagstr = "";
} else if (args[flagsArg] instanceof StringValue) {
flagstr = ((StringValue) args[flagsArg]).getStringValueCS();
}
if (args[patternArg] instanceof StringValue && flagstr != null) {
try {
Platform platform = env.getConfiguration().getPlatform();
CharSequence in = ((StringValue) args[patternArg]).getStringValueCS();
RegularExpression regexp = platform.compileRegularExpression(in, true, flagstr);
return regexp;
} catch (XPathException err) {
StaticError e2 = new StaticError(err.getMessage());
e2.setErrorCode("FORX0002");
throw e2;
}
} else {
return null;
}
}
public void checkArguments(StaticContext env) throws XPathException {
if (checked) return;
checked = true;
super.checkArguments(env);
Optimizer opt = env.getConfiguration().getOptimizer();
argument[1] = ExpressionTool.unsorted(opt, argument[1], false);
if (argument[0] instanceof StringValue) {
// common case, key name is supplied as a constant
try {
keyFingerprint =
((ExpressionContext) env)
.getFingerprint(((StringValue) argument[0]).getStringValue(), false);
} catch (XPathException e) {
StaticError err =
new StaticError(
"Error in key name "
+ ((StringValue) argument[0]).getStringValue()
+ ": "
+ e.getMessage());
err.setLocator(this);
err.setErrorCode("XTDE1260");
throw err;
}
if (keyFingerprint == -1) {
StaticError err =
new StaticError(
"Key " + ((StringValue) argument[0]).getStringValue() + " has not been defined");
err.setLocator(this);
err.setErrorCode("XTDE1260");
throw err;
}
} else {
// we need to save the namespace context
nsContext = env.getNamespaceResolver();
}
}