[xml] How "subject to change" is xmlRelaxNGParse()'s interface...

[Sean Chittenden <sean chittenden org>]

The subject says it all.  In relaxng.c, around line 7212 it says:

### BEGIN
/**
 * xmlRelaxNGParse:
 * @ctxt:  a Relax-NG parser context
 *
 * parse a schema definition resource and build an internal
 * XML Shema struture which can be used to validate instances.
 * *WARNING* this interface is highly subject to change
 *
 * Returns the internal XML RelaxNG structure built from the resource or
 *         NULL in case of error
 */
xmlRelaxNGPtr
xmlRelaxNGParse(xmlRelaxNGParserCtxtPtr ctxt)
...
#### END

... So I'm curious as to how subject to change this method is, esp 
given it's the only way to get an xmlRelaxNGPtr from an 
xmlRelaxNGParserCtxtPtr.  Are there any plans or would patches be 
accepted to simplify the process of sucking in a RelaxNG file and 
making it available as an xmlRelaxNGValidCtxtPtr?  Seems like every 
program that I have that uses a RelaxNG schema goes through the same 
hoops to obtain a schema that I can validate an xmlDocPtr with.  It'd 
be slick if there was a function like:

xmlRelaxNGValidCtxtPtr
xmlRelaxNGReadFile(char *filename, char *encoding, int options) {
  xmlRelaxNGValidCtxtPtr ret;
  xmlRelaxNGParserCtxtPtr rngctxt;
  xmlDocPtr doc;

  doc = xmlReadFile(filename, encoding, options);
  if (doc == NULL)
    return(NULL)

  rngctxt = xmlRelaxNGNewDocParserCtxt(doc);
  if (rngctxt == NULL) {
    xmlDocFree(doc);
    return(NULL);
  }

  rng = xmlRelaxNGParse(rngctxt);
  if (rng == NULL) {
    xmlDocFree(doc);
    xmlRelaxNGFreeParserCtxt(rngctxt);
    return(NULL);
  }

  ret = xmlRelaxNGNewValidCtxt(rng);
  if (ret == NULL) {
    xmlDocFree(doc);
    xmlRelaxNGFreeParserCtxt(rngctxt);
    xmlRelaxNGFree(rng);
    return(NULL);
  }

  return(ret);
}

Because then it lowers the coding overhead to just two function calls, 
getting the xmlRelaxNGValidCtxtPtr and then calling 
xmlRelaxNGValidateDoc().  Just a thought.  -sc

--
Sean Chittenden