[Expat-discuss] Terminating expat - idea

[Roskanuk Michal]

Hi,
i'd like just share idea of how to terminate expar processing
for any reason. This question appears periodically here (most
asked...), the logical answer is 'use exception in C++/Delphi
or setjmp/longjmp in C', which is - of course - ok. However
i guess for those who're looking for platform/compiler/etc
independent and a clear way (or are afraid of those mysterious
jmps ;-) the following way could be acceptable
(in scope of C language):

Create a struct, for example:

struct _XData
{
  int  err;                  // my own error number
  int  errln;                // on which line
  char errtxt[MAX_ERR_SIZE]; // optional additional info
...
}; // there is some missing, i know ;-)
typedef struct _XData XData;

and use it as userData. Main parsing loop:

...
XData x_data;
x_data.err = 0;
...
XML_SetUserData(parser, &x_data);
...
do
{
  // get data
  if(XML_Parse(parser, Buff, len, done) == XML_STATUS_ERROR)
    'handle parser error & bye
  else
    if(x_data.err > 0)
      'handle user error & bye or whatever
} while(are_there_some_data);

Then check x_data.err at the beginning of every handler,
for example:

static void start(void *data, const char *el, const char **attr)
{
  XData *px_data = (XData *) data;
  
  if(px_data->err > 0)
    return; // error occured somewhere, get out

and, of course fill out an error info whenever you
need followed by 'return' or 'goto CleanExit' or so.
This way makes code longer and a little bit slower,
but you're sure that everybody understands it and
it is totally portable (to every mind ;-).

Such workaround was posted already, however somebody
probably needs it roasted and with a soup, so i hope this helps.

Mike

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