Re: [xml] xmlHashScan and *data argument

[Melvyn Sopacua <mdev idg nl>]

On Sunday 19 October 2003 23:43, Daniel Veillard wrote:
> On Sun, Oct 19, 2003 at 11:31:54PM +0200, Melvyn Sopacua wrote:
> Content-Description: signed data
>
> > On Sunday 19 October 2003 23:01, Daniel Veillard wrote:
> > > On Sun, Oct 19, 2003 at 10:43:33PM +0200, Melvyn Sopacua wrote:
> > > Content-Description: signed data
> > >
> > > > This works:
> > > > =====================================================================
> > > > === void printElementStructured(xmlElementPtr el)
> > >
> > > [...]
> > >
> > > > This doesn't:
> > > > =====================================================================
> > > > === void printElementStructured(int *level, xmlElementPtr el)
> > > > {
> > >
> > > [...]
> > >
> > > >         xmlHashScan(table, (xmlHashScanner) printElementStructured, &level);

For the first version, the call to xmlHashScan is:
xmlHashScan(table, (xmlHashScanner) printElementStructured, NULL);

so there is no data argument passed.
Just to be clear: these are two tries for the same program.

> > >  And you're surprised ?
> > >  Your problem is the use of the C language apparently. You cannot
> > > expect to shuffle arguments and have the compiler guess magically that
> > > your interface changed and reorder arguments.
> >
> > Ehm - then I don't know why your own code in valid.c works.
>
>   I don't see the point. I just looked at your mail, and if the first
> version works, then obviously the second version cannot work.
>
> > How is the second version different from:
>
>   I dunno. So then your first version should not work, but you reported it
> as "working", but you can't obviously have both "working".

I still don't get why xmlDumpElementDecl accepts buf as first argument while 
it is an xmlHashScanner on an xmlElementTable - the same as I'm doing.

I won't dwell on it, but if you can explain it, I can sleep better ;)

> > Further investigation shows that xmlSchemaTypeDump in xmlschema.c indeed
> > has the argument order you list and swapping the arguments in my function
> > works.
>
>   Okay, normal. There is actually  3rd argument passed if you look at the
> declaration of xmlHashScanner() in libxml/hash.h

Yes - the name associated. I suppose that's the name in the _xmlHashEntry 
struct, and judging from xmlAddElementDecl that would be identical to 
xmlDtdElement->name.

-- 
Melvyn

Attachment: pgpJDYwGJiye3.pgp
Description: signature