🚀 go-pugleaf

Ari Lukumies <aril@cmt.lpr.mail.carel.fi> writes:

> >                 format('!', bangcvt);
> > 
> >                 /* do something which can generate an error */
> >                 fprintf(stderr, "%s: %!\n", "open failed");
> >         }

>Given the above, how about calls like (well, not a pretty one, but you get the 
>idea...):

>	fprintf(stderr, "%-*.2!", something);


Yes, it seems that the format call back function (bangcvt) should take
a number of flags (leading 0/- found, precision, maximum width) and
a generic way to make the user defined format specifier output characters,
as it can be called from functions like "snprintf", which limit the output.
Passing a buffer to but the output in doesn't strike me as sufficient;
if "bangcvt" can have unlimited output, it must be possible for the
mechanism to cater for that.

And, of course, you want a input conversion as well :-)

So instead of:

> >         int bangcvt(va_list *ap, char *s, int len, fmtspec *f) {

You'd get something more like:

    bangcvt (va_list *ap, int flags, int width, int precision,
	char fmt, int (*putit)(char c, void *output), void *output)

(Where you call "putit" for each character of output with *output
as magic for the call back)

Casper
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Statements on Sun products included here are not gospel and may
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