Re: [pdf-devel] Error module: first lines

[gerel]

 > From: Behdad Esfahbod <address@hidden> Are you proposing these as part of
 > the error handling scheme for the library?  If yes, I'm strongly against
 > them.  Libraries should:
 > 
 >   - Be re-entrant.  That means, a global total-number-of-errors is useless.

I agree.

 >   - Not write anything on stdout/stderr unless explicitly asked to.  (this
 > can be relaxed to "Not write anything... if explicitly asked to", but I
 > prefer the former)
 >

Sure.

 >   - Not terminate the process unless explicitly asked to.  That means, no
 > abort on bad input.  No asserts as much as possible.  Debug builds are an
 > exception.
 >

The current API doesn't abort the process unless you tell it to, by giving the
"status" variable a value different than 0.

 >   - Be painlessly usable by multiple users in the same process.  That means,
 > things like "context" objects should be used that encapsulate everything a
 > user of the library needs, and allow for multiple contexts to co-exists.
 > This essentially requires all the above, no global total-number-of-errors, no
 > unwanted printout, and definitely no termination.
 > 
 > I highly recommend the error-reporting scheme used in cairo.  The way it
 > works is that each object retains its own error status (the error code of the
 > first encountered error in fact) and ignores any subsequent requests to the
 > object.  Errors are propagated from object to object, and can be queried for
 > by the user.  This lends itself quite well to language bindings that want to
 > throw exceptions for example, and is comfortable to use from C too, as you
 > can simply draw whatever you want (make as many function calls as you want)
 > and only query for error at the end.
 >

Can we write that scheme on top of the current API ?

Thank for your comments behdad.

-gerel