[Xcb] GSoC 2009: XKB and XI2 support

[Josh Triplett]

On Thu, Sep 17, 2009 at 11:03:12AM -0400, Peter Harris wrote:
> Josh Triplett wrote:
> > I understand and agree with your statement that every bit of syntax
> > creates work for every user of the XML, but I don't see how <replyof>
> > requires any more work from a streamy processor than <struct> does.  Can
> > you clarify?
> 
> Every struct is used eventually, so a streamy processor can simply emit
> a struct handler when it sees the struct and forget about it. There is
> no way to foresee which (very few) request fields may be copied at a
> later date.
> 
> So the streamy processor must:
>  0) store an incredible amount of state (making it non-streamy)
>  1) emit every request field as a separate function, effectively
> treating every field as a single-entry struct. This makes the generated
> code ugly (and maybe inefficient, depending on the compiler/interpreter)
> or
>  2) emit every field twice (once in-line in the original request, and
> once as a separate handler in case some reply ever uses it), making the
> output ugly (and maybe bloated, depending on the compiler/interpreter)

Fair enough.

(I also admit to a bit of confusion between "streamy" processing of the
X protocol stream and "streamy" processing of the XML.  Why do you want
to do the latter?)

- Josh Triplett