Re: Improving Emacs' iCalendar support

[Adam Porter]

Hi Richard,

I don't have much to add to what's been said, but my first thought is 
that a robust iCal library would probably be most useful for importing 
and exporting between the iCal format, obviously.  So I'd suggest that 
its API should help with transforming iCal data into other formats, 
probably by converting it into a simple Lisp data structure that other 
libraries could work with.  And then, it should also provide a function 
to transform that data structure back into an iCal file.

Also, it would be good if it were designed to be extensible in case the 
standards receive updates, or in case vendor-specific functionality is 
needed by users.

So I'd suggest looking at the existing Emacs/Org applications that use 
iCal, and designing your API so that such applications would find it 
easy to use (not that it should directly imitate what already exists, 
unless such APIs are already ideal).

Finally, I'd suggest that you consider using structs as the primary 
internal data structure, because they provide setter and accessor 
functions, which are helpful to developers (e.g. they help catch some 
mistakes at compilation time).  If you do, I've found it helpful to 
define an "etc" slot in various structs to which an alist or plist can 
be attached, which provides the ability for the structs to carry 
additional data that wasn't foreseen during its design.

--Adam