Re: Calling XCMDs from MCL

[bill@cambridge.apple.com (Bill St. Clair)]

At  8:36 PM 10/18/93 +0000, Mark Guzdial wrote:
>I've been working in HyperCard for several years, and now that I'm
>trying to move to MCL, I'd like to try using some of the XCMDs and
>XFCNs that I've collected and built.  I see the HyperXCMD.lisp file in
>Library:Interfaces, which looks like it could support even the
>HyperCard 2.x XCMD interface, but it's not clear how to call an XCMD
>or XFCN using these structures.  I've downloaded xcmd.lisp from
>cambridge.apple.com, but it seems to redefine some of the structures
>of HyperXCmd.lisp and doesn't support all of the HyperCard XCMD
>interface.
>
>Can someone explain the difference to an MCL novice between
>HyperXCmd.lisp and XCMD.lisp?  How DOES one call an XCMD or XFCN from
>MCL?

I didn't see any public responses yet, so...

"HyperXcmd.lisp" in the interfaces folder is an include file for writers
of XCMDs. We included it in the MCL distribution only for completeness.
"xcmd.lisp" from camrbridge.apple.com is the only way I know of to
call XCMD's and XFCN's from MCL. Its documentation says that it is
incomplete. I believe it signals an error when it gets a callback that
is not implemented. This gives you enough information to implement
the ones that your XCMD's need. A bigger problem may be that "xcmd.lisp"
was written for HyperCard 1.x. I don't know if it works for HyperCard
2.x, which I believe has a larger set of callbacks.