[slime-devel] giving reasons for RPC aborts

[Taylor R Campbell]

(I asked about this a year ago, but must have forgotten about it.)

There are many cases where a user invoked a command that doesn't make
any sense, so the RPC can't complete with a meaningful answer, but it
would also be overkill to throw the user into a debugger.  It would be
nice to abort the RPC with a message to the user, such as `Package
does not exist' for `slime-repl-set-package' or `Undefined function'
for `slime-disassemble-symbol'.  It looks like there was once a time
when a message could be supplied with a :ABORT result from an RPC, and
there are some vestigial remnants of support for it -- `slime-rex'
forms with (:ABORT &OPTIONAL REASON), and indeed the documentation of
`slime-rex' says that the reason is not optinoal --, but there are
many other uses that prohibit a reason from being supplied.

Is there a good reason for :ABORT responses not to have an optional
message associated with them, or would a patch be welcomed for all of
the uses of `slime-rex' to consistently accept an optional message?