Re: [Gnu-arch-users] Re: User-defined "macro" commands

[Dustin Sallings]

On Dec 15, 2003, at 8:47, Tom Lord wrote:

> 1) What's with all the aliases?
>
>    They serve two purposes:
>
>    a) A way to rename commands in successive releases without abrupt
>       transitions.
>
>       We don't currently use the deprecated command flag this way, but
>       we certainly could: when a command is invoked by a deprecated
>       name, print a warning on stderr that the name will be going away
>       in a future release.

	I agree that this is obnoxious, but I think it's also necessary.  If 
something's going away, people should know about it.

>    b) A way to provide shared short-names and "alternative perspective"
>       names.

>   (Neither of those purposes would be well served by an extended
>   command mechanism.)

	This one I don't particularly agree with as it really just sounds like 
user preferences being applied globally.  Part of the problem is that 
it doesn't currently cover a great deal of options.  CVS, for example, 
has two aliases each for ``checkout,'' ``commit,'' and ``update.''  If 
we're going for short names, then it also might make sense to include 
CVS-compatible short names (co/ci/up) which would also help ease 
transition.

	``alternate perspective,'' really seems like a third thing.  To me, it 
seems like something that might, at some point, do something different. 
 It implies that one is thinking more of a high-level solution to a 
problem than a low-level typing efficiency thing.

> 2) How about the "extended command" thing?
>
>   For another thing, the "fork/exec approach to extensions" doesn't
>   provide much help to extension writers.   Providing such help seems
>   to me to be the bigger problem that needs solving than the problem
>   of "how do I turn `tla <unrecognized-command>' into a call to an
>   extension?

	I'm greatly looking forward to being able to write extensions in 
scheme, but there is something to be said for an ``anemic'' solution 
that is already written.

	I also get the point that it's possible to replace tla in my path with 
a shell script that emulates the alias functionality.

        Anyway, thanks.  Views are exchanged.  I'm getting back to work now.

--
Dustin Sallings