Re: [9fans] Limbo Tk FAQ?

[Lucio De Re <lucio@proxima.alt.za>]

On Fri, May 25, 2001 at 10:59:48AM +0100, rog@vitanuova.com wrote:
> 
> i wouldn't like to do this sort of stuff in tcl.  limbo just makes it
> so simple.
> 
Tcl with channels would do well, too :-)  (Oops, I hope I'm not
speaking through my nose here, I've only given the code a brief
glimpse, looking forward to look at it in more detail later).

> that said, i think there is room for some sort of expandability in
> limbo/tk, not via tcl, i think but perhaps via some sort of
> channel/module/device interface.
> 
I'm sure I'm sounding like an old hag peddling Tcl, but what appeals
to me about Tcl is that one can construct composite commands, in
effect interpretive language constructs) that more naturally describe
the activities of a user or a class of users of a particular
application.  Tk is very much an example of such an extension, in
this case to Tcl itself, but also to any application that used Tcl
as its command language in the first place.

And adding "filesystems" semantics to Tcl may be an interesting
challenge, too.  It certainly could make very healthy use of the
plumber, in a multi-threaded environment.

As an example (not necessarily a good one) I knocked together a
very small shell to handle a particular aspect of a postgresql
database, using "expect" so that the user could get the benefits
of the Tcl interpreter right at the command line level and still
clean up when they terminated (there may well have been a better
way, but Tcl has grown far beyond its documentation and reading
source is not my idea of keeping up with creeping featurism).

What I was aiming at, though, was the ability to build a few, simple
to use underlying constructs and teach the users how to construct
more complex ones for their purposes, often on the fly.  More
permanent, or often used commands could be included in the prologue,
euither globally or by being included in a particular instance.
In that respect, Tcl is a command line shell, and a very powerful
one, at that.  With default parameters and a sensible prologue and
epilogue, I could provide a secure environment for less savvy, but
trustworthy users.

> i'm sorry, i'm off topic.
> 
We often are, on this mailing list, but the nature of Plan 9 is to
encourage this, not treat it as if it was an unsightly wart.

++L