[comp.software-eng] Editing languages

gbt@sequoia.cray.com (Greg Titus) (06/21/91)

In article <1991Jun21.015801.25167@netcom.COM> jls@netcom.COM (Jim Showalter) writes:
>
> [deleted short reuse discussion]
>
>The Rational text editor can, believe it or not, be invoked programmatically
>because all of its operations are exported out of a package called Editor,
>so you can do stuff like:
>
>    Editor.Cursor.Up (Lines => 4);
>    Editor.Char.Insert_String ("This is done by magic.");
>    etc.
>
>Comes in handy sometimes, and is great for automating demos.

Somewhat off the subject, but this brought to mind the topic of
editing languages ...

An editing language is a wonderful thing to have in your
toolbox.  Not having to worry about the screen manipulation and
buffering and so on saves boatloads of implementation time.  I
recall writing TECO code for quite a few small interactive data
entry/editing tools in the past, and the Eel language from
Epsilon is highly useful for this sort of thing as well.

TECO was invented at MIT back in the 60's.  I doubt you could
find a running TECO any more, but it was widely available (from
DECUS) on DEC PDP series machines as recently as 1980 at least.
The original EMACS was written in TECO; in fact, the name stands
for Editing MACroS, since EMACS was just a set of TECO macros
for keeping the screen continuously updated.  If you remember
TECO, you're a Pretty Old Programmer (Not Real Old, but Pretty
Old).  Or maybe you just started young ...   ;-)

Epsilon's Eel is also used to implement EMACS, but for MS-DOS
machines.  Eel is mostly C, but with some things not essential
to editing left out and some others that are essential added.
You get most of the Eel source for Epsilon's EMACS when you buy
it, so you can add to or modify the editor's functionality.  The
nice thing is that you can also implement standalone-ish
programs with it.

Jim and I largely agree about Ada's strengths for design and
implementation, I think.  Nevertheless, if you're a fan of
computer languages, ya gotta love the oddities among them, like
editing languages.  And I didn't even mention fun things like
SNOBOL, APL, ...

Speaking of such, my own favorite language name is "PLITS", for
"Programming Language In The Sky".  I heard of this a long time
ago, but I don't know much about it other than the name.  I
believe that it was a research language, and that there was only
one compiler ever built for it.  Can anybody out there enlighten
us about PLITS?

greg
--
--------------------------------------------------------------
Greg Titus (gbt@zia.cray.com)             Compiler Group (Ada)
Cray Research, Inc.                               Santa Fe, NM
Opinions expressed herein (such as they are) are purely my own.

pat@rock.opus (pat gioannini) (06/22/91)

Does anyone know of a PD language written in ada which
would be suitable for display control.

What I am thinking of is a language simular to emacs lisp
interperter running a user program to display data.  The 
data will be comming from another Ada task though procedure
calls ( so it would be nice if the interpter was written in Ada ).

                 |--------------------------------------
                 |                                     |
                 |     Ada application                 |
                 |                                     |
                 |                                     |
                 |                                     |
                 | ---------------|     |-----------|  |
data ----------> | |collect data  |---> | Interpter |  | 
                 | |  task        |     | output to |  |
                 | |              |     |  screen   |  |
                 | |--------------|     |-----------|  |
                 |                          ^          |
                 |                          |          |
                 | |--------------|         |          |
                 | | other tasks  |         |          |
                 | |              |         |          |
                 | |              |         |          |
                 | |              |         |          |
                 | |              |         |          |
                 | |--------------|         |          |
                 |                          |          |
                 |--------------------------------------
                                            ^
                                            |
                                            |
                 |--------------------------------------
                 |                                     |
                 | User display program written in     |
                 | the interperted language            |
                 |--------------------------------------

wex@cs.ULowell.EDU (Paul Wexelblat) (06/22/91)

There is a teco newsgroup; therein are listings for teco in EMACS macros;
EMACS was, of course, originally a bunch of teco macros.

	...Wex (PDP-1 teco hacker (amongst other things))