Path: utzoo!utgpu!watmath!clyde!mcdchg!motcoh!osu-cis!tut.cis.ohio-state.edu!mailrus!ames!amdcad!sun!pitstop!sundc!seismo!uunet!mcvax!enea!sommar
From: sommar@enea.se (Erland Sommarskog)
Newsgroups: comp.editors
Subject: Re: Editor extensibility
Message-ID: <4033@enea.se>
Date: 29 Oct 88 20:25:40 GMT
Organization: ENEA DATA AB, Sweden
Lines: 31

Ian Moor (iwm@asun2.ic.ac.uk) writes:
>The TPU system on VMS is extensible - DEC supply an EDT emulation and the EVE
>interface written in TPU -- I think the LSE (language sensitive editor) that 
>DEC sells is also written in TPU. There was a good emulation of VI in TPU 
>posted recently. TPU looks a bit like MODULA2/ALGOL68/ADA it has keywords
>instead of functions :- 
>  IF x THEN y ELSE z ENDIF instead of (if x y z)
>I have seen more and better documentation on using TPU than Emacs lisp (hint).

Ah, glad to see someone else mentioning TPU! I have written my customized
editor with both Emacs (Unipress) and TPU, and clearly TPU is my favourite.
There are two main reasons for this:
* TPU has primitives that let you position the cursor anywhere in the
  window, no matter is there is any text or not. (I.e. if I am in 
  column 50 and goes one line up, I still want to be in column 50 even
  this line is only 20 characters long.)
* Emacs is so goddamm slow!
Another thing which appeals to me is that TPU has much less of
built-in functions; they are more of basic primitives, which you
can use as you like. E.g. I have no use for the built-in move-by-
word functions in Emacs, since I define a word differently. TPU
doesn't have any word concept at all.

It should be added that TPU has many flaws too. I hope to see some
of them corrected when I get to play with VMS 5.0.

As for layered software using TPU: DEC's VAXNotes is also TPU-based.
-- 
Erland Sommarskog            
ENEA Data, Stockholm         
sommar@enea.UUCP