Xref: utzoo comp.lang.lisp:700 comp.lang.misc:1019
Path: utzoo!mnetor!uunet!mcvax!enea!sommar
From: sommar@enea.se (Erland Sommarskog)
Newsgroups: comp.lang.lisp,comp.lang.misc
Subject: Re: Hierarchical Browsers
Message-ID: <2668@enea.se>
Date: 31 Jan 88 16:23:37 GMT
References: <747@zippy.eecs.umich.edu>
Reply-To: sommar@enea.UUCP(Erland Sommarskog)
Followup-To: comp.lang.misc
Organization: ENEA DATA AB, Sweden
Lines: 40


What I'm going to tell you about is probably a little aside of
what you're asking for, but it may be of interest to you anyway.
My apologies if it's not.

EXCO is not a viewer, but a fully-fledged editor, on the other
hand it is not syntax-directed. It is hierarchical, which is
why I bring it up.

In EXCO a line can either be a header line or a bottom line.
When you read in a file, you will only see the header lines.
You can expand such a line, to find new header lines or bottom
lines. When writing source code you typically write the pseudo-
code first and make those lines header lines, hiding one or
more source lines. You can of course work the other way. Write
a chunk of code see that it's getting too volumious and decide
to hide part of it.

You may wonder, "Hey what happens with those header lines when
I compile?". Well, EXCO introduces a new step in compile-link
chain, you must extract the source code first, but that's
is a relatively swift operation. Yes, the EXCO world has tools
for that.

I have been using EXCO for some years and it's quite nice. 
However, I feel the great advantage is when writing documents. 
EXUT, the related formatter uses the hierachical information 
for the chapter division. It saves from many obscure commands
a la nroff.

EXCO is not in the public domain. It is available on VMS and MS-DOS. 
For Unix it is currently only available for Sun. 

Write me if you want more info. No, neither I nor my employer have any
commercial interests in EXCO.
-- 
Erland Sommarskog       
ENEA Data, Stockholm        "Will you remember president Reagan
sommar@enea.UUCP             will you rememeber all the bills we'll have to pay
                             or even yesterday, tomorrow?" - David Bowie