Date: Sat, 8 Apr 89 21:21:48 EDT
From: Don Hopkins <don@brillig.umd.edu>
To: lwall@devvax.Jpl.Nasa.Gov
Cc: don@brillig.umd.edu
Subject: hypertext & perl

I finished the manual! Perl sounds fantastic -- very powerful!  I
can't wait to start messing around with it. I'd like to try out 3.0
when you've put socket support into it -- that I can really use! I may
have missed it in the Perl 2.0 manual, but will there be a way to wait
for input (ala select(2)) on a bunch of fd's, find out how many bytes
are available for reading on an fd without blocking, and accept
incoming connections so's ya kin write Perl servers? (I'd also like to
be able to frob pty's, and do various ioctl's. Or would you rather
have a higher level interface to that kind to stuff?)

Now what I'd *really* like would be a clean easy way to link in my own
libraries and call them from Perl, and to be able to call Perl
functions from my libraries. Instant extension language -- just add
heavy water (and palladium)! 

I'm working on a hypertext system for NeWS, called HyperTIES. It has a
hypertext markup language interpreter that reads "storyboard" text
files, expands macros and drives the formatter. The formatter uses
NeWS to display mouse sensative text and graphics. The buttons on the
screen can feed commands back into the interpreter, which calls the
index manager to look up and display definitions, follow links,
backtrack, etc... Pictures and buttons are very open ended -- they can
look or behave like whatever... Their bodies are stored in auxilary
files which can contain arbitrary chunks of code (PostScript, or some
other language, like Perl.) It would be an interesting experiment to
link Perl with HyperTIES, and make it so the interpreters can pass
expressions to each other, and get return values. Communicating with
an asynchronous Perl process over a socket would be very useful, but
I'm looking for a more intimate relationship than you can carry on
over a socket. I'd like to be able to access and manipulate the
HyperTIES data structures from Perl, to generate synthetic articles,
indices, summaries, outlines, search results, directory listings, utmp
listings, mail headers, etc... [Do you know how "magic dictionaries"
work in NeWS? i.e. objects that behave like PostScript dictionaries
(Perl associative arrays?), but have read&write accessor functions
that safely manipulate underlying C structures, with magical side
effects! (like changing the /Retained key of a canvas)] HyperTIES
could be used to display and manipulate regular old files in place, in
whatever format they're written, by using Perl to translate them into
HyperTIES markup language and munge them on the fly!

I believe that no one language is good for everything.  PostScript is
good at describing pictures and interactive graphics, the HyperTIES
markup language is good at describing formatted text and graphics, and
I think Perl's just the thing for parsing and processing files,
generating input for the the above interpreters, and dealing with
Unix!

	-Don


From: lwall@devvax.Jpl.Nasa.Gov (Larry Wall)
Subject: Re: perl
To: don@brillig.umd.edu  (Don Hopkins)
Date: Mon, 3 Apr 89 15:33:13 PDT

> Enclosed is a message about what I'd like to do with perl.  Do you
> think it's the right language in which to write "liaison" (a
> connection manager, process server, pumping station, whatever --
> described in the last paragraphs below)? I'd also want the server to
> doll out pty's, as well. Know of any work in that direction? (I think
> it could all be done with emacs, but that's too heavy handed a
> solution.  I'd rather just run one multi-window emacs at once, and
> make connections between it and various liaisons running on
> different machines, to take care of my remote editing urges.)

Perl 3.0 will be better than 2.0 for that, since it supports binary data
and will support sockets, as soon as I hack them in.

Larry