From mboxrd@z Thu Jan  1 00:00:00 1970
Message-Id: <200305091646.h49Gks501287@augusta.math.psu.edu>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] same functions everywhere
In-Reply-To: Your message of "Fri, 09 May 2003 14:21:25 BST."
             <622b8580ff4fa7e12cb655bf19694fe8@vitanuova.com>
From: Dan Cross <cross@math.psu.edu>
Date: Fri,  9 May 2003 12:46:54 -0400
Topicbox-Message-UUID: a5f30902-eacb-11e9-9e20-41e7f4b1d025

> exceptions are surprising things: they do not facilitate linear
> reading of the code; they should be kept for genuinely surprising
> conditions.

I think this kind of depends on the syntax.  I once saw a proposed syntax
for Limbo (due to  Michael Baldwin, inspired by Icon, perhaps) that I
thought was really great; it looked something like:

	thing = function(foo, bar, baz); ! { exception handler, note bang }

The ability to station an exception handler after a statement using
the bang syntax gave one the `feeling' of programming without exceptions,
but also allowed one to move the error handling to a potentially more
appropriate place.  You could write code like:

	if (a == SYMBOLIC_CONSTANT) {
		str := string arr;
		b := a / 2;
		mod = load Mod Mod->PATH;
	} ! { sys->print("Something bad happened.\n"); }

It was very unintrusive, and I liked it a lot.

	- Dan C.