Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!zaphod.mps.ohio-state.edu!usc!jarthur!mti!adrian
From: adrian@mti.mti.com (Adrian McCarthy)
Newsgroups: comp.lang.c
Subject: Re: Managing error strings in C
Message-ID: <1320@mti.mti.com>
Date: 21 Jan 91 19:33:54 GMT
References: <1991Jan10.122227@lotus.lotus.com> <620@necssd.NEC.COM> <1991Jan19.163652.9203@hemel.bull.co.uk> <2271@wzv.win.tue.nl>
Reply-To: adrian@mti.UUCP (Adrian McCarthy)
Organization: Micro Technology, Anaheim, CA
Lines: 24

In article <2271@wzv.win.tue.nl> wietse@wzv.win.tue.nl (Wietse Venema) writes:
>Error numbers, file names, line numbers etc. are often available as
>global variables. These do not need to be passed to the message
>formatter at all, if it understands format strings that look like:
>
>	"Error %{error_number} on line %{line_number}"
>
>and consults the corresponding global variables to do %{...} expansion.

This has its good and bad sides.

Good:  It's efficient and solves the problem at hand.

Bad:  If the message printer has to know about global variables specific to
a particular program, it can't be re-used in another without modification.

(This could be solved by using a structure that maps names used in the error
messages to global variables used in the particular program.  Handling the
various types could be tricky.)

Bad:  It tempts programmers to put too much information into global variables
which renders the program difficult to modify and maintain.

Aid.  (adrian@gonzo.mti.com)