[Haskell-cafe] New Hackage category: Error Handling

Henning Thielemann lemming at henning-thielemann.de
Sat Dec 5 17:55:35 EST 2009

On Sun, 6 Dec 2009, Michael Snoyman wrote:

> I think there are plenty of examples like web servers. A text editor with plugins? I
> don't want to lose three hours worth of work just because some plugin wasn't written
> correctly. For many classes of programs, the distinction between error and exception is
> not only blurred, it's fully irrelevant. Harping on people every time they use error in
> the "wrong" sense seems unhelpful.
> Hope my commenting on this subject doesn't become my own form of *pedantry*.

In an earlier thread I have explained that one can consider a software 
architecture as divided into levels. What is an error in one level (text 
editor plugin, web server thread, operating system process) is an 
exception in the next higher level (text editor, web server, shell 
respectively). This doesn't reduce the importance to distinguish between 
errors and exceptions within one level. All approaches so far that I have 
seen in Haskell just mix exceptions and errors in an arbitrary way.

More information about the Haskell-Cafe mailing list