Re: [Haskell-cafe] Re: [m..n] question

On 2008 Sep 22, at 5:46, Jon Fairbairn wrote:

"Richard A. O'Keefe" writes:

...

It is being claimed that the reason for this is that "exceptions are problematic" in Hasell, so the Haskell designers went out of their way to make this function total whether it made sense or not.

I'm pretty sure that's not true. I'd like to be able to say "I know, I was there", but although I was there it was so long ago that my memory isn't clear. But it's clearly the

I would say it's more a matter of Haskell programmers thinking partial functions are evil as a general (mathematical) principle. And the claimant above is thinking of needing to catch exceptions in IO, and probably comes from the school of programming that says that invalid values should raise exceptions. Which sounds like a good idea until you see how often people do try {mumble()} catch {} or similar. (Go look at some Java programs; Java goes even farther with that idea and requires programmers to declare the exceptions they can throw, so many programmers shortcircuit the exceptions away to avoid having to deal with it.) -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allbery@kf8nh.com system administrator [openafs,heimdal,too many hats] allbery@ece.cmu.edu electrical and computer engineering, carnegie mellon university KF8NH