On Wed, May 26, 2010 at 7:30 PM, Dario Teixeira
<darioteixeira@yahoo.com> wrote:
Hi,
> What experience does people have to using alternatives to exceptions,
> such as option types or exception monads? Does use of third part
> libraries that still throws exceptions make such approaches hard to use?
> Performance wise it seems to be comparable to catching exceptions or
> matching for options, so I guess the difference be might a question of
> programming style?
Partly yes, though I would say that in Ocaml it is tempting to use
exceptions beyond what is reasonable, because they are so cheap and
convenient. As you noted, this can lead to trouble at runtime, which
is why some libraries discourage the "exceptional style", preferring
option types and forcing users to invoke functions suffixed by "_exc"
if they really want to use the exception-based version.
Personally, I think the litmus test hinges on whether the supposedly
exceptional situation is truly worthy of the name. If it's a common
occurrence, perhaps one should reconsider the use of an "exception".
Without meaning to start an holy war, let me just add that even on
the Stdlib there are functions (such as Map.S.find) that raise an
exception but which should perhaps return an option type.
Btw, you didn't mention it explicitly in your message, but I trust you
are familiar with "Catch me if you can"? [1]
I have just read about it, not tested it yet. Do you have any experience using this library, especially together with other libraries that also provides syntax extension?