[Haskell-cafe] ANNOUNCE: AbortT-transformers version 1.0

Colin Paul Adams colin at colina.demon.co.uk
Thu Sep 9 01:07:06 EDT 2010

>>>>> "Henning" == Henning Thielemann <lemming at henning-thielemann.de> writes:

    Henning> On Wed, 8 Sep 2010, Gregory Crosswhite wrote:

> ExceptionT is a different matter because it handles "fail" as an
    >> uncaught error and places no restrictions on the error type, so
    >> one could implement the same functionality as AbortT by using
    >> ExceptionalT and requiring the end result be a monadic value of
    >> type "ExceptionalT e m e", where the exception and result types
    >> are the same.  However, I believe that it is better to have the
    >> AbortT functionality available as a separate simple library
    >> specialized for this purpose than to have its functionality
    >> buried inside a more general library that is really intended to
    >> be used for a different purpose.

    Henning> If we get rid of the notion of an exception as being
    Henning> something bad, and instead consider an exception as being
    Henning> early exit for whatever reason, I see no problem. E.g. you
    Henning> may well use an exception to terminate a successful search,
    Henning> returning the search result as exception value.

So where is the exceptional nature? Is a successful conclusion to a
search so exceptional?

It seems to me that you want to get rid of the notion of an exception as
something exceptional, in which case it would be better to give it a
different name.
Colin Adams
Preston Lancashire
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