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

Henning Thielemann lemming at henning-thielemann.de
Wed Sep 8 18:43:29 EDT 2010


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.

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


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