[Haskell-cafe] Re: Use unsafePerformIO to catch Exception?
lemming at henning-thielemann.de
Fri Mar 27 21:01:38 EDT 2009
On Fri, 27 Mar 2009, Jason Dusek wrote:
> 2009/03/27 John Lato <jwlato at gmail.com>:
>> I could follow the rest of this, but I don't understand why
>> 'head' is necessary. Couldn't you always replace it with a
>> case statement, with undefined on  if necessary?
> How would that be any different from head?
The psychological advantage is, that you had to do something with the case
 and programmers hopefully hesitate more to write 'error' than to write
'head'. :-) Practically, if you have no better idea than writing 'error',
you would write an error message that is more specific than "head: empty
list", which makes debugging easier.
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