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Re: reduce metaoperator on an empty list

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Rod Adams
May 18, 2005 20:08
Re: reduce metaoperator on an empty list
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Rob Kinyon wrote:

>On 5/18/05, Stuart Cook <> wrote:
>>To summarise what I think everyone is saying, []-reducing an empty
>>list yields either:
>>1) undef (which may or may not contain an exception), or
>>2) some unit/identity value that is a trait of the operator,
>>depending on whether or not people think (2) is actually a good idea.
>I would think that the Principle of Least Surprise points to (1),
>given that the standard explanation of the [+]@x is eval join( '+', @x
>) ...
$rod == none(@Larry), and therefore just because I think it should be 
that way, doesn't mean it is that way.

But the "eval join" way of looking at it does seem to be consistent with 
what I've seen discussed previously, and would provide a useful way to 
remember the effects of edge cases.

-- Rod Adams

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