On Tue, Jan 20, 2015 at 9:12 PM, Uri Guttman <u...@stemsystems.com> wrote:
> On 01/20/2015 11:28 PM, Charles DeRykus wrote:
>>>
>>> ...
>>> or something odd
>>> my $contents = do { local $/; map { chomp } <HANDLE> };
>>>
>> I'm afraid this, while appealing, in my testing generates an
>> incorrect result, ie, 1.
>>
>> <SPECULATION>
>> What happens I suspect is that the map{ } is in void context, not the
>> scalar context of the outer do{}. Remember parsers are not as
>> all-knowing as we'd like them to be. Therefore map churns merrily
>> along and tosses its intermediate results until the final line.
>> Only at that point does parser wake up and say "Aha, the do{ } wants
>> scalar context so my final map{} value needs
>> to be returned in scalar context. So here's what map{} does in
>> scalar context. From 'perldoc -f map' :
>
>
> the map call is in scalar, not void context. the do block returns the value
> of the last statement and that is being assigned to a scalar. context is
> propogated in (like with subs) so map is in scalar context. regardless,
> using map with no return value is never a good idea as it subverts its
> purpose and misleads the reader of the code.
>
Yes, I understand. I was speculating more about when the propagation occurred,
i.e, early or late. By "void" context, I erred and meant that the
actual map results
were themselves tossed into the "void". Only the count mattered.
Clearly though, the chomp occurs only on a single string anyway due to
the $/ setting
so it's not the intended result..
--
Charles DeRykus
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