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Re: Order of evaluation of terms (was peephole optimiser could prune more dead code)

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July 15, 2010 15:58
Re: Order of evaluation of terms (was peephole optimiser could prune more dead code)
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On 16 July 2010 00:55, Ben Morrow <> wrote:
> Quoth (demerphq):
>> On 15 July 2010 21:42, Zefram <> wrote:
>> >>                                         And because terms are left
>> >>associative,
>> >
>> > It's meaningless to speak of the associativity of a term (atomic
>> > expression).  The concept of associativity only applies to infix
>> > operators.  There is in fact a doc bug here, in that perlop ascribes
>> > associativity to terms and to "list operators (leftward)" (a list operator
>> > expression viewed from the left, from where it looks like a term).
>> Well, i think there is an ironic misparse involved, and not so much a
>> doc bug. The docs say:
>>        Terms and List Operators (Leftward)
>> but this is in a /section heading/. Looking at the other section
>> headings I seems that none of them mention anything about
>> associativity. So I think that the above should not be parsed as:
>> (Terms and List Operators) (Leftward)
>> but in fact
>> (Terms) and (List Operators (Leftward))
>> Or alternatively:
>> Terms and Leftward List Operators.
>> That is, the "(Leftward)" is meant to be a property of List Operators,
>> but not of Terms.
>> The only problem with this interpretation is that there are no "right
>> associative" list operators, but perhaps the author was being
>> conservative and assumed that maybe one day there would be...
> This is more-or-less correct, but the contrast is with
>    List Operators (Rightward)
> much further down (the point being that list operators have different
> precedence viewed from the left and from the right).

Sigh. I looked for that, and missed it. Thanks Ben.


perl -Mre=debug -e "/just|another|perl|hacker/"

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