New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade!

Kiuhnm kiuhnm03.4t.yahoo.it
Mon Mar 12 09:05:54 EDT 2012


On 3/12/2012 12:27, Albert van der Horst wrote:
> Interestingly in mathematics associative means that it doesn't matter
> whether you use (a.b).c or a.(b.c).
> Using xxx-associativity to indicate that it *does* matter is
> a bit perverse, but the Perl people are not to blame if they use
> a term in their usual sense.

You may see it this way:
Def1. An operator +:SxS->S is left-associative iff
   a+b+c = (a+b)+c for all a,b,c in S.
Def2. An operator +:SxS->S is right-associative iff
   a+b+c = a+(b+c) for all a,b,c in S.
Def3. An operator +:SxS->S is associative iff it is both left and 
right-associative.

Kiuhnm



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