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Re: [perl #130038] Builtin variable for loop index in foreach

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Dave Mitchell
November 9, 2016 09:44
Re: [perl #130038] Builtin variable for loop index in foreach
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On Tue, Nov 08, 2016 at 10:35:07AM +0000, Ed Avis wrote:
> Dave Mitchell wrote:
> >For ranges, e.g. (1..10) and ('a'..'z'), it only records the current value and the last value.
> But for numeric ranges, if you know the current value it is just a subtraction to find its index.

No, at the point where you have iterated  'for (11..20) {}' say, 7 times,
exactly two values are currently stored: 17 and 20. There is no way (in
general) to deduce that value '7' from that. Extra bookkeeping of one form
or another would need to be added.

A walk of a thousand miles begins with a single step...
then continues for another 1,999,999 or so.

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