Subject: Re: things about grouping
From: Ihe Onwuka <ihe.onwuka@xxxxxxxxx>
Date: Thu, 29 Nov 2012 21:47:37 +0000
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On Thu, Nov 29, 2012 at 4:39 PM, Michael Kay <mike@xxxxxxxxxxxx> wrote:
>>Why do I have to write for $i in (1 to n) return "$1" instead of (1 to
>> n)/"$1!
>
> Because there were people on the working group who could not stomach the
> idea of having the expression 10/2 return 2.
>
One could have distinguished the sequence consisting solely of the
number 10 from the number 10 which with the existing syntax would have
gotten you the slightly less objectionable (10)/2.
One could have followed the lead of set theory, {10} is a set, 10 is
an integer, or the convention of functional programming languages of
using square brackets for lists/sequences. The other aspect of this is
the semantics of the symbol / which is pregnant with meaning from the
mathematical domain - a situation exacerbated by the fact that the
other operands in the expression happen to be numbers.
I have no idea how much mileage one gets from interpreting 10 as a
singleton sequence but it would seem that the tradeoff for doing so
was compositionality and I would have needed to see alot of miles to
have made that bargain.
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