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.Re: take a sequence of numbers 2 at a time, print numbers and their product?

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Lieven Marchand wrote:

> (Bob Felts) writes:
> 
> > Kaz Kylheku <kkylh...@gmail.com> wrote:
> >
> >> On Dec 27, 2:34 pm, "livingcosmos.org" <metap...@gmail.com> wrote:
> >> > How would you take a sequence of numbers in groups of 2 and print out
> >> > the numbers and their product?
> >> >
> > [...]
> >> 
> >> It's perhaps more useful to collect the results than print.
> >> 
> >> State machine approach:
> >> 
> >> (loop for x across nums
> >>       with acc
> >>       if (null acc) do
> >>         (setf acc x)
> >>       else
> >>         collect (* x acc) and do
> >>         (setf acc nil))
> >
> > Why not just:
> >
> >   (loop
> >            for x on nums by #'cddr
> >            collect (* (first x) (second x)))
> >
> >
> > The original problem might then be:
> >
> >   (loop
> >            for x on nums by #'cddr
> >            for a = (first x) and b = (second x)
> >            do
> >            (format t "~A * ~A = ~A~%" a b (* a b)))
> 
> You can let loop do the destructuring:
> 
> (loop for (a b nil) on nums by #'cddr ...)

Ruby:

[0,2,4,5,7,8].each_slice(2){|a,b| puts "#{a} * #{b} = #{a*b}"}

 ===>
0 * 2 = 0
4 * 5 = 20
7 * 8 = 56

In Forth?

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.Re: take a sequence of numbers 2 at a time, print numbers and their  product? "Robert L." <No_spamming@noWhere_7073.org> - 2017-01-23 04:36 +0000

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