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Re: Simple problem

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WJ wrote:

> WJ wrote:
> 
> > 
> > Given a list of strings, count the number of times each string
> > occurs.  Sort the result from most to least common.
> > 
> > Factor:
> > 
> > 
> > USING: locals ;
> > 
> > :: counts ( seq -- seq )
> >   H{ } clone :> table
> >   seq [ table inc-at ] each
> >   table >alist [ [ last ] bi@  swap  <=> ] sort
> >   dup .
> > ;
> > 
> > { "c" "c" "a" "b" "b" "c" } counts
> > 
> > { { "c" 3 } { "b" 2 } { "a" 1 } }
> 
> Made shorter by using >=< instead of <=>.
> 
> USING: locals ;
> 
> :: counts ( seq -- seq )
>   H{ } clone :> table
>   seq [ table inc-at ] each
>   table >alist [ [ last ] bi@  >=< ] sort
> ;
> 
> The doc. for <=> says:
> 
>   Compares two objects using an intrinsic linear order, for
>   example, the natural order for real numbers and lexicographic
>   order for strings.
> 
>   The output value is one of the following:
>     +lt+ - indicating that obj1 precedes obj2
>     +eq+ - indicating that obj1 is equal to obj2
>     +gt+ - indicating that obj1 follows obj2
> 
> The doc. for >=< says:
> 
>   Compares two objects using the <=> comparator and inverts the
>   output.

Ruby:

["c", "c", "a", "b", "b", "c"].group_by{|x| x}.map{|k,v| [k,v.size]}.
  sort_by{|k,v| -v}

    ==>[["c", 3], ["b", 2], ["a", 1]]

Can this be done in Forth? Or is Forth merely a stone-age toy?

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Re: Simple problem "WJ" <w_a_x_man@yahoo.com> - 2013-06-15 00:53 +0000
  Re: Simple problem visualforth@rocketmail.com - 2013-06-21 20:14 -0700
    Re: Simple problem glidedog@gmail.com - 2013-06-22 06:01 -0700
      Re: Simple problem rickman <gnuarm@gmail.com> - 2013-06-22 09:48 -0400
      Re: Simple problem Bernd Paysan <bernd.paysan@gmx.de> - 2013-06-22 22:55 +0200
        Re: Simple problem "Elizabeth D. Rather" <erather@forth.com> - 2013-06-22 11:47 -1000

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