Groups > comp.lang.forth > #20376

Re: SP-Forth: reduce or fold a list

From	"WJ" <w_a_x_man@yahoo.com>
Newsgroups	comp.lang.forth
Subject	Re: SP-Forth: reduce or fold a list
Date	2013-03-06 23:50 +0000
Organization	A noiseless patient Spider
Message-ID	<kh8knb$19b$1@dont-email.me> (permalink)
References	<kh80t5$ec8$1@dont-email.me> <kh8j7q$q72$1@dont-email.me>

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WJ wrote:

> WJ wrote:
> 
> > REQUIRE list-all ~ygrek/lib/list/all.f
> > list ALSO!
> > REQUIRE RANDOMIZE ~af/lib/random.f
> > 
> > 0 VALUE biglist
> > 
> > : reduce-test
> >   \ Build list of 9999 random integers.
> >   %[ 9999 0 DO  5000 CHOOSE %  LOOP ]%
> >   TO biglist
> >   S" Length of list is " TYPE  biglist length .
> >   \ Sum the list.
> >   0 biglist ['] + iter
> >   CR S" Sum of list is " TYPE  .
> >   biglist free
> > ;
> > 
> > reduce-test
> > Length of list is 9999
> > Sum of list is 25009246  Ok
> 
> 
> Factor:
> 
> USING: random ; 
> 
> 9999 iota [ drop 5000 random ] map
> "Length of list is " write dup length .
> 0 [ + ] reduce
> "Sum of list is " write .
> 
> Length of list is 9999
> Sum of list is 25051634

"reduce" isn't even needed; one can simply use "each"
(equivalent to "iter" in the SP-Forth code):

0 { 1 3 5 7 } [ + ] each .
16

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Thread

SP-Forth: reduce or fold a list "WJ" <w_a_x_man@yahoo.com> - 2013-03-06 18:11 +0000
  Re: SP-Forth: reduce or fold a list "Charles Childers" <crc@retroforth.org> - 2013-03-06 16:42 -0500
  Re: SP-Forth: reduce or fold a list "WJ" <w_a_x_man@yahoo.com> - 2013-03-06 23:24 +0000
    Re: SP-Forth: reduce or fold a list "WJ" <w_a_x_man@yahoo.com> - 2013-03-06 23:50 +0000

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