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Forum => newLISP in the real world => Topic started by: HPW on October 24, 2017, 12:47:37 PM

Title: Best way to slice a long list in sublists
Post by: HPW on October 24, 2017, 12:47:37 PM
Hello,



I have a long flat list of params parsed from a csv file.

For example it has for eample 49 items and I know that they are a mulitple of 7 elements.



What is the most elegant way to slice the list into a list with 7 sublists with each 7 items?

In a loop with (slice 0 7) and so on?



Regards

Hans-Peter
Title: Re: Best way to slice a long list in sublists
Post by: HPW on October 24, 2017, 01:33:32 PM
My current code:
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(setq counter 0)
(dotimes (xx (/(length slotlst)paramnumber))
(setq newlst (append newlst (list(slice slotlst counter paramnumber))))
(setq counter (+ counter paramnumber))
)
Title: Re: Best way to slice a long list in sublists
Post by: fdb on October 24, 2017, 03:22:06 PM
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(explode slotlist 7)

There are a *lot* of usefull functions standard in newlisp ;-)



And if there wasn't such a function i would write something like:


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(define (my-exp llst number)
  (if (empty? llst)
      '()
      (cons (0 number llst) (my-exp (number llst) number))))

Who doesn't like recursion and implicit indexing ! ;-)



Mvg

Ferry
Title: Re: Best way to slice a long list in sublists
Post by: HPW on October 25, 2017, 12:14:09 AM
Hello ferry,



Thanks a lot for the tip. I wasn't aware of that nice command.
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(explode slotlist paramnumber)

Works like a charm.


Quote
Who doesn't like recursion and implicit indexing ! ;-)

Jup, don't teach a old horse new tricks.

Working mainly in Autolisp let me often forget the nice things from newlisp. ;-)



Regards

Hans-Peter
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