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Forum => Whither newLISP? => Topic started by: Sunburned Surveyor on November 30, 2005, 04:16:57 PM

Title: Searching elements in an association list...
Post by: Sunburned Surveyor on November 30, 2005, 04:16:57 PM
I would like to know if there is a function in NewLISP that will return all the elements of an association list based on the value of any of the lists members.



For example, I have the following list:



("fruit" "bannana" "pear" "apple" "plum" "grapes")

("vegatables" "lettuce" "celery" "cucumbers" "olives" "onions")

("junk food" "ice cream" "licorice" "chocolate bar" "carmel apple" "bubble gum")



I want to be able to retrieve the entire "junkfood" list by searching for any one of the elements. I believe the lookup and assoc functions only allow you to do this when using the first element in the association list.



Thanks for the help.



The Sunburned Surveyor
Title:
Post by: Sammo on November 30, 2005, 06:01:50 PM
Code Select
(set 'food-lists
'(
  ("fruit" "bannana" "pear" "apple" "plum" "grapes")
  ("vegatables" "lettuce" "celery" "cucumbers" "olives" "onions")
  ("junk food" "ice cream" "licorice" "chocolate bar" "carmel apple" "bubble gum")
))

(define (magoo findme a-list)
  (a-list ((ref findme a-list) 0)) )Then



> (magoo "chocolate bar" food-lists)

("junk food" "ice cream" "licorice" "chocolate bar" "carmel apple" "bubble gum")
Title:
Post by: Sammo on December 04, 2005, 02:09:11 PM
Improved so that (magoo "no such food" food-lists) returns nil.
Code Select
(define (magoo key aList)
  (let
    ( vec (ref key aList) )
  ;body of let
    (and vec (aList (vec 0)) ) ))
> (magoo "no such food" food-lists)

nil

> (magoo "celery" food-lists)

("vegatables" "lettuce" "celery" "cucumbers" "olives" "onions")
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