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Forum => newLISP in the real world => Topic started by: Tim Johnson on May 03, 2010, 02:56:46 PM

Title: accessing a list number by a symbol for a list
Post by: Tim Johnson on May 03, 2010, 02:56:46 PM
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> (set 'record '(("name" "Tim")(age 61)))  
(("name" "Tim") (age 61))
> (set 'indices '(1 0))
(1 0)
> (record indices)
age    ;; correct
> (set 'ndxs '(a b))
(a b)
> (record ndxs)
ERR: value expected :  ;; duh!

So how may I 'bind' the values in 'ndxs to the implicit indexing of 'record?

I'm hoping there is a tie-in to the previous question, I.E. I might want to

index 'record by a slice of the values in 'ndxs also.

thanks

tim
Title: Re: accessing a list number by a symbol for a list
Post by: Sammo on May 03, 2010, 06:19:17 PM
Would this work?
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> (set 'record '(("name" "Tim")(age 61)))
> (set 'ndxs '(a b))
> (set 'a 1 'b 0)
> (record (map eval ndxs))
age
Title: Re: accessing a list number by a symbol for a list
Post by: Tim Johnson on May 03, 2010, 07:13:36 PM
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> (record (map eval ndxs))

Sure does. 'map threw me for a bit of a loop because
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(record (map (eval ndxs)))
generates an error.

thanks.
Title: Re: accessing a list number by a symbol for a list
Post by: Tim Johnson on May 04, 2010, 08:34:26 AM
And we use 'slice as in
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(slice (map eval ndxs) 1)

Implicit indexing is great feature. I might add to the documentation of

this subject something of the subject here.



I.E. use of symbols, etc.



:)But then, I'm a real noob when it comes to the functional programming paradigm.
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