using ref data

[joejoe]

The ref and ref-all functions bring back an address or list of addresses.



As cormullion wrote in the nL wikibook:

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(ref-all "Brian Eno" itunes-data)
;-> ((0 2 14 528 6 1) (0 2 16 3186 6 1) (0 2 16 3226 6 1))

What would be the best way to get that data instead of the numerical addresses?



Essentially, once I find the address is (0 2 14 528 6 1), how best would I get what it actually is, not the address?



So how best to get (0 2 16 3186 6 1) data?



Thank you!

[newBert]

Sorry, I don't have time to answer from a concrete example that should first be created. But I think there are some interesting tracks in the wikibook, especially https://en.wikibooks.org/wiki/Introduction_to_newLISP/Lists#Find_and_replace_matching_elements">here (see 'find-all' at the end).

[fdb]

Hi joejoe ,



the best way to get the data would be to map over the results and use implicit indexing.



So ref-all would give you a list of indices, probably the data you're looking for is one level up in this structure, then I would do:

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(map (fn(x) (itunes-data (chop x))) (ref-all "Brian Eno" itunes-data))


[cameyo]

Hi joejoe,

the "ref-all" and "ref" functions have a parameter to get data instead of indexes.

Code Select Expand

(setq lst '(a b c (d a f (a h a)) (k a (m n a) (x))))
(ref-all 'a lst)
;-> ((0) (3 1) (3 3 0) (3 3 2) (4 1) (4 2 2))
(ref-all 'a lst = true)
;-> (a a a a a a)
But maybe I misunderstood the question.

cameyo

[newBert]

the "ref-all" and "ref" functions have a parameter to get data instead of indexes.

Well seen ! I had completely forgotten this option.

Thanks, Cameyo.

[joejoe]

Thanks very much for all the exemplars!



ref and map seem to carry things out quite well!



Much appreciated!