Print Page - Retrieving the value of a symbol

Title: Retrieving the value of a symbol
Post by: cameyo on February 11, 2019, 10:33:07 AM

These expressions generate an error:

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(set '"name") -> ERR: symbol expected in function set : '"name"
(set (quote "name") 3) -> ERR: symbol expected in function set : '"name"

But the following are valid (then "name" is a valid symbol):

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(setf '"name" 3) -> 3
(setq "name" 3) -> 3

Now the problem: how to retrieve the value of the symbol "name"?

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(println "name") -> name

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(setq a "name")
(println a) -> "name"

Thanks

Title: Re: Retrieving the value of a symbol
Post by: fdb on February 11, 2019, 12:20:33 PM

Hi, I presume you want to convert a string into a symbol , which can be done like this:

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(set (sym "name") 3)

name ->3

If you however want to convert "name" including quotes into a symbol then use this code:

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(set (sym {"name"}) 3)

and to retrieve the value from "name":

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(eval (sym {"name"})) -> 3

Title: Re: Retrieving the value of a symbol
Post by: cameyo on February 11, 2019, 12:53:08 PM

You solve my question with:

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(eval (sym {"name"})) -> 3

Thanks fdb :-)

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Forum => Whither newLISP? => Topic started by: cameyo on February 11, 2019, 10:33:07 AM