scheme - Dereference variable inside list -


is possible dereference variable contained inside list, obtain value? example:

(define 1 1) (define 2 2)  (define list '(one two))  (display (list-ref list 0))

here list-ref references one, , display shows one in letters. instead one dereference value contained homonym variable?

eval can solve problem... situations eval applicable, it's large , dangerous hammer.

matthew flatt's blog post on topic has become go-to explanation:

http://blog.racket-lang.org/2011/10/on-eval-in-dynamic-languages-generally.html

here's how might without eval in racket. stripping away cruft, "dict-ref" can find named element (or elements) in "association list".

#lang racket  (define data   '((one 1)     (two 2)))   (define wanted-list '(two one))  ;; evaluates '((2) (1)): (for/list ([wanted wanted-list])   (dict-ref data wanted))

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