CODEWITHSUNDEEP
clojuremacroseval
Kevin Kostlan
Kevin Kostlan

Reputation: 3519

clojure quoting inside let

Quoting (both syntax and non-syntax) seems to fail to detect vars inside a let statement:

(let [foo 1] (eval `(print foo)))

This will generate an error or use whatever prior value bound was bound to foo in (def foo bar). Is there a way to make the syntax quote use the "local" variables that let defined instead?

Upvotes: 0

Views: 246

Answers (2)

Frank C.
Frank C.

Reputation: 8096

Kevin

You were close, this should do the work (basically, you should unquote the local var in the quoted statement)

(let [foo 1] (eval `(print ~foo)))

Also, while eval is certainly a valid language function, what is the overall goal? There may be better ways altogether.

Frank

Upvotes: 1

Charles Duffy
Charles Duffy

Reputation: 295805

Unquote to substitute the value:

(let [foo 1] (eval `(print ~foo)))

...or explicitly bind your variables:

(declare :^dynamic foo)
(binding [foo 1] (eval '(print foo)))

See Variable scope + eval in Clojure for details.

Upvotes: 2

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