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How define variables in a macro, so that they available for the caller of the macro

开发者 https://www.devze.com 2023-01-31 02:08 出处:网络
I want to have a macro dbtest that can be used like this: (dbtest (prn test-object1) (prn test-object2))

I want to have a macro dbtest that can be used like this:

(dbtest
  (prn test-object1)
  (prn test-object2))

test-object1 and test-object2 should be variables which are defined by dbtest (because I need them everytime I use the dbtest macro). "prn" is just an example; I want to use arbitrary code inside the macro.

I tried this:

(defmacro dbtest [& body]
  `(sql/with-connection db
     (delete-all-tables)
     (let [~'test-object1 (insert-object "foo")]
       ~@body)))

where insert-object is a function that insert something into the DB and returns a the corresponding data structure.

But it 开发者_JAVA百科doesn't work: I get a "no such var" error


It works for me:

user=> (defmacro let-test [& body]
         `(let [~'test-object1 123] ~@body))
#'user/let-test
user=> (let-test (+ test-object1 321))
444

Are you sure the problem isn't with the SQL-related calls?

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