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POmacro-producing macro invoked from another namespace :: Can't refer to qualified var that doesn't exist
 

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  1. POmacro-producing macro invoked from another namespace :: Can't refer to qualified var that doesn't exist
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    <p>I have a macro-producing macro which I am trying to call from another namespace and it fails with "Can't refer to qualified var that doesn't exist".</p> <p>I managed to reproduce it in the following code which is the simplest possible that exemplifies the problem. I also found a workaround, however I would like to understand the cause of the problem and whether some better solution exists.</p> <h1>problem</h1> <h3> file foo.clj </h3> <pre><code>(ns foo) (defmacro create-my-macro [] `(defmacro my-macro [] nil)) </code></pre> <h3> file boo.clj </h3> <pre><code>(ns boo (:use [foo])) (create-my-macro) </code></pre> <p>The above code when executed with:</p> <pre><code>java -cp clojure-1.4.0.jar clojure.main boo.clj </code></pre> <p>... fails with:</p> <pre><code>Exception in thread "main" java.lang.RuntimeException: Can't refer to qualified var that doesn't exist, compiling:(...boo.clj:2) </code></pre> <h1>workaround</h1> <p>For some reason, when the macro-producing macro is enhanced to accept a name for the macro to be created as a parameter, there is no failure.</p> <h3>file foo.clj</h3> <pre><code>(ns foo) (defmacro create-my-macro [macroName] (let [the-macroName (symbol macroName)] `(defmacro ~the-macroName [] 1))) </code></pre> <h3>file boo.clj</h3> <pre><code>(ns boo (:use [foo])) (create-my-macro "foo") (println (foo)) </code></pre> <p>Running file boo.clj as above outputs a clean "1" on the console without any complains.</p> <p>So, what was wrong in the first case and is there another way to fix it changing the macro-producing-macro to accept a name for the macro to be produced as a parameter? Also, why doesn't it fail when the macro-generating-macro is called from the same namespace?</p>
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