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POClojure macro Instantiation Exception
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copied!<p>I have a macro which works in the repl, and it seems to work in my code outside the <code>let</code> and also inside the <code>let</code> as follows. However it also breaks and I have no idea why. The macro basically just takes the first arg as a function to call, and puts <code>into-array</code> before the last set of arguments, and it adds the class of the final non-collection argument as a parameter to into-array, if it is in the java class heirarchy.</p> <pre><code>(defmacro jvar [method & args] (let [lastargs (last args) evaled-lastargs (eval lastargs)] (if (coll? evaled-lastargs) (let [firstargs (butlast args) klass (eval (last firstargs)) supset (map #(supers (class %)) evaled-lastargs) common (apply intersection #{klass} supset)] (if (seq common) `(~method ~@(butlast firstargs) (into-array ~(first common) ~lastargs)) `(~method ~@firstargs (into-array ~lastargs)))) (throw (Error. "Last argument must be defn."))))) </code></pre> <p>Usages: In Repl: </p> <pre><code>jfxcircles.core> (macroexpand '(jvar Group. Node [(Circle. 100)])) (new Group (clojure.core/into-array javafx.scene.Node [(Circle. 100)])) jfxcircles.core> (jvar Group. Node [(Circle. 100)]) #<Group Group@c26729e> </code></pre> <p>In <code>let</code>: </p> <pre><code>(let [root (Group.) scene (Scene. root 800 600) ;etc. this is for JavaFX ... circ (Circle. 100) inner-group1 (jvar Group. [(Circle. 100)]) ; works inner-group2 (jvar Group. [circ]) ; Instantiation Exception inner-group3 (jvar Group. [(Rectangle. 100 100)]) ; works inner-group4 (jvar Group. [(Rectangle. (.getWidth scene) 100)]) ; Instantiation exception ) </code></pre> <p>So basically it won't compile under certain circumstances that should otherwise be the same, and I'm unable to do macroexpand because it won't compile. Any ideas?</p> <p>thanks</p>

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