http://dev.clojure.org/jira This file is an XML representation of an issue en-us 4.4 649 25-07-2011 http://dev.clojure.org/jira/browse/CLJS-359 ClojureScript <p>`with-meta` does not working on function objects in CLJS. Compilation fails with the following error:</p> <p>Error: No protocol method IWithMeta.-with-meta defined for type function: function <img class="emoticon" src="http://dev.clojure.org/jira/images/icons/emoticons/error.gif" height="16" width="16" align="absmiddle" alt="" border="0"/> { return x; }</p> <p>I tried it out on the REPL and found the following:</p> <p>---------- BEGIN: repl-rhino ----------<br/> ClojureScript:cljs.user&gt; (with-meta #(do :foo) {:foo :bar})<br/> "Error evaluating:" (with-meta (fn* [] (do :foo)) {:foo :bar}) :as "cljs.core.with_meta.call(null,(function (){\nreturn \"\\uFDD0'foo\";\n}),cljs.core.ObjMap.fromObject(<span class="error">&#91;\&quot;\\uFDD0&#39;foo\&quot;&#93;</span>,{\"\\uFDD0'foo\":\"\\uFDD0'bar\"}));\n"<br/> org.mozilla.javascript.JavaScriptException: Error: No protocol method IWithMeta.-with-meta defined for type function: <br/> function () { return "\ufdd0'foo"; }<br/> (cljs/core.cljs#222)<br/> at cljs/core.cljs:222 (anonymous)<br/> at cljs/core.cljs:214 (_with_meta)<br/> at cljs/core.cljs:806 (with_meta)<br/> at &lt;cljs repl&gt;:2 (anonymous)<br/> at &lt;cljs repl&gt;:2</p> <p>nil<br/> ---------- END: repl-rhino ----------</p> <p>Reference: <a href="https://groups.google.com/forum/?fromgroups=#!topic/clojure/pRO-5IlilNM">https://groups.google.com/forum/?fromgroups=#!topic/clojure/pRO-5IlilNM</a></p> CLJS Rhino-REPL and during Compilation CLJS-359

`with-meta` does not work on function objects

Defect Major Resolved Completed David Nolen Shantanu Kumar bug Sat, 25 Aug 2012 16:39:55 -0500 Wed, 21 Nov 2012 16:21:13 -0600 Wed, 21 Nov 2012 16:21:13 -0600 1 4 <p>We could create a fn wrapper type of some kind that implements all the supported arities of IFn (this means the compiler needs to guarantee that args past 20 are collected into an array-seq) that include the extra meta fields. Seems doable.</p> <p>I have created that exact function wrapper - it's in Shoreleave. We can move it into CLJS proper if you like.</p> <p><a href="https://github.com/shoreleave/shoreleave-core/blob/master/src/shoreleave/efunction.cljs">https://github.com/shoreleave/shoreleave-core/blob/master/src/shoreleave/efunction.cljs</a></p> <p>That's nice but would prefer to have as little overhead as possible.</p> <p>ala unrolling the invoke call?</p> <p>More than happy to start pulling together a patch.</p> <p>Yes there's actually an existing ticket for that. Thanks. We also need compiler support for function invocations when there's more then 20 arguments - though that's a different existing ticket.</p> <p>I was just waiting on <a href="http://dev.clojure.org/jira/browse/CLJS-365" title="apply needs to put all args after the 20th into an array seq">CLJS-365</a> to be completed. Did you think of a better approach than the deftype-wrapper? More than happy to push on this.</p> <p>I thought about this some more - this patch is really about adding metadata to functions at runtime - static metadata on defs are stored in cljs.analyzer/namespaces. Given that it's runtime I think your simple patch is actually OK, we can't generally optimize functions like that anyway since we won't have that kind of information available.</p> <p>Patch adds a Function type and extends js/function to support metadata. There is now an Fn marker protocol.</p> <p>Patch also includes an additional commit to fix the behavior of the this variable for IFn definitions.</p> <p>Not tested on JavaScriptCore.</p> <p>v2 of patch improves speed of fn? and utilizes reify to avoid creating an explicit Function type</p> <p>fixed, <a href="http://github.com/clojure/clojurescript/commit/6ce3b1cef3824fd36e75402f5a8ed5053252b15e">http://github.com/clojure/clojurescript/commit/6ce3b1cef3824fd36e75402f5a8ed5053252b15e</a></p> Global Rank Patch Code and Test