Not dirty, it's the very reason extend-type exists. That said you absolutely should not be doing something like this to FileList or HTMLCollection in library code - only application code.
David On Thu, Oct 2, 2014 at 2:15 PM, Marcus Lewis <[email protected]> wrote: > Ok. Extend-type feels a little dirty, since it's relatively invisible (you > can't tell by looking at code that it's dealing with FileLists or > HTMLCollections, so you could be deceived into thinking this code will "just > work" in other contexts, not knowing that it's depending on an extend-type > somewhere else in the codebase). But I think I get where you're coming from. > > On Thursday, October 2, 2014 9:00:15 AM UTC-7, David Nolen wrote: >> You can solve this yourself with extend-type. We're not going to do any >> detection around array likes in core. >> >> On Thursday, October 2, 2014, Marcus Lewis <[email protected]> wrote: >> => (doseq [file lastFileList] (.-name file)) >> >> Error: [object FileList] is not ISeqable >> >> at Error (native) >> >> at cljs.core.seq (http://localhost:8080/app.js:3164:67) >> >> >> >> => (doseq [file (array-seq lastFileList)] (.log js/console (.-name file))) >> >> >> >> This works. It logs the filename. In case you're curious, this FileList is >> coming from drag-drop events) >> >> >> >> Here's the ClojureScript that I would hope would catch this: >> >> (array? coll) >> >> (when-not (zero? (alength coll)) >> >> (IndexedSeq. coll 0)) >> >> >> >> The resulting js is: >> >> if (a instanceof Array || "string" === typeof a) { >> >> return 0 === a.length ? null : new cljs.core.IndexedSeq(a, 0); >> >> } >> >> >> >> Is there any reason not to make other array-like types ISeqable? I'm sure >> there are better examples than FileList. For example, the same issue can be >> seen with HTMLCollection: >> >> >> >> => (seq (.getElementsByTagName js/document.body "div")) >> >> Error: [object HTMLCollection] is not ISeqable >> >> at Error (native) >> >> at cljs.core.seq (http://localhost:8080/app.js:3164:67) >> >> >> >> -- >> >> Note that posts from new members are moderated - please be patient with your >> first post. >> >> --- >> >> You received this message because you are subscribed to the Google Groups >> "ClojureScript" group. >> >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> >> To post to this group, send email to [email protected]. >> >> Visit this group at http://groups.google.com/group/clojurescript. > > -- > Note that posts from new members are moderated - please be patient with your > first post. > --- > You received this message because you are subscribed to the Google Groups > "ClojureScript" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/clojurescript. -- Note that posts from new members are moderated - please be patient with your first post. --- You received this message because you are subscribed to the Google Groups "ClojureScript" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/clojurescript.
