Den fredag 10 april 2015 kl. 20:51:09 UTC+2 skrev marc fawzi: > I just noticed that maps where key and value are keywords are used widely, > for example in cljs-ajax and leinnigen configuration > > > Ii'm assuming it's because it's easier to work with values that are keywords > to build other maps from them or do whatever transformations that result in > values becoming keys in the output... and so it's explicit. But maybe I'm > missing the real reason? > > > Is there a good nerdy blog about Clojure that gets into the finer details of > Clojure for those of us who want to turn every atom?
It's common in Clojure to use keywords where in a language like Java you'd use enums. Perhaps a good way to look at the reason to use keywords rather than strings in these situations, is that using strings gives the impression that the actual content of the strings matter (for example for presentation), whereas for keywords, the only important characteristic is that they only equal themselves (and the actual keyword chosen is only important for description, as is typically the case with enums as well). So for example in Leiningen, the fact that the value for :description is a string makes sense since it's used for presenting information about the project, and the properties of the string (for example that it might contain the substring "distributed") may be of interest for other purposes as well. For :update, however, we are simply specifying one of a number of allowed values. We could have used numbers instead, but just like with enums, using keywords make it easier. Besides that rant, I have some vague memory of there being some performance benefit memory-wise to using keywords rather than strings, but I might be mistaken. -- 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.
