*features*-var

[pmf]

Some (most, if not all) CL variants have a *features*-var available
that contains information about what the implementation supports and
what not. Seeing that the issue of determining the Clojure-version in
use come up from time to time, maybe it would be useful to introduce
something like this for Clojure. For example, identifying whether one
is using the lazy (lazier) version would then be possible by checking
for the presence of a flag ":lazy" (in this particular case, checking
for the presence of lazy-seq would be enough, but other feature-sets
might be harder to detect).

[Cosmin Stejerean]

I don't think something like *features* makes sense in Clojure. Unlike CL there isn't an incomplete standard with many slightly different implementations. Requiring a specific version (or range of versions) of Clojure should be sufficient to ensure that the code is run against a compatible version of Clojure. For now I assume that means SVN revision numbers until we get to 1.0

--
Cosmin Stejerean
http://offbytwo.com

[Stuart Sierra]

I've always thought *features* was a nuisance in CL, since very few
values were ever standardized. It ends up being used like browser-
sniffing code in JavaScript.
-Stuart Sierra