any particular reason why IPersistentSet has its own get(Object) and doesn't implement ILookup?

IPersistentSet almost certainly pre-dates ILookup (which was added later)

is IPersistentSet.get() really the same intent as ILookup.valAt()?

I'd say so

this comes from a discussion over #clojure-uk where i was explaining why it doesnt make sense for sets to be IAssociative, but I was quite surprised to find out that they weren't ILookup

if there's no good semantical reason (and I can't think of one!) for IPS to be an ILookup i'd be tempted to make an enhancement ticket

adding ILookup to IPersistentSet would be a breaking change for existing (non-core) impls of IPS

could be added to Set impls though

that would theoretically make calls to sets of keywords faster?

I believe so

hmm, wait, depends on what you're talking about :)

if you meant because of KeywordLookup, no

no, I meant on get

that's only there as an inline cache for record access IIRC

yeah

would avoid being routed through getFrom

not specific to sets of keywords tho

right