merge

(merge m ...)

Answers one fresh table over every argument's pairs, later maps winning; no argument is mutated. (merge) is nil, and a merge of all-nil arguments is nil too. The result keeps a record's type only when the first argument is one, like the oracle: a nil first argument answers a plain map even when a later map is a record. Merge is conj folded over the maps, so a later argument may also be a sorted map, a [k v] vector, a seq of entries or a Java Map (interpreter and JVM); nil adds nothing and a list of non-entries signals.

As a value a rest lambda over the maps.