code.query.match.optional
pattern-seq
added in 3.0
(pattern-seq pattern)generate a sequence of possible matches (pattern-seq ’(+ ^:? (1) ^:? (^:? + 2))) => ’((+) (+ (1)) (+ (2)) (+ (1) (2)) (+ (+ 2)) (+ (1) (+ 2)))
tag-meta
added in 3.0
(tag-meta ele out)increment a counter everytime a :? element is seen (let out (atom {:? -1}) (tag-meta ^:? () out) @out) => {:? 0}