returns a generator iteratively using yield

(gen (loop i 10 (if-not (zero? i) (do (yield i) (recur (dec i)))))) => ’(10 9 8 7 6 5 4 3 2 1)

(->> (gen (loop i 0 (if (even? i) (yield i)) (recur (inc i)))) (take 5)) => 0 2 4 6 8

macroexpand code, keeping the original meta

appends :form/yield to the form meta

testing inputs for visit

returns the visitor dispatch

(visit-sym ’(if :a 1 2)) => ’if

(visit-sym ’(yield 1)) => ’yield

(visit-sym ’(std.lib.generate/yield 1)) => ’yield

checks if form has been visted

(-> (tag-visited ’(loop (+ 1 2 3))) visited?) => true

yields single value has to be used to within gen form

(yield 1) => (throws)

same as yield but returns entire seq