function
/usr/local/lib/janet/spork/generators.janet on line 141 , column 1
(mapcat f iterable & iterables )
Returns a coroutine that yields elements of (f
first-element-of-iterable ;first-elements-of-iterables ), elements
of (f second-element-of-iterable ;second-elements-of-iterables ),
elements of (f third-element-of-iterable
;third-elements-of-iterables ), and so on until any of the given
iterables doesn 't have any more element.