function
boot.janet on line 795 , column 1
(complement f )
Returns a function that is the complement to the argument.
(filter even? [1 2 3 4 5 ]) # => @[2 4]
(filter odd? [1 2 3 4 5 ]) # => @[1 3 5]
(filter (fn [x ] (not (even? x ))) [1 2 3 4 5 ]) # => @[1 3 5]
(filter (complement even? ) [1 2 3 4 5 ]) # => @[1 3 5]
(def fns [even? odd? ])
(map (fn [f ] (filter f [-2 -1 0 1 2 ])) fns ) # => @[ @[-2 0 2] @[-1 1] ]
(def fns (map complement fns ))
(map (fn [f ] (filter f [-2 -1 0 1 2 ])) fns ) # => @[ @[-1 1] @[-2 0 2] ]