janet peg peg/match struct example

struct.janet

(first
  (peg/match ~(cmt (sequence (capture "hello")
                             (some (set " ,"))
                             (capture "world"))
                   ,(fn [cap1 cap2]
                      {:greeting cap1 :name cap2}))
             "hello, world"))
# => {:greeting "hello" :name "world"}