number special and chunked encoding

gistfile1.txt

(let [chunked
      # https://en.wikipedia.org/wiki/Chunked_transfer_encoding#Encoded_data
      (string "4\r\n"
              "Wiki\r\n"
              "6\r\n"
              "pedia \r\n"
              "E\r\n"
              "in \r\n"
              "\r\n"
              "chunks.\r\n"
              "0\r\n"
              "\r\n")]
  (peg/match ~(some (sequence
                      (number :h+ 16 :length)
                      "\r\n"
                      (capture
                        (lenprefix (backref :length)
                                   1))
                      "\r\n"))
             chunked))
# => @[4 "Wiki" 6 "pedia " 14 "in \r\n\r\nchunks." 0 ""]