Cricket over ledger

Write up the bowler's figures, over by over, from a ball-by-ball log of a cricket match.

An over is made of six legal deliveries. Wides and no-balls are not legal: they are extra deliveries that the bowler must bowl again. Each delivery is a string:

• "0" to "6": a legal delivery; that many runs came off the bat.
• "W": a legal delivery that took a wicket and scored no runs.
• "b1" to "b4": a legal delivery on which the batters ran that many byes.
• "wd" or "wd<n>": a wide, which costs 1 + n runs (n = 0 when no number follows).
• "nb" or "nb<n>": a no-ball, which costs 1 + n runs (n runs came off the bat).

Runs charged to the bowler are the bat runs, plus everything a wide or a no-ball costs. Byes are not charged to the bowler.

An over ends right after its sixth legal delivery; the next delivery in the log, whatever it is, starts the next over. The log may end in the middle of an over. A wicket on a legal delivery counts as one wicket for the over. An over is a maiden when it has all six legal deliveries and the bowler was charged zero runs in it.

Input: deliveries, a list of strings in the order they were bowled.

Output: a list with one entry [legal, charged, wickets, maiden] for each over that has at least one delivery, in order. maiden is 1 or 0. Return [] for an empty log.