Data.Generics.Zipper
data Zipper root
toZipper
fromZipper
left
right
down
down'
up
query
trans
transM
getHole
setHole
setHole'
moveQ
leftQ
rightQ
downQ
upQ
moveT
leftT
rightT
downT
upT
moveM
rightM
downM
upM
leftmost
rightmost
zmapQ
zmapT
zmapM
zmapMp
zeverywhere
zeverywhere'
zsomewhere
zreduce