diff options
Diffstat (limited to 'StackSet.hs')
| -rw-r--r-- | StackSet.hs | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/StackSet.hs b/StackSet.hs index 15788bc..1453c97 100644 --- a/StackSet.hs +++ b/StackSet.hs @@ -61,6 +61,10 @@ empty n = StackSet { current = 0 member :: Ord a => a -> StackSet a -> Bool member a w = M.member a (cache w) +-- | /O(log n)/. Looks up the stack that x is in, if it is in the StackSet +lookup :: (Monad m, Ord a) => a -> StackSet a -> m Int +lookup x w = M.lookup x (cache w) + -- | /O(n)/. Number of stacks size :: StackSet a -> Int size = M.size . stacks |