| Portability | portable |
|---|---|
| Stability | provisional |
| Maintainer | John Lato <jwlato@gmail.com> |
| Safe Haskell | Safe-Inferred |
Data.ListLike.FoldableLL
Contents
Description
Generic tools for data structures that can be folded.
Written by John Goerzen, jgoerzen@complete.org
- class FoldableLL full item | full -> item where
- fold :: (FoldableLL full item, Monoid item) => full -> item
- foldMap :: (FoldableLL full item, Monoid m) => (item -> m) -> full -> m
- foldM :: (Monad m, FoldableLL full item) => (a -> item -> m a) -> a -> full -> m a
- sequence_ :: (Monad m, FoldableLL full (m item)) => full -> m ()
- mapM_ :: (Monad m, FoldableLL full item) => (item -> m b) -> full -> m ()
FoldableLL Class
class FoldableLL full item | full -> item whereSource
This is the primary class for structures that are to be considered
foldable. A minimum complete definition provides foldl and foldr.
Instances of FoldableLL can be folded, and can be many and varied.
These functions are used heavily in Data.ListLike.
Methods
foldl :: (a -> item -> a) -> a -> full -> aSource
Left-associative fold
foldl' :: (a -> item -> a) -> a -> full -> aSource
Strict version of foldl.
foldl1 :: (item -> item -> item) -> full -> itemSource
A variant of foldl with no base case. Requires at least 1
list element.
foldr :: (item -> b -> b) -> b -> full -> bSource
Right-associative fold
foldr' :: (item -> b -> b) -> b -> full -> bSource
Strict version of foldr
foldr1 :: (item -> item -> item) -> full -> itemSource
Like foldr, but with no starting value
Instances
| FoldableLL ByteString Word8 | |
| FoldableLL ByteString Word8 | |
| FoldableLL CharStringLazy Char | |
| FoldableLL CharString Char | |
| FoldableLL [a] a | |
| FoldableLL (Seq a) a | |
| Ix i => FoldableLL (Array i e) e |
Utilities
fold :: (FoldableLL full item, Monoid item) => full -> itemSource
foldMap :: (FoldableLL full item, Monoid m) => (item -> m) -> full -> mSource
Map each element to a monoid, then combine the results
foldM :: (Monad m, FoldableLL full item) => (a -> item -> m a) -> a -> full -> m aSource
Monadic version of left fold, similar to foldM.
sequence_ :: (Monad m, FoldableLL full (m item)) => full -> m ()Source
mapM_ :: (Monad m, FoldableLL full item) => (item -> m b) -> full -> m ()Source
A map in monad space, discarding results.