Hi all,
I'm pleased to announce bitwise-0.1:
http://hackage.haskell.org/package/bitwise
--8<-- excerpt from the hackage page
Unboxed multidimensional bit packed Bool arrays with fast aggregate
operations based on lifting Bool operations to bitwise operations.
There are many other bit packed structures out there, but none met all
of these requirements:
1. unboxed bit packed Bool array,
2. multi-dimensional indexing,
3. fast (de)serialization, or interoperable with foreign code,
4. fast aggregate operations (fold, map, zip).
--8<-- end excerpt
bitwise has been tested in hugs -98, ghc-7.0.4, ghc-7.4.1.
Bool data structures comparison (features numbered as excerpt above):
package features additional notes
1 2 3 4
array Y Y n n
bitarray Y n n ? based on array
bitstream n n ? ? based on vector
bitstring Y n ? ? based on bytestring
bit-vector n n Y ? based on vector
bitwise Y Y Y Y
repa n Y Y ? based on vector
uvector Y n ? ? deprecated
vector n n Y ? uses a Word8 for each Bool
Known shortcomings of this first release of bitwise:
* missing common instances (Eq, Ord, Read, Show, ...);
* missing additional functions (counting, searching, ...);
* missing documentation on ByteString format: the bits are taken
from the array and packed into Word8s, with the first bit (in array
order) becoming the least significant bit of the first Word8; the
last Word8 is padded with 0 at the most-significant-bit end;
* PBM reading is not compliant to the official specification;
* misleading benchmark (bitwise zipWith is fast, but there may be a
faster way to zipWith UArray ix Bool than the one I used).
What I'm using bitwise for at the moment:
A building block for fractal imaging: an image is made up of cells,
each cell can be in one of 4 states (represented with 2 bits):
* cell is 100% interior to a set of points in the plane
* cell is 100% exterior
* partially interior and partially exterior (ie, on the boundary)
* unknown
with recursive subdivision of cells into images taking place only
when the cell is on the boundary of the set being imaged.
Thanks,
Claude
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