A bit vector is an array data structure that compactly stores bits.
This library is based on 5 static different data structures:
- 8-bit vector: relies on an internal
uint8 - 16-bit vector: relies on an internal
uint16 - 32-bit vector: relies on an internal
uint32 - 64-bit vector: relies on an internal
uint64 - 128-bit vector: relies on two internal
uint64(for ASCII problems)
The rationale of using a static integer compared to a dynamic []byte is first of all to save memory.
There is no structure and/or slice overhead.
Hence, you might be interested in this library for memory-bound computation.
Also, the operations (get, set, etc.) are way more efficient. A simple benchmark shows that it's about 10 times more efficient than using a byte slice. Moreover, there is a guarantee that the internal bit vectors will not escape to the heap and remain only at the stack level.
Yet, the only drawback is to have a fixed-size bit vector (8, 16, 32, 64 or 128). If you require a dynamic bit vector, you should take a look at dropbox/godropbox for example.
go get github.com/teivah/bitvector
- 8-bit vector:
var bv bitvector.Len8- 16-bit vector:
var bv bitvector.Len16- 32-bit vector:
var bv bitvector.Len32- 64-bit vector:
var bv bitvector.Len64- 128-bit vector:
var bv bitvector.Ascii
// Or to reinitialize the bit vector
bv = bitvector.NewAscii()- Set ith bit:
bv = bv.Set(i, true)
bv = bv.Set(i, false)- Get ith bit:
b := bv.Get(i) // bool- Toggle (flip) ith bit:
bv = bv.Toggle(i)- Clear bits from index i (included) to index j (excluded):
bv = bv.Clear(i, j)- Count the number of bits set to 1:
i := bv.Count() // uint8- And operator:
bv := bv1.And(bv2)- Or operator:
bv := bv1.Or(bv2)- Xor operator:
bv := bv1.Xor(bv2)- AndNot operator:
bv := bv1.AndNot(bv2)- Push operator (left shift):
bv = bv.Push(2)- Pop operator (right shift):
bv = bv.Pop(2)- Convert the internal bit vector structure to a string:
s := bv.String() // string