Package bitarray provides a convenient and fast BitArray data structure that compactly stores bits in Go.
Just do go get github.com/c2akula/bitarray to install the package.
The package provides a single type BitArray. It exposes an api to work with booleans but internally stores them as bits in uint64s.
ba := bitarray.New(65) // creates a bitarray containing 65 bitsba.Set(5) // sets the bit at position 5 b := ba.Chk(5) // gets the bit at position 5 ba.Tgl(5) // toggles the bit at position 5 ba.Clr(5) // clears the bit at position 5 ba.Cnt() // returns the number of set bitsoldValue := ba.ChkSet(5) // returns the value at position 5 before setting it oldValue := ba.ChkClr(5) // returns the value at position 5 before clearing it v := bit.One ba.Swap(5, &v) // swaps the value at position 5 with v ba.SetAll() // sets all the bits ba.ClrAll() // clears all the bitsThere are two procedures CopyRange and SwapRange to help work with a range of bits. ARange represents a span over a certain number of bits starting at a specific position.
b1 := FromStr("11001001") b2 := FromStr("00101110") // copy 3 bits starting at position 3 from `b2` into `b1` starting at position 1 bitarray.CopyRange(b1.Range(1, 3), b2.Range(3, 3)) fmt.Println("b1: ", &b1) // b1 = "10111001"CopyRange copies number of bits equal to that of the smaller range.
b1 := FromStr("11001001") b2 := FromStr("00101110") // swap 3 bits starting at position 3 from `b2` with `b1` starting at position 1 bitarray.SwapRange(b1.Range(1, 3), b2.Range(3, 3)) fmt.Println("b1: ", b1, "b2: ", b2) // b1 = "10111001" b2 = "00110010" SwapRange swaps number of bits equal to that of the smaller range.
Tests and benchmarks can be found in ba_test.go.
goos: windows goarch: amd64 pkg: github.com/c2akula/bitarray BenchmarkNew-8 40094756 28.1 ns/op 32 B/op 1 allocs/op BenchmarkBitArray/chk-8 3957813 297 ns/op 0 B/op 0 allocs/op BenchmarkBitArray/put-8 853075514 1.41 ns/op 0 B/op 0 allocs/op BenchmarkBitArray/set-8 846415746 1.43 ns/op 0 B/op 0 allocs/op BenchmarkBitArray/tgl-8 847111244 1.45 ns/op 0 B/op 0 allocs/op BenchmarkBitArray/swap-range,_best-case-8 80213366 14.9 ns/op 0 B/op 0 allocs/op BenchmarkBitArray/swap-range,_worst-case-8 6011475 184 ns/op 0 B/op 0 allocs/op BenchmarkBitArray/copy-8 251309268 4.76 ns/op 0 B/op 0 allocs/op BenchmarkBitArray_Cnt/cnt_-_bits-8 191233108 6.28 ns/op 0 B/op 0 allocs/op BenchmarkCopyRange/worst_case_-_unaligned_copy-8 705885 1703 ns/op 0 B/op 0 allocs/op BenchmarkCopyRange/best_case_-_aligned_copy-8 122504306 9.54 ns/op 0 B/op 0 allocs/op If you come across any bugs, please use the issue tracker. I will try to get back to you as soon as possible.