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support $ op for bit arrays/seqs

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Zahary Karadjov 2019-07-25 18:54:23 +03:00
parent 30e084f76f
commit ff326d686c
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GPG Key ID: C8936F8A3073D609
1 changed files with 19 additions and 9 deletions
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28
stew/bitseqs.nim
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@ -8,7 +8,7 @@ type
BitArray*[bits: static int] = object
bytes*: array[(bits + 7) div 8, byte]
proc len*(s: BitSeq): int =
func len*(s: BitSeq): int =
let
bytesCount = s.Bytes.len
lastByte = s.Bytes[bytesCount - 1]
@ -16,10 +16,13 @@ proc len*(s: BitSeq): int =
Bytes(s).len * 8 - (8 - markerPos)
template len*(a: BitArray): int =
a.bits
template bytes*(s: BitSeq): untyped =
Bytes(s)
proc add*(s: var BitSeq, value: bool) =
func add*(s: var BitSeq, value: bool) =
let
lastBytePos = s.Bytes.len - 1
lastByte = s.Bytes[lastBytePos]
@ -34,27 +37,27 @@ proc add*(s: var BitSeq, value: bool) =
s.Bytes[lastBytePos].setBit 7, value
s.Bytes.add byte(1)
proc `[]`*(s: BitSeq, pos: Natural): bool {.inline.} =
func `[]`*(s: BitSeq, pos: Natural): bool {.inline.} =
doAssert pos < s.len
s.Bytes.getBit pos
proc `[]=`*(s: var BitSeq, pos: Natural, value: bool) {.inline.} =
func `[]=`*(s: var BitSeq, pos: Natural, value: bool) {.inline.} =
doAssert pos < s.len
s.Bytes.setBit pos, value
proc raiseBit*(s: var BitSeq, pos: Natural) {.inline.} =
func raiseBit*(s: var BitSeq, pos: Natural) {.inline.} =
doAssert pos < s.len
raiseBit s.Bytes, pos
proc lowerBit*(s: var BitSeq, pos: Natural) {.inline.} =
func lowerBit*(s: var BitSeq, pos: Natural) {.inline.} =
doAssert pos < s.len
lowerBit s.Bytes, pos
proc init*(T: type BitSeq, len: int): T =
func init*(T: type BitSeq, len: int): T =
result = BitSeq newSeq[byte](1 + len div 8)
Bytes(result).raiseBit len
proc init*(T: type BitArray): T =
func init*(T: type BitArray): T =
# The default zero-initializatio is fine
discard
@ -74,7 +77,7 @@ template lowerBit*(a: var BitArray, pos: Natural) =
# At the moment, it doesn't work quite well because Nim selects
# the generic cmp[T] from the system module instead of choosing
# the openarray overload
proc compareArrays[T](a, b: openarray[T]): int =
func compareArrays[T](a, b: openarray[T]): int =
result = cmp(a.len, b.len)
if result != 0: return
@ -88,3 +91,10 @@ template cmp*(a, b: BitSeq): int =
template `==`*(a, b: BitSeq): bool =
cmp(a, b) == 0
func `$`*(a: BitSeq): string =
let length = a.len
result = newStringOfCap(2 + length)
result.add "0b"
for i in 0 ..< length:
result.add if a[i]: '1' else: '0'