BitModule

[said]

Thanks idle for sharing ... very nice and useful

[idle]

fixed a bug in the bittrie reallocation

[said]

Hi Idle

looks like something is wrong with BitArray (probably other structures as well haven't tested), try the below you will see that position 14 (or 15 if we start at 1) is being set not 9!

Code: Select all

Define ar.BitModule::IBitArray
ar = BitModule::New_BitArray(20)
ar\Set(9)
Define *q.ascii, *p = ar\GetBuffer()
Define i,txt.s
For i=0 To MemorySize(*p)
    *q = *p + i
    txt + RSet( Bin(*q\a), 8, "0") + ">"
Next
Debug txt

output

Code: Select all

00000000>00000010>00000000> ....

[Demivec]

looks like something is wrong with BitArray (probably other structures as well haven't tested), try the below you will see that position 14 (or 15 if we start at 1) is being set not 9!

You're examining the buffer directly and not in the manner that the BitArray does.

If you use the BitArray's interface instead:

Code: Select all

Define ar.BitModule::IBitArray
ar = BitModule::New_BitArray(20)
ar\Set(9)
Define i,txt.s
For i=0 To ar\BitSize()
    txt + Str(Bool(ar\get(i) = 1))
    If i % 8 = 0 And i > 0
      txt + ">"
    EndIf
Next
Debug txt

The output produced looks like:

Code: Select all

000000000>10000000>00000000> ....

Everything looks as it should.

[said]

Thanks Demivec for clarifying, now i looked in detail on what's going on and i see that each byte is being processed separately. You are right, yes it is working fine but honestly I was not expecting this ... (should never use blindly anything )
I was planning to use this to store blocks in files that could be read by other applications, this somehow put restrictions on the usage of this great module

[idle]

Hi Said, it's easy enough fix I think

if you change the set and get parts after the "<<" to (7-(index & $07)

Code: Select all

  *ta\a | (1 << (7-(index & $07))) 

I've updated the module with the changes, seems to be ok

[said]

Thanks Idle for updating the module (actually i had already changed it here to suit my needs, exactly as you are suggesting). It is your module and you know all the details, modifications coming from you are the most welcome ones

Thanks again for sharing this very useful work

[Justin]

What is Toggle suposed to do? I thought would invert the bit value, but does nothing.

Code: Select all

EnableExplicit
Define ba.BitModule::IBitArray
ba = BitModule::New_BitArray(4)
ba\Set(2)
Debug ba\Get(2)
ba\Toggle(2)
Debug ba\Get(2)

[idle]

it's a bug left over from reversing the order, replace it with

Code: Select all

Procedure BitArray_Toggle(*this.bitbuffer,index)
   Protected *ta.Ascii 
    If ((index) >> 3) >= *this\inf\size
      *this\inf\size = index + 64
      *this\inf\BytesUsed = *this\inf\size
      *this\buf = ReAllocateMemory(*this\buf,*this\inf\size)
   EndIf
   If *this\buf
      *ta = *this\buf + ((index)>>3)
      *ta\a ! (1 << (7-(index & $07)))
   EndIf
EndProcedure   

[idle]

v 1.3.8
Updated to pb 5.42 lts
exported hash functions
removed crc32
added asm popcount x86/x64 and SSE 4.2 for bitcount
added shift left / right (nicked from wilbert)

[davido]

@idle,
Very useful, thank you.