TBits

[Properties (by Name)][Methods (by Name)][Events (by Name)]

Class to store collections of bits (binary values that can be 0 or 1)

Declaration

Source position: classesh.inc line 384

Type
  TBits = class (TObject)
  private
    FBits : ^TBitArray;
    FSize : LongInt;
    FBSize : LongInt;
    findIndex : LongInt;
    findState : Boolean;
    procedure SetBit(bit: LongInt; value: Boolean);
    procedure SetSize(value: LongInt);
  protected
    procedure CheckBitIndex(Bit: LongInt; CurrentSize: Boolean);
  public
    constructor Create(TheSize: LongInt);  Virtual;
    destructor Destroy;  Override;
    function GetFSize : LongInt;
    procedure SetOn(Bit: LongInt);
    procedure Clear(Bit: LongInt);
    procedure Clearall;
    procedure CopyBits(BitSet: TBits);
    procedure AndBits(BitSet: TBits);
    procedure OrBits(BitSet: TBits);
    procedure XorBits(BitSet: TBits);
    procedure NotBits(BitSet: TBits);
    function Get(Bit: LongInt) : Boolean;
    procedure Grow(NBit: LongInt);
    function Equals(Obj: TObject) : Boolean;  Override;  Overload;
    function Equals(BitSet: TBits) : Boolean;  Overload;
    procedure SetIndex(Index: LongInt);
    function FindFirstBit(State: Boolean) : LongInt;
    function FindNextBit : LongInt;
    function FindPrevBit : LongInt;
    function OpenBit : LongInt;
    Bits[Bit: LongInt]: Boolean; default;
    Size : LongInt;
  end
  ;

Description

TBits can be used to store collections of bits in an indexed array. This is especially useful for storing collections of booleans: Normally the size of a boolean is the size of the smallest enumerated type, i.e. 1 byte. Since a bit can take 2 values it can be used to store a boolean as well. Since TBits can store 8 bits in a byte, it takes 8 times less space to store an array of booleans in a TBits class then it would take to store them in a conventional array.

TBits introduces methods to store and retrieve bit values, apply masks, and search for bits.

Members

Member	Type	Visibility	Description
AndBits	Method	public	Performs an and operation on the bits.
Bits	Property	public	Access to all bits in the array.
CheckBitIndex	Method	protected
Clear	Method	public	Clears a particular bit.
Clearall	Method	public	Clears all bits in the array.
CopyBits	Method	public	Copy bits from one bits set to another
Create	Method	public	Creates a new bits collection.
Destroy	Method	public	Destroys a bit collection
Equals	Method	public	Determines whether the bits of 2 arrays are equal.
FBits	Field	private
FBSize	Field	private
FindFirstBit	Method	public	Find first bit with a particular value
findIndex	Field	private
FindNextBit	Method	public	Searches the next bit with a particular value.
FindPrevBit	Method	public	Searches the previous bit with a particular value.
findState	Field	private
FSize	Field	private
Get	Method	public	Retrieve the value of a particular bit
GetFSize	Method	public	Returns the number of records used to store the bits.
Grow	Method	public	Expands the bits array to the requested size.
NotBits	Method	public	Performs a not operation on the bits.
OpenBit	Method	public	Returns the position of the first bit that is set to False.
OrBits	Method	public	Performs an or operation on the bits.
SetBit	Method	private
SetIndex	Method	public	Sets the start position for FindNextBit and FindPrevBit
SetOn	Method	public	Turn a particular bit on.
SetSize	Method	private
Size	Property	public	Current size of the array of bits.
XorBits	Method	public	Performs a xor operation on the bits.

Inheritance

Class	Description
TBits	Class to store collections of bits (binary values that can be 0 or 1)

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