reflex::Bits Class Reference

updated Tue Sep 26 2017 by Robert van Engelen
 
Classes | Public Member Functions | Static Public Attributes | Private Member Functions | Private Attributes | List of all members
reflex::Bits Class Reference

RE/flex Bits class for dynamic bit vectors. More...

#include <bits.h>

Classes

struct  Bitref
 References a single bit, returned by operator[]. More...
 

Public Member Functions

 Bits ()
 Construct an empty bit vector. More...
 
 Bits (const Bits &bits)
 Copy constructor. More...
 
 Bits (size_t n)
 Construct a bit vector and set n'th bit. More...
 
 Bits (size_t n1, size_t n2)
 Construct a bit vector and set a range of bits n1'th to n2'th. More...
 
 ~Bits ()
 Destroy bits. More...
 
Bitsoperator= (const Bits &bits)
 Assign bits. More...
 
Bitref operator[] (size_t n)
 Reference n'th bit in the bit vector to assign a value to that bit. More...
 
bool operator[] (size_t n) const
 Returns n'th bit. More...
 
Bitsinsert (size_t n)
 Insert and set a bit in the bit vector. More...
 
Bitserase (size_t n)
 Erase a bit in the bit vector. More...
 
Bitsflip (size_t n)
 Flips a bit in the bit vector. More...
 
Bitsinsert (size_t n1, size_t n2)
 Insert and set a range of bits in the bit vector. More...
 
Bitserase (size_t n1, size_t n2)
 Erase a range of bits in the bit vector. More...
 
Bitsflip (size_t n1, size_t n2)
 
Bitsoperator|= (const Bits &bits)
 Bit-or (set union) the bit vector with the given bits. More...
 
Bitsoperator&= (const Bits &bits)
 Bit-and (set intersection) the bit vector with the given bits. More...
 
Bitsoperator^= (const Bits &bits)
 Bit-xor the bit vector with the given bits. More...
 
Bitsoperator-= (const Bits &bits)
 Bit-delete (set minus) the bit vector with the given bits. More...
 
Bits operator| (const Bits &bits) const
 Bit-or (set union) of two bit vectors. More...
 
Bits operator& (const Bits &bits) const
 Bit-and (set intersection) of two bit vectors. More...
 
Bits operator^ (const Bits &bits) const
 Bit-xor of two bit vectors. More...
 
Bits operator- (const Bits &bits) const
 Bit-delete (set minus) of two bit vectors. More...
 
Bits operator~ () const
 Complement of the bit vector with all bits flipped. More...
 
bool operator== (const Bits &bits) const
 Returns true if bit vectors are equal. More...
 
bool operator!= (const Bits &bits) const
 Returns true if bit vectors are unequal. More...
 
bool operator< (const Bits &bits) const
 Returns true if the bit vector is lexicographically less than the given right-hand side bits. More...
 
bool operator> (const Bits &bits) const
 Returns true if the bit vector is lexicographically greater than the given right-hand side bits. More...
 
bool operator<= (const Bits &bits) const
 Returns true if the bit vector is lexicographically less-or-equal to the given right-hand side bits. More...
 
bool operator>= (const Bits &bits) const
 Returns true if the bit vector is lexicographically greater-or-equal to the given right-hand side bits. More...
 
bool all () const
 Returns true if all bits are set. More...
 
bool any () const
 Returns true if any bit is set. More...
 
Bitsclear ()
 Erase all bits. More...
 
Bitsflip ()
 Flip all bits. More...
 
Bitsreserve (size_t len)
 Reserves space in the bit vector for len bits without changing its current content. More...
 
size_t size () const
 Returns the current length of the bit vector. More...
 
size_t count () const
 Returns the number of bits set. More...
 
bool intersects (const Bits &bits) const
 Returns true if the bit vector intersects with the given bits, false if the bit vectors are disjoint. More...
 
bool contains (const Bits &bits) const
 Returns true if the given bits are a subset of the bit vector, i.e. for each bit in bits, the corresponding bit in the bit vector is set. More...
 
size_t find_first (size_t n=0) const
 Returns the position of the first bit set in the bit vector, or Bits::npos if none. More...
 
size_t find_next (size_t n) const
 Returns the next position of a bit set in the bit vector, or Bits::npos if none. More...
 
void swap (Bits &bits)
 Swap bit vectors. More...
 

Static Public Attributes

static const size_t npos = static_cast<size_t>(-1)
 

Private Member Functions

void alloc (size_t len)
 On-demand allocator. More...
 

Private Attributes

size_t len_
 number of words More...
 
uint64_t * vec_
 array of words More...
 

Detailed Description

RE/flex Bits class for dynamic bit vectors.

Dynamic bit vectors are stored in Bits objects, which can be manipulated with the usual bit-operations (| (bitor), & (bitand), ^ (bitxor)).

Example:

reflex::Bits digit('0', '9'); // bits '0' (48th bit) to '9' (57th bit)
reflex::Bits upper('A', 'Z'); // bits 'A' (65th bit) to 'Z' (92th bit)
reflex::Bits lower('a', 'z'); // bits 'a' (97th bit) to 'z' (122th bit)
if (upper.intersects(lower) == false)
std::cout << "upper and lower are disjoint\n";
reflex::Bits alnum = digit | upper | lower;
if (alnum.contains(digit) == true)
std::cout << "digit is a subset of alnum\n";
if (alnum['_'] == false)
std::cout << "_ is not in alnum\n";
alnum['_'] = true;
if (alnum['_'] == true)
std::cout << "_ is in updated alnum\n";
std::cout << alnum.count() << " bits in alnum\n";
for (size_t i = alnum.find_first(); i != reflex::Bits::npos; i = alnum.find_next(i))
std::cout << (char)i;

Output:

upper and lower are disjoint
digit is a subset of alnum
_ is not in alnum
_ is in updated alnum
63 bits in alnum
0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz

Constructor & Destructor Documentation

reflex::Bits::Bits ( )
inline

Construct an empty bit vector.

reflex::Bits::Bits ( const Bits bits)
inline

Copy constructor.

Parameters
bitsbits to copy
reflex::Bits::Bits ( size_t  n)
inline

Construct a bit vector and set n'th bit.

Parameters
nn'th bit to set
reflex::Bits::Bits ( size_t  n1,
size_t  n2 
)
inline

Construct a bit vector and set a range of bits n1'th to n2'th.

Parameters
n1first bit to set
n2last bit to set
reflex::Bits::~Bits ( )
inline

Destroy bits.

Member Function Documentation

bool reflex::Bits::all ( ) const
inline

Returns true if all bits are set.

Returns
true if all bits set, false otherwise.
void reflex::Bits::alloc ( size_t  len)
inlineprivate

On-demand allocator.

Parameters
lennumber of words required
bool reflex::Bits::any ( ) const
inline

Returns true if any bit is set.

Returns
true if any bit set, false if none.
Bits& reflex::Bits::clear ( )
inline

Erase all bits.

Returns
reference to this object.
bool reflex::Bits::contains ( const Bits bits) const
inline

Returns true if the given bits are a subset of the bit vector, i.e. for each bit in bits, the corresponding bit in the bit vector is set.

Returns
true if bits is a subset.
Parameters
bitsbits
size_t reflex::Bits::count ( ) const
inline

Returns the number of bits set.

Returns
number of 1 bits.
Bits& reflex::Bits::erase ( size_t  n)
inline

Erase a bit in the bit vector.

Returns
reference to this object.
Parameters
nn'th bit to erase
Bits& reflex::Bits::erase ( size_t  n1,
size_t  n2 
)
inline

Erase a range of bits in the bit vector.

Returns
reference to this object.
Parameters
n1first bit to erase
n2last bit to erase
size_t reflex::Bits::find_first ( size_t  n = 0) const
inline

Returns the position of the first bit set in the bit vector, or Bits::npos if none.

Returns
first position or Bits::npos.
Parameters
ninternal parameter (do not use)
size_t reflex::Bits::find_next ( size_t  n) const
inline

Returns the next position of a bit set in the bit vector, or Bits::npos if none.

Returns
next position or Bits::npos.
Parameters
nthe current position to search from
Bits& reflex::Bits::flip ( size_t  n)
inline

Flips a bit in the bit vector.

Returns
reference to this object.
Parameters
nn'th bit to flip
Bits& reflex::Bits::flip ( size_t  n1,
size_t  n2 
)
inline

Flip a range of bits in the bit vector.

Returns
reference to this object.
Parameters
n1first bit to flip
n2last bit to flip
Bits& reflex::Bits::flip ( )
inline

Flip all bits.

Returns
reference to this object.
Bits& reflex::Bits::insert ( size_t  n)
inline

Insert and set a bit in the bit vector.

Returns
reference to this object.
Parameters
nn'th bit to set
Bits& reflex::Bits::insert ( size_t  n1,
size_t  n2 
)
inline

Insert and set a range of bits in the bit vector.

Returns
reference to this object.
Parameters
n1first bit to set
n2last bit to set
bool reflex::Bits::intersects ( const Bits bits) const
inline

Returns true if the bit vector intersects with the given bits, false if the bit vectors are disjoint.

Returns
true if bits intersect or false if disjoint.
Parameters
bitsbits
bool reflex::Bits::operator!= ( const Bits bits) const
inline

Returns true if bit vectors are unequal.

Returns
true (unequal) or false (equal).
Parameters
bitsrhs bits
Bits reflex::Bits::operator& ( const Bits bits) const
inline

Bit-and (set intersection) of two bit vectors.

Returns
bit vector of the result.
Parameters
bitsbits
Bits& reflex::Bits::operator&= ( const Bits bits)
inline

Bit-and (set intersection) the bit vector with the given bits.

Returns
reference to this object.
Parameters
bitsbits
Bits reflex::Bits::operator- ( const Bits bits) const
inline

Bit-delete (set minus) of two bit vectors.

Returns
bit vector of the result.
Parameters
bitsbits
Bits& reflex::Bits::operator-= ( const Bits bits)
inline

Bit-delete (set minus) the bit vector with the given bits.

Returns
reference to this object.
Parameters
bitsbits
bool reflex::Bits::operator< ( const Bits bits) const
inline

Returns true if the bit vector is lexicographically less than the given right-hand side bits.

Returns
true (less) or false (greater-or-equal).
Parameters
bitsrhs bits
bool reflex::Bits::operator<= ( const Bits bits) const
inline

Returns true if the bit vector is lexicographically less-or-equal to the given right-hand side bits.

Returns
true (less-or-equal) or false (greater).
Parameters
bitsrhs bits
Bits& reflex::Bits::operator= ( const Bits bits)
inline

Assign bits.

Returns
reference to this object.
Parameters
bitsbits to copy
bool reflex::Bits::operator== ( const Bits bits) const
inline

Returns true if bit vectors are equal.

Returns
true (equal) or false (unequal).
Parameters
bitsrhs bits
bool reflex::Bits::operator> ( const Bits bits) const
inline

Returns true if the bit vector is lexicographically greater than the given right-hand side bits.

Returns
true (greater) or false (less-or-equal).
Parameters
bitsrhs bits
bool reflex::Bits::operator>= ( const Bits bits) const
inline

Returns true if the bit vector is lexicographically greater-or-equal to the given right-hand side bits.

Returns
true (greater-or-equal) or false (less).
Parameters
bitsrhs bits
Bitref reflex::Bits::operator[] ( size_t  n)
inline

Reference n'th bit in the bit vector to assign a value to that bit.

Returns
bit reference to assign.
Parameters
nn'th bit
bool reflex::Bits::operator[] ( size_t  n) const
inline

Returns n'th bit.

Returns
true if n'th bit is set, false otherwise.
Parameters
nn'th bit to return
Bits reflex::Bits::operator^ ( const Bits bits) const
inline

Bit-xor of two bit vectors.

Returns
bit vector of the result.
Parameters
bitsbits
Bits& reflex::Bits::operator^= ( const Bits bits)
inline

Bit-xor the bit vector with the given bits.

Returns
reference to this object.
Parameters
bitsbits
Bits reflex::Bits::operator| ( const Bits bits) const
inline

Bit-or (set union) of two bit vectors.

Returns
bit vector of the result.
Parameters
bitsbits
Bits& reflex::Bits::operator|= ( const Bits bits)
inline

Bit-or (set union) the bit vector with the given bits.

Returns
reference to this object.
Parameters
bitsbits
Bits reflex::Bits::operator~ ( ) const
inline

Complement of the bit vector with all bits flipped.

Returns
bit vector of the result.
Bits& reflex::Bits::reserve ( size_t  len)
inline

Reserves space in the bit vector for len bits without changing its current content.

Returns
reference to this object.
Parameters
lennumber of bits to reserve
size_t reflex::Bits::size ( ) const
inline

Returns the current length of the bit vector.

Returns
number of bits.
void reflex::Bits::swap ( Bits bits)
inline

Swap bit vectors.

Parameters
bitsbits

Member Data Documentation

size_t reflex::Bits::len_
private

number of words

const size_t reflex::Bits::npos = static_cast<size_t>(-1)
static

npos returned by find_first() and find_next()

uint64_t* reflex::Bits::vec_
private

array of words


The documentation for this class was generated from the following file: