Clasp::Literal Class Reference

A literal is a variable or its negation. More...

#include <literal.h>

List of all members.

Public Member Functions
uint32 &	asUint ()
uint32	asUint () const
void	clearWatch ()
	Clears the watched-flag of this literal.
uint32	index () const
	Returns the unique index of this literal.
	Literal ()
	The default constructor creates the positive literal of the special sentinel var.
	Literal (Var var, bool sign)
	Creates a literal of the variable var with sign s.
bool	operator== (const Literal &rhs) const
	Equality-Comparison for literals.
Literal	operator~ () const
	Returns the complimentary literal of this literal.
bool	sign () const
	Returns the sign of the literal.
void	swap (Literal &other)
Var	var () const
	Returns the variable of the literal.
void	watch ()
	Sets the watched-flag of this literal.
bool	watched () const
	Returns true if the watched-flag of this literal is set.
Static Public Member Functions
static Literal	fromIndex (uint32 idx)
	Creates a literal from an index.
static Literal	fromRep (uint32 rep)
	Creates a literal from an unsigned integer.
Private Member Functions
	Literal (uint32 rep)
Private Attributes
uint32	rep_

---

Detailed Description

A literal is a variable or its negation.

A literal is determined by two things: a sign and a variable index.

Implementation:

A literal's state is stored in a single 32-bit integer as follows:

• 30-bits : var-index
• 1-bit : sign, 1 if negative, 0 if positive
• 1-bit : watch-flag

Definition at line 80 of file literal.h.

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Constructor & Destructor Documentation

Clasp::Literal::Literal

(

)

[inline]

The default constructor creates the positive literal of the special sentinel var.

Definition at line 83 of file literal.h.

Clasp::Literal::Literal	(	Var	var,
		bool	sign
	)		[inline]

Creates a literal of the variable var with sign s.

Parameters:

var	The literal's variable.
s	true if new literal should be negative.

Precondition:

var < varMax

Definition at line 91 of file literal.h.

Clasp::Literal::Literal

(

uint32

rep

)

[inline, private]

Definition at line 156 of file literal.h.

---

Member Function Documentation

uint32& Clasp::Literal::asUint

(

)

[inline]

Definition at line 113 of file literal.h.

uint32 Clasp::Literal::asUint

(

)

const [inline]

Definition at line 114 of file literal.h.

void Clasp::Literal::clearWatch

(

)

[inline]

Clears the watched-flag of this literal.

Definition at line 131 of file literal.h.

static Literal Clasp::Literal::fromIndex

(

uint32

idx

)

[inline, static]

Creates a literal from an index.

Precondition:

idx < 2^31

Definition at line 105 of file literal.h.

static Literal Clasp::Literal::fromRep

(

uint32

rep

)

[inline, static]

Creates a literal from an unsigned integer.

Definition at line 111 of file literal.h.

uint32 Clasp::Literal::index

(

)

const [inline]

Returns the unique index of this literal.

Note:

The watch-flag is ignored and thus the index of a literal can be stored in 31-bits.

Definition at line 99 of file literal.h.

bool Clasp::Literal::operator==

(

const Literal &

rhs

)

const [inline]

Equality-Comparison for literals.

Two Literals p and q are equal, iff

• they both refer to the same variable
• they have the same sign

Definition at line 152 of file literal.h.

Literal Clasp::Literal::operator~

(

)

const [inline]

Returns the complimentary literal of this literal.

The complementary Literal of a Literal is a Literal referring to the same variable but with inverted sign.

Definition at line 141 of file literal.h.

bool Clasp::Literal::sign

(

)

const [inline]

Returns the sign of the literal.

Returns:

true if the literal is negative. Otherwise false.

Definition at line 123 of file literal.h.

void Clasp::Literal::swap

(

Literal &

other

)

[inline]

Definition at line 125 of file literal.h.

Var Clasp::Literal::var

(

)

const [inline]

Returns the variable of the literal.

Definition at line 117 of file literal.h.

void Clasp::Literal::watch

(

)

[inline]

Sets the watched-flag of this literal.

Definition at line 128 of file literal.h.

bool Clasp::Literal::watched

(

)

const [inline]

Returns true if the watched-flag of this literal is set.

Definition at line 134 of file literal.h.

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Member Data Documentation

uint32 Clasp::Literal::rep_ [private]

Definition at line 157 of file literal.h.

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

• literal.h