_GHom Class Reference

The concrete data class for Homomorphisms. More...

#include <Hom.h>

Inheritance diagram for _GHom:

Collaboration diagram for _GHom:

Public Member Functions
GDDD	has_image_skip (const GDDD &) const
virtual bool	skip_variable (int) const
	The skip_variable predicate indicates which variables are "don't care" with respect to this SHom. More...
virtual bool	is_selector () const
	The isSelector predicate indicates a homomorphism that only selects paths in the SDD (no modifications, no additions) Tagging with isSelector() allows to enable optimizations and makes the homomorphism eligible as "condition" in ITE construct. More...
virtual const GHom::range_t	get_range () const
	The range returns the dual of skip_variable, default implem considers that all variables are affected by this homomorphism. More...
virtual GHom	invert (const GDDD &) const
	returns the predescessor homomorphism, using pot to determine variable domains More...
	_GHom (int ref=0, bool im=false)
	Constructor. More...
virtual	~_GHom ()
	Virtual Destructor. Default behavior. More...
virtual bool	operator== (const _GHom &h) const =0
	Comparator. More...
bool	operator< (const _GHom &h) const
	Ordering between _GHom. It is the chronological ordering of creation. More...
virtual size_t	hash () const =0
	Hash key computation. More...
virtual _GHom *	clone () const =0
virtual GDDD	eval (const GDDD &) const =0
	The computation function responsible for evaluation over a node. More...
virtual void	mark () const
	For garbage collection. Used in first phase of garbage collection. More...
virtual GDDD	has_image (const GDDD &) const
virtual GHom	negate () const
	returns a negation of a selector homomorphism h, such that h.negate() (d) = d - h(d) More...
virtual GHom	compose (const GHom &r) const
virtual void	print (std::ostream &os) const =0

Static Public Member Functions
static const _GHom *	get_concret (const GHom &ghom)

Private Member Functions
GDDD	eval_skip (const GDDD &) const

Private Attributes
int	refCounter
	For garbage collection. More...
bool	marking
	For garbage collection. More...
bool	immediat
	For operation cache management. More...
size_t	creation_counter
	Counter of objects created (see constructors). More...

Friends
class	GHom
	open access to container class GHom. More...
class	Hom
	open access to container class Hom. More...

Detailed Description

The concrete data class for Homomorphisms.

Users should not use this (private) class directly, but may use it indirectly by deriving user homomorphisms from the StrongHom class.

Constructor & Destructor Documentation

_GHom()

_GHom::_GHom ( int  ref = 0, bool  im = false  )

inline

Constructor.

Note this class is abstract, so this is only used in initialization list of derived classes constructors (hard coded operations and StrongShom).

References creation_counter.

~_GHom()

virtual _GHom::~_GHom ( )

inlinevirtual

Virtual Destructor. Default behavior.

Member Function Documentation

clone()

virtual _GHom* _GHom::clone ( ) const

pure virtual

Implemented in _VarCompVar, _incVar, _setVarConst, _VarCompState, MLHomAdapter, Fixpoint, Minus, RightConcat, LeftConcat, And, Compose, Monotonic, Add, NotCond, Inter, Mult, DomExtract, Apply2k, Constant, and Identity.

compose()

GHom _GHom::compose ( const GHom &  r ) const

virtual

Reimplemented in _VarCompVar, and _VarCompState.

References GHom::id, and GDDD::null.

Referenced by _VarCompState::compose(), _VarCompVar::compose(), and GHom::compose().

eval()

virtual GDDD _GHom::eval ( const GDDD &  ) const

pure virtual

The computation function responsible for evaluation over a node.

Users should not directly use this. Normal behavior is to use GShom::operator() that encapsulates this call with operation caching.

Implemented in MLHomAdapter, Fixpoint, Minus, RightConcat, LeftConcat, And, Compose, Monotonic, Add, NotCond, Inter, Mult, DomExtract, Apply2k, Constant, Identity, and StrongHom.

Referenced by eval_skip(), and GHom::operator()().

eval_skip()

GDDD _GHom::eval_skip ( const GDDD &  d ) const

private

References GDDD::begin(), GDDD::end(), eval(), GHom::id, GDDD::null, GDDD::one, skip_variable(), GDDD::top, and GDDD::variable().

Referenced by GHom::eval().

get_concret()

static const _GHom* _GHom::get_concret ( const GHom &  ghom )

inlinestatic

References GHom::concret.

Referenced by Add::Add(), addCompositionParameter(), _VarCompState::compose(), _VarCompVar::compose(), And::eval(), Fixpoint::eval(), Fixpoint::has_image(), Inter::skip_variable(), NotCond::skip_variable(), Add::skip_variable(), Monotonic::skip_variable(), Compose::skip_variable(), RightConcat::skip_variable(), and Fixpoint::skip_variable().

get_range()

virtual const GHom::range_t _GHom::get_range ( ) const

inlinevirtual

The range returns the dual of skip_variable, default implem considers that all variables are affected by this homomorphism.

Reimplemented in _VarCompVar, _incVar, _setVarConst, _VarCompState, Fixpoint, And, Compose, Monotonic, Add, and NotCond.

References GHom::full_range.

Referenced by GHom::get_range().

has_image()

GDDD _GHom::has_image ( const GDDD &  d ) const

virtual

Reimplemented in Fixpoint, RightConcat, LeftConcat, And, Add, NotCond, Inter, Identity, and StrongHom.

References GHom.

Referenced by Inter::has_image(), And::has_image(), Fixpoint::has_image(), and has_image_skip().

has_image_skip()

GDDD _GHom::has_image_skip

(

const GDDD &

d

)

const

References GDDD::begin(), GDDD::end(), has_image(), GHom::has_image(), GHom::id, GDDD::null, GDDD::one, skip_variable(), GDDD::top, and GDDD::variable().

hash()

virtual size_t _GHom::hash ( ) const

pure virtual

Hash key computation.

It is essential for good hash table operation that the spread of the keys be as good as possible. Also, fast hash key computation is a good design goal. Note that bad hash functions will yield more collisions, thus equality comparisons which may be quite costly.

Implemented in _VarCompVar, _incVar, _setVarConst, _VarCompState, MLHomAdapter, Fixpoint, Minus, RightConcat, LeftConcat, And, Compose, Monotonic, Add, NotCond, Inter, Mult, DomExtract, Apply2k, Constant, and Identity.

invert()

virtual GHom _GHom::invert ( const GDDD &  ) const

inlinevirtual

returns the predescessor homomorphism, using pot to determine variable domains

Reimplemented in _incVar, _setVarConst, Fixpoint, Minus, And, Compose, Monotonic, Add, Inter, Mult, Apply2k, Constant, and Identity.

References GHom, is_selector(), GDDD::null, and print().

Referenced by GHom::invert().

is_selector()

virtual bool _GHom::is_selector ( ) const

inlinevirtual

The isSelector predicate indicates a homomorphism that only selects paths in the SDD (no modifications, no additions) Tagging with isSelector() allows to enable optimizations and makes the homomorphism eligible as "condition" in ITE construct.

Reimplemented in _VarCompVar, _VarCompState, Fixpoint, Minus, And, Compose, Monotonic, Add, NotCond, Inter, Mult, DomExtract, Constant, and Identity.

Referenced by invert(), and GHom::is_selector().

mark()

virtual void _GHom::mark ( ) const

inlinevirtual

For garbage collection. Used in first phase of garbage collection.

Reimplemented in MLHomAdapter, Fixpoint, Minus, RightConcat, LeftConcat, And, Compose, Monotonic, Add, NotCond, Inter, Mult, Apply2k, and Constant.

Referenced by GHom::mark().

negate()

GHom _GHom::negate ( ) const

virtual

returns a negation of a selector homomorphism h, such that h.negate() (d) = d - h(d)

Reimplemented in _VarCompState, And, Add, NotCond, Inter, Constant, and Identity.

References GHom.

Referenced by GHom::negate().

operator<()

bool _GHom::operator<

(

const _GHom &

h

)

const

Ordering between _GHom. It is the chronological ordering of creation.

References creation_counter.

operator==()

virtual bool _GHom::operator== ( const _GHom &  h ) const

pure virtual

Comparator.

Used in case of hash collision. Should be appropriately defined in derived classes, in particular in user defined homomorphisms.

Implemented in NotCond, DomExtract, MLHomAdapter, StrongHom, Fixpoint, Minus, RightConcat, LeftConcat, And, Compose, Monotonic, Add, Inter, Mult, Apply2k, Constant, and Identity.

print()

virtual void _GHom::print ( std::ostream &  os ) const

pure virtual

Implemented in _VarCompVar, _incVar, _setVarConst, _VarCompState, StrongHom, MLHomAdapter, Fixpoint, Minus, RightConcat, LeftConcat, And, Compose, Monotonic, Add, NotCond, Inter, Mult, DomExtract, Apply2k, Constant, and Identity.

Referenced by invert().

skip_variable()

virtual bool _GHom::skip_variable ( int  ) const

inlinevirtual

The skip_variable predicate indicates which variables are "don't care" with respect to this SHom.

This is defined as a StrongHom with : phi(var,val) { if ( skip_variable(var) ) return GShom( var, val, this ); else { real behavior } }

Reimplemented in Identity, _VarCompVar, _setVarConst, _VarCompState, _incVar, Fixpoint, RightConcat, And, Compose, Monotonic, Add, NotCond, Inter, and DomExtract.

Referenced by eval_skip(), has_image_skip(), Inter::skip_variable(), NotCond::skip_variable(), Add::skip_variable(), Monotonic::skip_variable(), Compose::skip_variable(), RightConcat::skip_variable(), Fixpoint::skip_variable(), and GHom::skip_variable().

Friends And Related Function Documentation

GHom

friend class GHom

friend

open access to container class GHom.

Referenced by DomExtract::eval(), has_image(), invert(), Compose::invert(), Identity::negate(), negate(), _VarCompState::phi(), _setVarConst::phi(), _incVar::phi(), and _VarCompVar::phi().

Hom

friend class Hom

friend

open access to container class Hom.

Referenced by Fixpoint::eval().

Member Data Documentation

creation_counter

size_t _GHom::creation_counter

private

Counter of objects created (see constructors).

This is used for the ordering between homomorphisms.

Referenced by _GHom(), and operator<().

immediat

bool _GHom::immediat

mutableprivate

For operation cache management.

If immediat==true, eval is called without attempting a cache hit. Currently only the constant homomorphism has this attribute set to true.

Referenced by GHom::operator()().

marking

bool _GHom::marking

mutableprivate

For garbage collection.

Used in the two phase garbage collection process. A Hom that is not marked after the first pass over the unicity table, will be sweeped in the second phase. Outside of garbage collection routine, marking should always bear the value false.

Referenced by GHom::garbage(), and GHom::mark().

refCounter

int _GHom::refCounter

mutableprivate

For garbage collection.

Counts the number of times a _GShom is referenced from the context of an Shom.

Referenced by Hom::Hom(), Hom::operator=(), GHom::refCounter(), and Hom::~Hom().

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

• Hom.h
• Hom.cpp