atlas::descents::DescentStatus Class Reference

Describes the descent status of each simple root for a single representation. More...

#include <descents.h>

Public Types
enum	Value {   ComplexAscent, RealNonparity, ImaginaryTypeI, ImaginaryTypeII,   ImaginaryCompact, ComplexDescent, RealTypeII, RealTypeI }

Public Member Functions
	DescentStatus ()
	~DescentStatus ()
	DescentStatus (const DescentStatus &ds)
DescentStatus &	operator= (const DescentStatus &ds)
Value	operator[] (size_t s) const
	Returns descent status of simple root #s. More...
void	set (size_t s, Value v)
	Sets the descent status of simple root #s to v. More...

Static Public Member Functions
static bool	isDescent (Value v)
	Tests whether Value is 4 through 7. These are the descents. More...
static bool	isDirectRecursion (Value v)
	Tests whether both bits of DirectRecursionMask are set. More...

Private Attributes
unsigned char	d_data [constants::RANK_MAX]
	Value of byte #j specifies the descent status of simple root #j. More...

Static Private Attributes
static const unsigned	ValMask = constants::charBits - 1
static const unsigned	DescentMask = 0x4ul
	Bitwise "and" of Value with this is non-zero if Value is one of ImaginaryCompact, ComplexDescent, RealTypeII, or RealTypeI (numbers 4–7) More...
static const unsigned	DirectRecursionMask = 0x5ul
	Bitwise "and" of Value with this is equal to this if Value is either ComplexDescent (5) or RealTypeI (7) More...

Detailed Description

Describes the descent status of each simple root for a single representation.

There are eight possibilities for the descent status of a representation parameter w.r.t. a simple reflection, so this information could be packed in three bits. However, this would lead to having some packets lie across word boundaries, with the ensuing complications. Four bits is a good choice; here we take the lazy way of using even eight bits, as this makes the reading even a bit easier. We might come back to four at some later change—this should not require a change in user interface.

Member Enumeration Documentation

enum atlas::descents::DescentStatus::Value

Enumerator
ComplexAscent
RealNonparity
ImaginaryTypeI
ImaginaryTypeII
ImaginaryCompact
ComplexDescent
RealTypeII
RealTypeI

Constructor & Destructor Documentation

atlas::descents::DescentStatus::DescentStatus ( )

inline

atlas::descents::DescentStatus::~DescentStatus ( )

inline

atlas::descents::DescentStatus::DescentStatus ( const DescentStatus &  ds )

inline

Member Function Documentation

static bool atlas::descents::DescentStatus::isDescent ( Value  v )

inlinestatic

Tests whether Value is 4 through 7. These are the descents.

The simple roots passing this test comprise the tau invariant for the representation.

static bool atlas::descents::DescentStatus::isDirectRecursion ( Value  v )

inlinestatic

Tests whether both bits of DirectRecursionMask are set.

In the case of a complex descent or a real type I descent there is a simple recursion formula for the KL element.

DescentStatus& atlas::descents::DescentStatus::operator= ( const DescentStatus &  ds )

inline

Value atlas::descents::DescentStatus::operator[] ( size_t  s ) const

inline

Returns descent status of simple root #s.

void atlas::descents::DescentStatus::set ( size_t  s, Value  v  )

inline

Sets the descent status of simple root #s to v.

Member Data Documentation

unsigned char atlas::descents::DescentStatus::d_data[constants::RANK_MAX]

private

Value of byte #j specifies the descent status of simple root #j.

Value should be 0 through 7; values 0 through 3 are ascents, and 4 through 7 are descents.

const unsigned atlas::descents::DescentStatus::DescentMask = 0x4ul

staticprivate

Bitwise "and" of Value with this is non-zero if Value is one of ImaginaryCompact, ComplexDescent, RealTypeII, or RealTypeI (numbers 4–7)

const unsigned atlas::descents::DescentStatus::DirectRecursionMask = 0x5ul

staticprivate

Bitwise "and" of Value with this is equal to this if Value is either ComplexDescent (5) or RealTypeI (7)

const unsigned atlas::descents::DescentStatus::ValMask = constants::charBits - 1

staticprivate

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

• /home/ran/atlas_project/latest_branch_07182016/sources/gkmod/descents.h