Represents a packet of information that may be individually edited or operated upon. More...

#include <packet/packet.h>

Inheritance diagram for regina::Packet:

Classes
class	ChangeEventSpan
	An object that facilitates firing packetToBeChanged() and packetWasChanged() events. More...

Public Member Functions
std::string	str () const
	Returns a short text representation of this object. More...

std::string	utf8 () const
	Returns a short text representation of this object using unicode characters. More...

std::string	detail () const
	Returns a detailed text representation of this object. More...

Constructors and Destructors
virtual	~Packet ()
	Destroys this packet. More...

Packet Identification
virtual PacketType	type () const =0
	Returns the unique integer ID representing this type of packet. More...

virtual std::string	typeName () const =0
	Returns an English name for this type of packet. More...

const std::string &	label () const
	Returns the label associated with this individual packet. More...

std::string	humanLabel () const
	Returns the label associated with this individual packet, adjusted if necessary for human-readable output. More...

std::string	adornedLabel (const std::string &adornment) const
	Returns the label of this packet adorned with the given string. More...

void	setLabel (const std::string &label)
	Sets the label associated with this individual packet. More...

std::string	fullName () const
	Returns a descriptive text string for the packet. More...

Tags
bool	hasTag (const std::string &tag) const
	Determines whether this packet has the given associated tag. More...

bool	hasTags () const
	Determines whether this packet has any associated tags at all. More...

bool	addTag (const std::string &tag)
	Associates the given tag with this packet. More...

bool	removeTag (const std::string &tag)
	Removes the association of the given tag with this packet. More...

void	removeAllTags ()
	Removes all associated tags from this packet. More...

const std::set< std::string > &	tags () const
	Returns the set of all tags associated with this packet. More...

Event Handling
bool	listen (PacketListener *listener)
	Registers the given packet listener to listen for events on this packet. More...

bool	isListening (PacketListener *listener)
	Determines whether the given packet listener is currently listening for events on this packet. More...

bool	unlisten (PacketListener *listener)
	Unregisters the given packet listener so that it no longer listens for events on this packet. More...

Tree Queries
bool	samePacket (const Packet &other) const
	Determines whether this and the given object refer to the same packet. More...

bool	hasParent () const
	Determines if this packet has a parent in the tree structure. More...

std::shared_ptr< Packet >	parent () const
	Determines the parent packet in the tree structure. More...

std::shared_ptr< Packet >	firstChild () const
	Determines the first child of this packet in the tree structure. More...

std::shared_ptr< Packet >	lastChild () const
	Determines the last child of this packet in the tree structure. More...

std::shared_ptr< Packet >	nextSibling () const
	Determines the next sibling of this packet in the tree structure. More...

std::shared_ptr< Packet >	prevSibling () const
	Determines the previous sibling of this packet in the tree structure. More...

std::shared_ptr< Packet >	root () const
	Determines the root of the tree to which this packet belongs. More...

unsigned	levelsDownTo (const Packet &descendant) const
	Counts the number of levels between this packet and its given descendant in the tree structure. More...

unsigned	levelsUpTo (const Packet &ancestor) const
	Counts the number of levels between this packet and its given ancestor in the tree structure. More...

bool	isAncestorOf (const Packet &descendant) const
	Determines if this packet is equal to or an ancestor of the given packet in the tree structure. More...

size_t	countChildren () const
	Returns the number of immediate children of this packet. More...

size_t	countDescendants () const
	Returns the total number of strict descendants of this packet. More...

size_t	totalTreeSize () const
	Determines the total number of packets in the tree or subtree for which this packet is matriarch. More...

Tree Manipulation
void	prepend (std::shared_ptr< Packet > child)
	Inserts the given packet as the first child of this packet. More...

void	insertChildFirst (std::shared_ptr< Packet > child)
	Deprecated routine that inserts the given packet as the first child of this packet. More...

void	append (std::shared_ptr< Packet > child)
	Inserts the given packet as the last child of this packet. More...

void	insertChildLast (std::shared_ptr< Packet > child)
	Deprecated routine that inserts the given packet as the last child of this packet. More...

void	insert (std::shared_ptr< Packet > newChild, std::shared_ptr< Packet > prevChild)
	Inserts the given packet as a child of this packet at the given location in this packet's child list. More...

void	insertChildAfter (std::shared_ptr< Packet > newChild, std::shared_ptr< Packet > prevChild)
	Deprecated routine that inserts the given packet as a child of this packet at the given location in this packet's child list. More...

void	makeOrphan ()
	Cuts this packet away from its parent in the tree structure and instead makes it the root of its own tree. More...

void	reparent (const std::shared_ptr< Packet > &newParent, bool first=false)
	Cuts this packet away from its parent in the tree structure, and inserts it as a child of the given packet instead. More...

void	transferChildren (const std::shared_ptr< Packet > &newParent)
	Cuts all of this packet's children out of the packet tree, and reinserts them as children of the given packet instead. More...

void	swapWithNextSibling ()
	Swaps this packet with its next sibling in the sequence of children beneath their common parent packet. More...

void	moveUp (unsigned steps=1)
	Moves this packet the given number of steps towards the beginning of its sibling list. More...

void	moveDown (unsigned steps=1)
	Moves this packet the given number of steps towards the end of its sibling list. More...

void	moveToFirst ()
	Moves this packet to be the first in its sibling list. More...

void	moveToLast ()
	Moves this packet to be the last in its sibling list. More...

void	sortChildren ()
	Sorts the immediate children of this packet according to their packet labels. More...

Searching and Iterating
SubtreeIterator< false >	begin ()
	Returns a C++ non-const iterator at the beginning of the range of packets in the subtree rooted at this packet. More...

SubtreeIterator< false >	end ()
	Returns a C++ non-const iterator beyond the end of the range of packets in the subtree rooted at this packet. More...

SubtreeIterator< true >	begin () const
	Returns a C++ const iterator at the beginning of the range of packets in the subtree rooted at this packet. More...

SubtreeIterator< true >	end () const
	Returns a C++ const iterator beyond the end of the range of packets in the subtree rooted at this packet. More...

auto	__iter__ () const
	Returns a Python iterator over the packets in the subtree rooted at this packet. More...

PacketDescendants< false >	descendants ()
	Returns a lightweight object for iterating through all strict descendants of this packet in the packet tree. More...

PacketDescendants< true >	descendants () const
	Returns a lightweight object for iterating through all strict descendants of this packet in the packet tree. More...

PacketChildren< false >	children ()
	Returns a lightweight object for iterating through the immediate children of this packet. More...

PacketChildren< true >	children () const
	Returns a lightweight object for iterating through the immediate children of this packet. More...

std::shared_ptr< Packet >	nextTreePacket ()
	Finds the next packet after this in a complete depth-first iteration of the entire tree structure to which this packet belongs. More...

std::shared_ptr< const Packet >	nextTreePacket () const
	Finds the next packet after this in a complete depth-first iteration of the entire tree structure to which this packet belongs. More...

std::shared_ptr< Packet >	firstTreePacket (PacketType type)
	Finds the first packet of the requested type in a complete depth-first iteration of the tree structure. More...

std::shared_ptr< const Packet >	firstTreePacket (PacketType type) const
	Finds the first packet of the requested type in a complete depth-first iteration of the tree structure. More...

std::shared_ptr< Packet >	nextTreePacket (PacketType type)
	Finds the next packet after this of the requested type in a complete depth-first iteration of the entire tree structure. More...

std::shared_ptr< const Packet >	nextTreePacket (PacketType type) const
	Finds the next packet after this of the requested type in a complete depth-first iteration of the entire tree structure. More...

std::shared_ptr< Packet >	findPacketLabel (const std::string &label)
	Finds the packet with the requested label in the tree or subtree for which this packet is matriarch. More...

std::shared_ptr< const Packet >	findPacketLabel (const std::string &label) const
	Finds the packet with the requested label in the tree or subtree for which this packet is matriarch. More...

Cloning
std::shared_ptr< Packet >	cloneAsSibling (bool cloneDescendants=false, bool end=true) const
	Clones this packet (and possibly its descendants), assigns to it a suitable unused label and inserts the clone into the tree as a sibling of this packet. More...

File I/O
using	PacketRefs = std::map< const Packet *, bool >
	Used during the XML output routines to manage references between packets in an XML data file. More...

template<typename >
class	PacketData

bool	save (const char *filename, bool compressed=true, FileFormat format=REGINA_CURRENT_FILE_FORMAT) const
	Saves the subtree rooted at this packet to the given Regina data file, using Regina's native XML file format. More...

bool	save (std::ostream &s, bool compressed=true, FileFormat format=REGINA_CURRENT_FILE_FORMAT) const
	Writes the subtree rooted at this packet to the given output stream, in the format of a Regina XML data file. More...

void	writeXMLFile (std::ostream &out, FileFormat format=REGINA_CURRENT_FILE_FORMAT) const
	Writes the subtree rooted at this packet to the given output stream in Regina's native XML file format. More...

std::string	internalID () const
	Returns a unique string ID that identifies this packet. More...

virtual void	writeTextShort (std::ostream &out) const =0
	Writes a short text representation of this object to the given output stream. More...

virtual void	writeTextLong (std::ostream &out) const
	Writes a detailed text representation of this object to the given output stream. More...

	Packet ()=default
	Constructor that initialises the packet to have no parent and no children. More...

	Packet (const Packet &)
	Copy constructor that does not actually copy any of the packet infrastructure. More...

Packet &	operator= (const Packet &)
	Assignment operator that does not actually copy any of the packet infrastructure. More...

virtual std::shared_ptr< Packet >	internalClonePacket () const =0
	Makes a new copy of this packet. More...

template<typename... Args>
void	writeXMLHeader (std::ostream &out, const char element, FileFormat format, bool anon, PacketRefs &refs, bool newline, std::pair< const char , Args >... attr) const
	Writes the opening XML tag for this packet. More...

void	writeXMLTreeData (std::ostream &out, FileFormat format, PacketRefs &refs) const
	Writes any generic XML sub-elements for this packet that come from the packet tree. More...

void	writeXMLFooter (std::ostream &out, const char *element, FileFormat format) const
	Writes the closing XML tag for this packet. More...

void	writeXMLAnon (std::ostream &out, FileFormat format, PacketRefs &refs, const Packet &p) const
	Writes the given packet inside its own anonymous block. More...

virtual void	writeXMLPacketData (std::ostream &out, FileFormat format, bool anon, PacketRefs &refs) const =0
	Writes a chunk of XML containing the full subtree with this packet as matriarch. More...

virtual void	addPacketRefs (PacketRefs &refs) const
	Records which other packets this packet refers to within the overall packet tree. More...

Detailed Description

Represents a packet of information that may be individually edited or operated upon.

Packets are stored in a tree structure, with child/parent relationships; the root of the tree represents a complete Regina data file.

There are two types of packets: innate packets, and wrapped packets.

Innate packets are only relevant within the context of a data file. Examples include containers (which are used to organise the packet tree), or scripts (which stores Python code with variables bound to other packets in the tree). Each innate packet type is represented by its own customised subclass of Packet (e.g., Container or Script).
Wrapped packets hold some other type, which can also act as a standalone mathematical object. Examples include packets that hold triangulations, links, and normal surface lists. Each wrapped packet type is represented by a class of the form PacketOf<Held>, where Held is the underlying mathematical type (e.g., Triangulation<3>, Link, or NormalSurfaces).

Since Regina 7.0, packets are always managed by std::shared_ptr. There are no exceptions to this rule. The implication of this are:

Every new packet must be wrapped in a std::shared_ptr immediately after construction. It is recommended that you create new packets using std::make_shared, not new, so you do not forget this. Many of Regina's operations on packets will assume that such a std::shared_ptr exists, and will throw std::bad_weak_ptr exceptions if it does not.
When given an existing raw packet pointer (e.g., as a function argument), you must not wrap it in a new std::shared_ptr. This would lead to two shared pointers "independently" claiming ownership of the packet (which means the packet would be destroyed earlier than expected). If you need to convert a raw Packet* into a std::shared_ptr, you can use the member function shared_from_this() (inherited from std::enable_shared_from_this).

Parent packets own their children, but children do not own their parents. This has the following impliciations for destruction:

If you have a shared pointer to the root of the packet tree, then this will keep the entire packet tree alive.
To destroy a child packet but not its parent, just call makeOrphan() on the child. This will remove the child from the tree, and then destroy the child once your last shared pointer to it goes out of scope.
If you destroy a parent but you are also holding another shared pointer to one of its children, then that child will not be destroyed. It will instead become orphaned, and will become the root of its own (smaller) packet tree.

The old Packet::safeDelete() function has been removed, since you should not be manually destroying packets at all now (instead just wait for the last std::shared_ptr to be destroyed).

There are different requirements when creating a new packet type.

To create a new innate packet type:

Add a new type constant to the PacketType enum;
Add corresponding cases to the routines in PacketInfo;
Create a new subclass C of Packet, which begins with the REGINA_PACKET macro and implements all pure virtual functions (except for those already provided by REGINA_PACKET);
Declare and implement a copy constructor, copy assignment operator, and member/global swap functions, whose arguments use the derived class C (not the base class Packet);
Add an appropriate case to XMLPacketReader::startSubElement(), to support reading from file;
For every routine in C that edits the packet contents, declare a Packet::ChangeEventSpan on the stack while the modification takes place so that listeners are notified (see the discussion below on event listeners).

To create a new wrapped packet type that holds an object of type Held:

Add a new type constant T to the PacketType enum;
Add a specialisation of the template constant packetTypeHolds<Held>, which should take the value T;
Add corresponding cases to the routines in PacketInfo;
Add PacketData<Held> as a new base class for Held (this is very lightweight, just adding a single enum variable);
Add specialisations that implement the routines in XMLWriter<Held>, to support writing to file;
Add an appropriate case to XMLPacketReader::startSubElement(), to support reading from file;
For every routine in Held that edits the packet contents, declare a Held::ChangeEventSpan on the stack while the modification takes place. This is again lightweight (if an object does not belong to a packet then the cost is just two integer comparisions), and it will ensure that if the object does belong to a packet then listeners are notified.

External objects can listen for events on packets, such as when packets are changed or about to be destroyed. This is useful (for example) when keeping a graphical user interface in sync with any changes that might be happening within the engine and/or via users' python scripts. See the PacketListener class notes for details.

Regina's packet types do not support C++ move semantics, since this would interfere with the structure of the packet tree. They do support copy construction, copy assignment and swaps, but only in the derived packet classes (e.g., you cannot assign from the polymorphic base class Packet). Moreover, these operations only copy/swap the mathematical content, not the packet infrastructure (e.g., they do not touch packet labels, or the packet tree, or event listeners).

Member Typedef Documentation

◆ PacketRefs

using regina::Packet::PacketRefs = std::map<const Packet*, bool>

protected

Used during the XML output routines to manage references between packets in an XML data file.

If some packet needs to refer to a packet P, then P will appear as a key this map; the corresponding value will be false initially, and will change to true once P has been written to the XML file.

Constructor & Destructor Documentation

◆ ~Packet()

virtual regina::Packet::~Packet ( )

virtual

Destroys this packet.

Any children of this packet that are still managed by other shared pointers will become orphaned. Any children that are not managed by other shared pointers will be destroyed also.

◆ Packet() [1/2]

regina::Packet::Packet ( )

protecteddefault

Constructor that initialises the packet to have no parent and no children.

◆ Packet() [2/2]

regina::Packet::Packet ( const Packet & )

inlineprotected

Copy constructor that does not actually copy any of the packet infrastructure.

This is provided so that derived classes can use it implicitly in their own copy constructors.

Member Function Documentation

◆ iter()

auto regina::Packet::__iter__ ( ) const

Returns a Python iterator over the packets in the subtree rooted at this packet.

Subtree iteration is depth-first, where a parent packet is always processed before its descendants. In particular, this packet (as the root of the subtree) will be processed first.

In Python, each packet can be treated as an iterable object, with the effect of iterating through the corresponding subtree:

subtree = ...
for p in subtree:
    ...

Regina also supplies Python users with a member function Packet.subtree(), which returns an iterable object. Iterating over Packet.subtree() is exactly the same as iterating the packet itself; the subtree() function is offered because the intention may be clearer for readers.

See also descendants() for iterating through just the strict descendants in the subtree (i.e., excluding this packet itself), and children() for iterating just through the immediate children of this packet (not the full subtree).

C++: Not present. For C++ users, Packet provides the usual begin() and end() functions instead. In particular, you can iterate over a packet subtree in the usual C++ way using a range-based for loop.

Returns: an iterator over the subtree rooted at this packet.

◆ addPacketRefs()

void regina::Packet::addPacketRefs ( PacketRefs & refs ) const

inlineprotectedvirtual

Records which other packets this packet refers to within the overall packet tree.

For each packet p that this packet refers to, this routine should insert the pair (p, false) into the given map.

This will be run before writing the packet tree to an XML data file. By recording that this packet refers to some other packet p, this will ensure that the XML header for p will include an explicit ID that this packet can then refer to.

Later on, as the XML is written, the value refs[p] will be changed from false to true once p has been written.

If your packet requires that the contents of p appear before this packet it the XML data file, then writeXMLPacketData() should check refs to see if p has already been written, and if not, it should write p in a new anonymous block.

It is fine if p does not actually belong to this packet tree. However, in this case writeXMLPacketData() must take responsibility to ensure that p is written to file. This would need to be done via writeXMLAnon(); moreover, as before, it should only be done only after checking refs to ensure this p has not already been written.

The default implementation of this routine does nothing.

Parameters

refs	the map in which any dependencies should be recorded.

Reimplemented in regina::PacketOf< Held >, and regina::Script.

◆ addTag()

bool regina::Packet::addTag ( const std::string & tag )

Associates the given tag with this packet.

Each packet can have an arbitrary set of string tags associated with it. The tags are not used by this calculation engine; the feature is provided for whatever use a developer or user chooses to make of it.

Tags are case-sensitive. Tags associated with a single packet must be distinct, i.e., a particular tag cannot be associated more than once with the same packet.

Precondition: The given tag is not the empty string.

Parameters

tag	the tag to add.

Returns: true if the given tag was successfully added, or false if the given tag was already present beforehand.

◆ adornedLabel()

std::string regina::Packet::adornedLabel ( const std::string & adornment ) const

Returns the label of this packet adorned with the given string.

An adornment typically shows how a packet has been created and/or modified. For instance, the adornment argument might be "Filled", or "Summand #1".

The way in which the packet label is adorned depends upon the label itself (in particular, an empty packet label will be handled in a sensible way). The way in which the packet label is adorned is subject to change in future versions of Regina.

Note that, whilst this routine returns a modified version of the packet label, the label itself will not be permamently changed.

Parameters

adornment the string that will be used to adorn this packet label. The adornment should just be a piece of English, ideally beginning with an upper-case letter. It should not contain any surrounding punctuation such as brackets or a dash (this will be added automatically by this routine as required).

Returns: a copy of the packet label with the given adornment.

◆ append()

void regina::Packet::append ( std::shared_ptr< Packet > child )

Inserts the given packet as the last child of this packet.

This packet will take ownership of child, in the sense that every parent packet stores (either directly or indirectly) a shared_ptr to every one of its descendants in the packet tree.

In Regina 7.0 and earlier, this routine was called insertChildLast().

This routine takes small constant time.

Precondition: The given child has no parent packet.; This packet is not a descendant of the given child.

Exceptions

InvalidArgument The argument child already has a parent packet. Note that, although this tests one of our preconditions, there are other preconditions that are not tested, and for which no exceptions are thrown.

Parameters

child the child to insert.

◆ begin() [1/2]

SubtreeIterator< false > regina::Packet::begin ( )

inline

Returns a C++ non-const iterator at the beginning of the range of packets in the subtree rooted at this packet.

Subtree iteration is depth-first, where a parent packet is always processed before its descendants. In particular, the iterator returned by begin() will always point to this packet itself.

In C++, these begin() and end() routines allow you to iterate through an entire packet subtree using range-based for loops:

std::shared_ptr<Packet> subtree = ...;

for (Packet& p : *subtree) { ... }

regina::Packet::Packet

Packet()=default

Constructor that initialises the packet to have no parent and no children.

Since Regina 7.0, the return type is templated in order to support both const and non-const iteration. It is recommended that you just use auto if you need to store a local copy of the returned iterator.

See also descendants() for iterating through just the strict descendants in the subtree (i.e., excluding this packet itself), and children() for iterating just through the immediate children of this packet (not the full subtree).

Python: Not present. For Python users, Packet implements the Python iterable interface. You can iterate over the packets in a subtree in the usual Python way, by treating the subtree root as you would any native Python container. See iter() for details.

Returns: an iterator at the beginning of this subtree.

◆ begin() [2/2]

SubtreeIterator< true > regina::Packet::begin ( ) const

inline

Returns a C++ const iterator at the beginning of the range of packets in the subtree rooted at this packet.

Subtree iteration is depth-first, where a parent packet is always processed before its descendants. In particular, the iterator returned by begin() will always point to this packet itself.

In C++, these begin() and end() routines allow you to iterate through an entire packet subtree using range-based for loops:

std::shared_ptr<const Packet> subtree = ...;

for (const Packet& p : *subtree) { ... }

Since Regina 7.0, the return type is templated in order to support both const and non-const iteration. It is recommended that you just use auto if you need to store a local copy of the returned iterator.

See also descendants() for iterating through just the strict descendants in the subtree (i.e., excluding this packet itself), and children() for iterating just through the immediate children of this packet (not the full subtree).

Python: Not present. For Python users, Packet implements the Python iterable interface. You can iterate over the packets in a subtree in the usual Python way, by treating the subtree root as you would any native Python container. See iter() for details.

Returns: an iterator at the beginning of this subtree.

◆ children() [1/2]

PacketChildren< false > regina::Packet::children ( )

inline

Returns a lightweight object for iterating through the immediate children of this packet.

This routine allows you to iterate through the immediate children of a given packet using range-based for loops:

std::shared_ptr<Packet> parent = ...;

for (Packet& child : parent->children()) { ... }

regina::Packet::parent

std::shared_ptr< Packet > parent() const

Determines the parent packet in the tree structure.

Definition: packet.h:4051

In Python, this routine returns an iterable object:

parent = ...
for child in parent.children():
    ...

This function returns a lightweight object in the sense that it does not generate a full list of children in advance, but instead just returns a small iterator that visits each child as required. In particular, this routine has small constant time and memory.

Since Regina 7.0, the return type is templated in order to support both const and non-const iteration. It is recommended that you just use auto if you need to store a local copy of the returned object.

See begin() and end(), as well as descendants(), for iterating through the subtree rooted at this packet (not just the immediate children).

Returns: an object for iterating through the children of this packet.

◆ children() [2/2]

PacketChildren< true > regina::Packet::children ( ) const

inline

Returns a lightweight object for iterating through the immediate children of this packet.

This routine allows you to iterate through the immediate children of a given packet using range-based for loops:

std::shared_ptr<const Packet> parent = ...;

for (const Packet& child : parent->children()) { ... }

This function returns a lightweight object in the sense that it does not generate a full list of children in advance, but instead just returns a small iterator that visits each child as required. In particular, this routine has small constant time and memory.

Since Regina 7.0, the return type is templated in order to support both const and non-const iteration. It is recommended that you just use auto if you need to store a local copy of the returned object.

See begin() and end(), as well as descendants(), for iterating through the subtree rooted at this packet (not just the immediate children).

Returns: an object for iterating through the children of this packet.

◆ cloneAsSibling()

std::shared_ptr< Packet > regina::Packet::cloneAsSibling	(	bool	cloneDescendants = `false`,
		bool	end = `true`
	)		const

Clones this packet (and possibly its descendants), assigns to it a suitable unused label and inserts the clone into the tree as a sibling of this packet.

Note that any string tags associated with this packet will not be cloned.

If this packet has no parent in the tree structure, no clone will be created and null will be returned.

In Regina 6.0.1 and earlier, this function was called clone(). It was renamed in Regina 7.0 to emphasise that this is not just a deep copy, and is not guaranteed to succeed.

Note: Since Regina 7.0, if a normal surface/hypersurface or angle structure list is cloned, then the new clone will refer back to the original triangulation, even if we are cloning an entire packet tree. This is because there is no guarantee that the original triangulation was cloned also (it could live outside the cloned subtree, or might not be part of a packet tree at all).

Parameters

cloneDescendants	`true` if the descendants of this packet should also be cloned and inserted as descendants of the new packet. If this is passed as `false` (the default), only this packet will be cloned.
end	`true` if the new packet should be inserted at the end of the parent's list of children (the default), or `false` if the new packet should be inserted as the sibling immediately after this packet.

Returns: the newly inserted packet, or null if this packet has no parent.

◆ countChildren()

size_t regina::Packet::countChildren ( ) const

Returns the number of immediate children of this packet.

Grandchildren and so on are not counted.

Returns: the number of immediate children.

◆ countDescendants()

size_t regina::Packet::countDescendants ( ) const

inline

Returns the total number of strict descendants of this packet.

This includes children, grandchildren and so on. This packet is not included in the count.

Returns: the total number of strict descendants.

◆ descendants() [1/2]

PacketDescendants< false > regina::Packet::descendants ( )

inline

Returns a lightweight object for iterating through all strict descendants of this packet in the packet tree.

The order of iteration is exactly the same as when iterating over the full subtree rooted at this packet (as offered by Packet::begin() and Packet::end()), except that the iteration excludes this packet itself. In particular, the iteration is depth-first, and each packet in the subtree is processed before its own descendants.

This routine allows you to iterate through all strict descendants of a given packet using range-based for loops:

std::shared_ptr<Packet> parent = ...;

for (Packet& desc : parent->descendants()) { ... }

In Python, this routine returns an iterable object:

parent = ...
for desc in parent.descendants():
    ...

This function returns a lightweight object in the sense that it does not generate a full list of descendants in advance, but instead just returns a small iterator that visits each descendant as required. In particular, this routine has small constant time and memory.

Since Regina 7.0, the return type is templated in order to support both const and non-const iteration. It is recommended that you just use auto if you need to store a local copy of the returned object.

See also begin() and end() for iterating through the entire subtree including this packet, and children() for iterating over just this packet's immediate children.

Returns: an object for iterating through the strict descendants of this packet.

◆ descendants() [2/2]

PacketDescendants< true > regina::Packet::descendants ( ) const

inline

Returns a lightweight object for iterating through all strict descendants of this packet in the packet tree.

The order of iteration is exactly the same as when iterating over the full subtree rooted at this packet (as offered by Packet::begin() and Packet::end()), except that the iteration excludes this packet itself. In particular, the iteration is depth-first, and each packet in the subtree is processed before its own descendants.

This routine allows you to iterate through all strict descendants of a given packet using range-based for loops:

std::shared_ptr<const Packet> parent = ...;

for (const Packet& desc : parent->descendants()) { ... }

This function returns a lightweight object in the sense that it does not generate a full list of descendants in advance, but instead just returns a small iterator that visits each descendant as required. In particular, this routine has small constant time and memory.

Since Regina 7.0, the return type is templated in order to support both const and non-const iteration. It is recommended that you just use auto if you need to store a local copy of the returned object.

See also begin() and end() for iterating through the entire subtree including this packet, and children() for iterating over just this packet's immediate children.

Returns: an object for iterating through the strict descendants of this packet.

◆ detail()

std::string regina::Output< Packet , false >::detail ( ) const

inherited

Returns a detailed text representation of this object.

This text may span many lines, and should provide the user with all the information they could want. It should be human-readable, should not contain extremely long lines (which cause problems for users reading the output in a terminal), and should end with a final newline. There are no restrictions on the underlying character set.

Returns: a detailed text representation of this object.

◆ end() [1/2]

SubtreeIterator< false > regina::Packet::end ( )

inline

Returns a C++ non-const iterator beyond the end of the range of packets in the subtree rooted at this packet.

In C++, these begin() and end() routines allow you to iterate through an entire packet subtree using range-based for loops.

See the begin() documentation for further details.

Python: Not present. For Python users, Packet implements the Python iterable interface. You can iterate over the packets in a subtree in the usual Python way, by treating the subtree root as you would any native Python container. See iter() for details.

Returns: an iterator beyond the end of this subtree.

◆ end() [2/2]

SubtreeIterator< true > regina::Packet::end ( ) const

inline

Returns a C++ const iterator beyond the end of the range of packets in the subtree rooted at this packet.

In C++, these begin() and end() routines allow you to iterate through an entire packet subtree using range-based for loops.

See the begin() documentation for further details.

Python: Not present. For Python users, Packet implements the Python iterable interface. You can iterate over the packets in a subtree in the usual Python way, by treating the subtree root as you would any native Python container. See iter() for details.

Returns: an iterator beyond the end of this subtree.

◆ findPacketLabel() [1/2]

std::shared_ptr< Packet > regina::Packet::findPacketLabel ( const std::string & label )

Finds the packet with the requested label in the tree or subtree for which this packet is matriarch.

Note that label comparisons are case sensitive.

Parameters

label the label to search for.

Returns: the packet with the requested label, or null if there is no such packet.

◆ findPacketLabel() [2/2]

std::shared_ptr< const Packet > regina::Packet::findPacketLabel ( const std::string & label ) const

Finds the packet with the requested label in the tree or subtree for which this packet is matriarch.

Note that label comparisons are case sensitive.

Parameters

label the label to search for.

Returns: the packet with the requested label, or null if there is no such packet.

◆ firstChild()

std::shared_ptr< Packet > regina::Packet::firstChild ( ) const

inline

Determines the first child of this packet in the tree structure.

This routine takes small constant time.

Returns: the first child packet, or null if there is none.

◆ firstTreePacket() [1/2]

std::shared_ptr< Packet > regina::Packet::firstTreePacket ( PacketType type )

inline

Finds the first packet of the requested type in a complete depth-first iteration of the tree structure.

Note that this packet must be the matriarch of the entire tree.

A parent packet is always reached before its children. The tree matriarch will be the first packet visited in a complete depth-first iteration.

Parameters

type	the type of packet to search for.

Returns: the first such packet, or null if there are no packets of the requested type.

◆ firstTreePacket() [2/2]

std::shared_ptr< const Packet > regina::Packet::firstTreePacket ( PacketType type ) const

inline

Finds the first packet of the requested type in a complete depth-first iteration of the tree structure.

Note that this packet must be the matriarch of the entire tree.

A parent packet is always reached before its children. The tree matriarch will be the first packet visited in a complete depth-first iteration.

Parameters

type	the type of packet to search for.

Returns: the first such packet, or null if there are no packets of the requested type.

◆ fullName()

std::string regina::Packet::fullName ( ) const

Returns a descriptive text string for the packet.

The string is of the form label (packet-type).

The packet label will be adjusted for human-readable output according to the behaviour of humanLabel().

Returns: the descriptive text string.

◆ hasParent()

bool regina::Packet::hasParent ( ) const

inline

Determines if this packet has a parent in the tree structure.

This is equivalent to, but slightly faster than, testing whether parent() returns a null pointer.

Returns: if and only if this packet has a parent.

◆ hasTag()

bool regina::Packet::hasTag ( const std::string & tag ) const

inline

Determines whether this packet has the given associated tag.

Each packet can have an arbitrary set of string tags associated with it. The tags are not used by this calculation engine; the feature is provided for whatever use a developer or user chooses to make of it.

Tags are case-sensitive. Tags associated with a single packet must be distinct, i.e., a particular tag cannot be associated more than once with the same packet.

Parameters

tag	the tag to search for.

Returns: true if the given tag is found, false otherwise.

◆ hasTags()

bool regina::Packet::hasTags ( ) const

inline

Determines whether this packet has any associated tags at all.

Each packet can have an arbitrary set of string tags associated with it. The tags are not used by this calculation engine; the feature is provided for whatever use a developer or user chooses to make of it.

Tags are case-sensitive. Tags associated with a single packet must be distinct, i.e., a particular tag cannot be associated more than once with the same packet.

Returns: true if this packet has any tags, false otherwise.

◆ humanLabel()

std::string regina::Packet::humanLabel ( ) const

inline

Returns the label associated with this individual packet, adjusted if necessary for human-readable output.

In particular, if the packet has no label assigned then this routine will return "(no label)", not the empty string.

Warning: The method by which this routine adjusts packet labels is subject to change in future versions of Regina.

Returns: this individual packet's label.

◆ insert()

void regina::Packet::insert	(	std::shared_ptr< Packet >	newChild,
		std::shared_ptr< Packet >	prevChild
	)

Inserts the given packet as a child of this packet at the given location in this packet's child list.

This packet will take ownership of child, in the sense that every parent packet stores (either directly or indirectly) a shared_ptr to every one of its descendants in the packet tree.

In Regina 7.0 and earlier, this routine was called insertChildAfter().

This routine takes small constant time.

Precondition: Parameter newChild has no parent packet.; This packet is already the parent of prevChild.; This packet is not a descendant of newChild.

Exceptions

InvalidArgument The argument newChild already has a parent packet, and/or the argument prevChild is non-null and does not have this packet as its parent. Note that, although this tests some of our preconditions, there are other preconditions that are not tested, and for which no exceptions are thrown.

Parameters

newChild	the child to insert.
prevChild	the preexisting child of this packet after which newChild will be inserted, or `null` if newChild is to be the first child of this packet.

◆ insertChildAfter()

void regina::Packet::insertChildAfter	(	std::shared_ptr< Packet >	newChild,
		std::shared_ptr< Packet >	prevChild
	)

inline

Deprecated routine that inserts the given packet as a child of this packet at the given location in this packet's child list.

Deprecated:: This routine has been renamed to insert(). See insert() for further details.

Precondition: Parameter newChild has no parent packet.; This packet is already the parent of prevChild.; This packet is not a descendant of newChild.

Exceptions

InvalidArgument The argument newChild already has a parent packet, and/or the argument prevChild is non-null and does not have this packet as its parent. Note that, although this tests some of our preconditions, there are other preconditions that are not tested, and for which no exceptions are thrown.

Parameters

newChild	the child to insert.
prevChild	the preexisting child of this packet after which newChild will be inserted, or `null` if newChild is to be the first child of this packet.

◆ insertChildFirst()

void regina::Packet::insertChildFirst ( std::shared_ptr< Packet > child )

inline

Deprecated routine that inserts the given packet as the first child of this packet.

Deprecated:: This routine has been renamed to prepend(). See prepend() for further details.

Precondition: The given child has no parent packet.; This packet is not a descendant of the given child.

Exceptions

InvalidArgument The argument child already has a parent packet. Note that, although this tests one of our preconditions, there are other preconditions that are not tested, and for which no exceptions are thrown.

Parameters

child the child to insert.

◆ insertChildLast()

void regina::Packet::insertChildLast ( std::shared_ptr< Packet > child )

inline

Deprecated routine that inserts the given packet as the last child of this packet.

Deprecated:: This routine has been renamed to append(). See append() for further details.

Precondition: The given child has no parent packet.; This packet is not a descendant of the given child.

Exceptions

InvalidArgument The argument child already has a parent packet. Note that, although this tests one of our preconditions, there are other preconditions that are not tested, and for which no exceptions are thrown.

Parameters

child the child to insert.

◆ internalClonePacket()

virtual std::shared_ptr< Packet > regina::Packet::internalClonePacket ( ) const

protectedpure virtual

Makes a new copy of this packet.

This routine should not insert the new packet into the tree structure, clone the packet's associated tags or give the packet a label. It should also not clone any descendants of this packet.

You may assume that the new packet will eventually be inserted into the tree beneath either the same parent as this packet or a clone of that parent.

Returns: the newly created packet.

Implemented in regina::Attachment, regina::Container, regina::PacketOf< Held >, regina::Script, regina::Text, regina::SurfaceFilterCombination, and regina::SurfaceFilterProperties.

◆ internalID()

std::string regina::Packet::internalID ( ) const

Returns a unique string ID that identifies this packet.

The user has no control over this ID, and it is not human readable. It is guaranteed to remain fixed throughout the lifetime of the program for a given packet, and it is guaranteed not to clash with the ID of any other packet.

If you change the contents of a packet, its ID will not change.

If you clone a packet, the new clone will receive a different ID. If you save and then load a packet to/from file, the ID will change. These behaviours are necessary to ensure that IDs remain unique (since, for instance, you could load several copies of the same data file into memory simultaneously).

The ID is implemented as an encoding of the underlying C++ pointer. This encoding is subject to change in later versions of Regina.

Returns: a unique ID that identifies this packet.

◆ isAncestorOf()

bool regina::Packet::isAncestorOf ( const Packet & descendant ) const

Determines if this packet is equal to or an ancestor of the given packet in the tree structure.

Parameters

descendant the other packet whose relationships we are examining.

Returns: true if and only if this packet is equal to or an ancestor of descendant.

◆ isListening()

bool regina::Packet::isListening ( PacketListener * listener )

inline

Determines whether the given packet listener is currently listening for events on this packet.

See the PacketListener class notes for details.

Parameters

listener the listener to search for.

Returns: true if the given listener is currently registered with this packet, or false otherwise.

◆ label()

const std::string & regina::Packet::label ( ) const

inline

Returns the label associated with this individual packet.

An example is MyTriangulation.

Returns: this individual packet's label.

◆ lastChild()

std::shared_ptr< Packet > regina::Packet::lastChild ( ) const

inline

Determines the last child of this packet in the tree structure.

This routine takes small constant time.

Returns: the last child packet, or null if there is none.

◆ levelsDownTo()

unsigned regina::Packet::levelsDownTo ( const Packet & descendant ) const

Counts the number of levels between this packet and its given descendant in the tree structure.

If descendant is this packet, the number of levels is zero.

Precondition: This packet is equal to descendant, or can be obtained from descendant using only child-to-parent steps.

Exceptions

FailedPrecondition The argument descendant is not equal to or a descendant of this packet.

Parameters

descendant the packet whose relationship with this packet we are examining.

Returns: the number of levels difference.

◆ levelsUpTo()

unsigned regina::Packet::levelsUpTo ( const Packet & ancestor ) const

inline

Counts the number of levels between this packet and its given ancestor in the tree structure.

If ancestor is this packet, the number of levels is zero.

Precondition: This packet is equal to ancestor, or can be obtained from ancestor using only parent-to-child steps.

Exceptions

FailedPrecondition This packet is not equal to or a descendant of the argument descendant.

Parameters

ancestor the packet whose relationship with this packet we are examining.

Returns: the number of levels difference.

◆ listen()

bool regina::Packet::listen ( PacketListener * listener )

Registers the given packet listener to listen for events on this packet.

See the PacketListener class notes for details.

Parameters

listener the listener to register.

Returns: true if the given listener was successfully registered, or false if the given listener was already registered beforehand.

◆ makeOrphan()

void regina::Packet::makeOrphan ( )

Cuts this packet away from its parent in the tree structure and instead makes it the root of its own tree.

The tree information for both this packet and its parent will be updated.

The old parent will relinquish ownership of this packet. This means that, even if the old parent remains alive, once the last shared_ptr to this packet is destroyed then this packet itself will be destroyed also.

This makeOrphan() function is the preferred way to "delete" a packet p from a larger packet tree: simply orphan p and then dispose of any outstanding shared pointers to it (if you have any).

Even if you are not holding a shared_ptr to this packet yourself, this routine is still safe to use: it will keep an internal shared_ptr as a "guard" until makeOrphan() has completed its work, at which point the packet will be safely destroyed.

This routine takes small constant time. It is safe to use regardless of whether this packet currently has a parent or not.

◆ moveDown()

void regina::Packet::moveDown ( unsigned steps = 1 )

Moves this packet the given number of steps towards the end of its sibling list.

If the number of steps is larger than the greatest possible movement, the packet will be moved to the very end of its sibling list.

This routine takes time proportional to the number of steps.

Precondition: The given number of steps is strictly positive.

Parameters

steps the number of steps down to move.

◆ moveToFirst()

void regina::Packet::moveToFirst ( )

Moves this packet to be the first in its sibling list.

This routine takes small constant time.

◆ moveToLast()

void regina::Packet::moveToLast ( )

Moves this packet to be the last in its sibling list.

This routine takes small constant time.

◆ moveUp()

void regina::Packet::moveUp ( unsigned steps = 1 )

Moves this packet the given number of steps towards the beginning of its sibling list.

If the number of steps is larger than the greatest possible movement, the packet will be moved to the very beginning of its sibling list.

This routine takes time proportional to the number of steps.

Precondition: The given number of steps is strictly positive.

Parameters

steps the number of steps up to move.

◆ nextSibling()

std::shared_ptr< Packet > regina::Packet::nextSibling ( ) const

inline

Determines the next sibling of this packet in the tree structure.

This is the child of the parent that follows this packet.

This routine takes small constant time.

Returns: the next sibling of this packet, or null if there is none.

◆ nextTreePacket() [1/4]

std::shared_ptr< Packet > regina::Packet::nextTreePacket ( )

Finds the next packet after this in a complete depth-first iteration of the entire tree structure to which this packet belongs.

Note that this packet need not be the tree matriarch.

A parent packet is always reached before its children. The tree matriarch will be the first packet visited in a complete depth-first iteration.

Returns: the next packet, or null if this is the last packet in such an iteration.

◆ nextTreePacket() [2/4]

std::shared_ptr< const Packet > regina::Packet::nextTreePacket ( ) const

Finds the next packet after this in a complete depth-first iteration of the entire tree structure to which this packet belongs.

Note that this packet need not be the tree matriarch.

A parent packet is always reached before its children. The tree matriarch will be the first packet visited in a complete depth-first iteration.

Returns: the next packet, or null if this is the last packet in such an iteration.

◆ nextTreePacket() [3/4]

std::shared_ptr< Packet > regina::Packet::nextTreePacket ( PacketType type )

inline

Finds the next packet after this of the requested type in a complete depth-first iteration of the entire tree structure.

Note that this packet need not be the tree matriarch. The order of tree searching is described in firstTreePacket().

Parameters

type	the type of packet to search for.

Returns: the next such packet, or null if this is the last packet of the requested type in such an iteration.

◆ nextTreePacket() [4/4]

std::shared_ptr< const Packet > regina::Packet::nextTreePacket ( PacketType type ) const

inline

Finds the next packet after this of the requested type in a complete depth-first iteration of the entire tree structure.

Note that this packet need not be the tree matriarch. The order of tree searching is described in firstTreePacket().

Parameters

type	the type of packet to search for.

Returns: the next such packet, or null if this is the last packet of the requested type in such an iteration.

◆ operator=()

Packet & regina::Packet::operator= ( const Packet & )

inlineprotected

Assignment operator that does not actually copy any of the packet infrastructure.

This is provided so that derived classes can use it implicitly in their own assignment operators.

Returns: a reference to this packet.

◆ parent()

std::shared_ptr< Packet > regina::Packet::parent ( ) const

inline

Determines the parent packet in the tree structure.

This routine takes small constant time.

Returns: the parent packet, or null if there is none.

◆ prepend()

void regina::Packet::prepend ( std::shared_ptr< Packet > child )

Inserts the given packet as the first child of this packet.

This packet will take ownership of child, in the sense that every parent packet stores (either directly or indirectly) a shared_ptr to every one of its descendants in the packet tree.

In Regina 7.0 and earlier, this routine was called insertChildFirst().

This routine takes small constant time.

Precondition: The given child has no parent packet.; This packet is not a descendant of the given child.

Exceptions

InvalidArgument The argument child already has a parent packet. Note that, although this tests one of our preconditions, there are other preconditions that are not tested, and for which no exceptions are thrown.

Parameters

child the child to insert.

◆ prevSibling()

std::shared_ptr< Packet > regina::Packet::prevSibling ( ) const

inline

Determines the previous sibling of this packet in the tree structure.

This is the child of the parent that precedes this packet.

This routine takes small constant time.

Returns: the previous sibling of this packet, or null if there is none.

◆ removeAllTags()

void regina::Packet::removeAllTags ( )

Removes all associated tags from this packet.

Each packet can have an arbitrary set of string tags associated with it. The tags are not used by this calculation engine; the feature is provided for whatever use a developer or user chooses to make of it.

Tags are case-sensitive. Tags associated with a single packet must be distinct, i.e., a particular tag cannot be associated more than once with the same packet.

◆ removeTag()

bool regina::Packet::removeTag ( const std::string & tag )

Removes the association of the given tag with this packet.

Each packet can have an arbitrary set of string tags associated with it. The tags are not used by this calculation engine; the feature is provided for whatever use a developer or user chooses to make of it.

Tags are case-sensitive. Tags associated with a single packet must be distinct, i.e., a particular tag cannot be associated more than once with the same packet.

Parameters

tag	the tag to remove.

Returns: true if the given tag was removed, or false if the given tag was not actually associated with this packet.

◆ reparent()

void regina::Packet::reparent	(	const std::shared_ptr< Packet > &	newParent,
		bool	first = `false`
	)

Cuts this packet away from its parent in the tree structure, and inserts it as a child of the given packet instead.

This routine is essentially a combination of makeOrphan() followed by either prepend() or append().

Even if you are not holding a shared_ptr to this packet yourself, this routine is still safe to use: it will maintain a shared_ptr as a "guard" so that this packet is not inadvertently destroyed during the transfer.

You may pass newParent as null, in which case this routine behaves in the same way as makeOrphan() (and is similarly safe to use even if there are no other shared pointers to this packet).

This routine takes small constant time. It is safe to use regardless of whether this packet currently has a parent or not.

If you wish to reparent all of the children of a given packet, see transferChildren() instead.

Precondition: The given parent is not a descendant of this packet.

Parameters

newParent	the new parent of this packet, i.e., the packet beneath which this packet will be inserted.
first	`true` if this packet should be inserted as the first child of the given parent, or `false` (the default) if it should be inserted as the last child.

◆ root()

std::shared_ptr< Packet > regina::Packet::root ( ) const

Determines the root of the tree to which this packet belongs.

Returns: the matriarch of the packet tree.

◆ samePacket()

bool regina::Packet::samePacket ( const Packet & other ) const

inline

Determines whether this and the given object refer to the same packet.

This is exactly the same as testing whether the underlying Packet pointers are equal, and so this routine is unnecessary for C++ users.

Instead, this routine is designed for Python users, since:

the Python keyword is will not work, because there could be many different Python wrappers all pointing to the same C++ object;
the Python equality test (==) will not work, since as of Regina 7.0 this compares objects by value (i.e., it tests whether their contents are equal).

A use case for this function could be (for example) iterating through a packet tree and identifying when a particular known packet has been found.

Parameters

other the packet to compare with this.

Returns: true if and only if this and the given object refer to the same underlying packet.

◆ save() [1/2]

bool regina::Packet::save	(	const char *	filename,
		bool	compressed = `true`,
		FileFormat	format = `REGINA_CURRENT_FILE_FORMAT`
	)		const

Saves the subtree rooted at this packet to the given Regina data file, using Regina's native XML file format.

The XML file may be optionally compressed (Regina can happily read both compressed and uncompressed XML).

This is the preferred way of saving a Regina data file. Typically this will be called from the root of the packet tree, which will save the entire packet tree to file.

Precondition: The given packet does not depend on its parent.

Internationalisation: This routine makes no assumptions about the character encoding used in the given file name, and simply passes it through unchanged to low-level C/C++ file I/O routines. The contents of the file will be written using UTF-8.

Parameters

filename	the pathname of the file to write to.
compressed	`true` if the XML data should be compressed, or `false` if it should be written as plain text.
format	indicates which of Regina's XML file formats to write. You should use the default (REGINA_CURRENT_FILE_FORMAT) unless you need your file to be readable by older versions of Regina. This must not be REGINA_BINARY_GEN_1, which is no longer supported.

Returns: true if and only if the file was successfully written.

◆ save() [2/2]

bool regina::Packet::save	(	std::ostream &	s,
		bool	compressed = `true`,
		FileFormat	format = `REGINA_CURRENT_FILE_FORMAT`
	)		const

Writes the subtree rooted at this packet to the given output stream, in the format of a Regina XML data file.

The data file may be optionally compressed (Regina can happily read both compressed and uncompressed XML).

Typically this will be called from the root of the packet tree, which will write the entire packet tree to the given output stream.

Precondition: The given stream is open for writing.; The given packet does not depend on its parent.

Python: Not present. This is not available in Python to avoid confusion with the filename-based save(). However, if you wish to write a Regina XML data file directly to an open Python file, you can still use writeXMLFile() for this.

Parameters

s	the output stream to which to write.
compressed	`true` if the XML data should be compressed, or `false` if it should be written as plain text.
format	indicates which of Regina's XML file formats to write. You should use the default (REGINA_CURRENT_FILE_FORMAT) unless you need your file to be readable by older versions of Regina. This must not be REGINA_BINARY_GEN_1, which is no longer supported.

Returns: true if and only if the data was successfully written.

◆ setLabel()

void regina::Packet::setLabel ( const std::string & label )

Sets the label associated with this individual packet.

Parameters

label the new label to give this packet.

◆ sortChildren()

void regina::Packet::sortChildren ( )

Sorts the immediate children of this packet according to their packet labels.

Note that this routine is not recursive (for instance, grandchildren will not be sorted within each child packet).

This routine takes quadratic time in the number of immediate children (and it's slow quadratic at that).

◆ str()

std::string regina::Output< Packet , false >::str ( ) const

inherited

Returns a short text representation of this object.

This text should be human-readable, should use plain ASCII characters where possible, and should not contain any newlines.

Within these limits, this short text ouptut should be as information-rich as possible, since in most cases this forms the basis for the Python __str__() and __repr__() functions.

Python: The Python "stringification" function __str__() will use precisely this function, and for most classes the Python __repr__() function will incorporate this into its output.

Returns: a short text representation of this object.

◆ swapWithNextSibling()

void regina::Packet::swapWithNextSibling ( )

Swaps this packet with its next sibling in the sequence of children beneath their common parent packet.

Calling this routine is equivalent to calling moveDown().

This routine takes small constant time.

If this packet has no next sibling then this routine safely does nothing.

◆ tags()

const std::set< std::string > & regina::Packet::tags ( ) const

inline

Returns the set of all tags associated with this packet.

Each packet can have an arbitrary set of string tags associated with it. The tags are not used by this calculation engine; the feature is provided for whatever use a developer or user chooses to make of it.

Tags are case-sensitive. Tags associated with a single packet must be distinct, i.e., a particular tag cannot be associated more than once with the same packet.

Python: This routine returns a python set.

Returns: the set of all tags associated with this packet.

◆ totalTreeSize()

size_t regina::Packet::totalTreeSize ( ) const

Determines the total number of packets in the tree or subtree for which this packet is matriarch.

This packet is included in the count.

Returns: the total tree or subtree size.

◆ transferChildren()

void regina::Packet::transferChildren ( const std::shared_ptr< Packet > & newParent )

Cuts all of this packet's children out of the packet tree, and reinserts them as children of the given packet instead.

The children of this packet will be appended to the end of the new parent's child list, in the same order as they were previously.

This is equivalent to calling reparent() on each child, but should be somewhat faster if there are many children to move.

Even if you are not holding a shared_ptr to any of this packet's children, this routine is still safe to use: it will ensure there is always some shared_ptr to guard against any children being inadvertently destroyed during the transfer.

You may pass newParent as null, in which case this routine is equivalent to calling makeOrphan() on each child (and is similarly safe to use even if there are no other shared pointers to this packet).

Precondition: The given parent is not a descendant of this packet.

Parameters

newParent the new parent beneath which the children will be inserted.

◆ type()

virtual PacketType regina::Packet::type ( ) const

pure virtual

Returns the unique integer ID representing this type of packet.

This is the same for all packets of this class.

Returns: the packet type ID.

◆ typeName()

virtual std::string regina::Packet::typeName ( ) const

pure virtual

Returns an English name for this type of packet.

An example is Triangulation3. This is the same for all packets of this class.

Returns: the packet type name.

◆ unlisten()

bool regina::Packet::unlisten ( PacketListener * listener )

Unregisters the given packet listener so that it no longer listens for events on this packet.

See the PacketListener class notes for details.

Parameters

listener the listener to unregister.

Returns: true if the given listener was successfully unregistered, or false if the given listener was not registered in the first place.

◆ utf8()

std::string regina::Output< Packet , false >::utf8 ( ) const

inherited

Returns a short text representation of this object using unicode characters.

Like str(), this text should be human-readable, should not contain any newlines, and (within these constraints) should be as information-rich as is reasonable.

Unlike str(), this function may use unicode characters to make the output more pleasant to read. The string that is returned will be encoded in UTF-8.

Returns: a short text representation of this object.

◆ writeTextLong()

void regina::Packet::writeTextLong ( std::ostream & out ) const

inlinevirtual

Writes a detailed text representation of this object to the given output stream.

This may be reimplemented by subclasses, but the parent Packet class offers a reasonable default implementation.

Python: Not present. Use detail() instead.

Parameters

out	the output stream to which to write.

Reimplemented in regina::PacketOf< Held >, regina::Script, and regina::Text.

◆ writeTextShort()

virtual void regina::Packet::writeTextShort ( std::ostream & out ) const

pure virtual

Writes a short text representation of this object to the given output stream.

This must be reimplemented by subclasses.

Python: Not present. Use str() instead.

Parameters

out	the output stream to which to write.

Implemented in regina::SurfaceFilterCombination, regina::SurfaceFilterProperties, regina::Attachment, regina::Container, regina::PacketOf< Held >, regina::Script, and regina::Text.

◆ writeXMLAnon()

void regina::Packet::writeXMLAnon	(	std::ostream &	out,
		FileFormat	format,
		PacketRefs &	refs,
		const Packet &	p
	)		const

protected

Writes the given packet inside its own anonymous block.

This could (for example) be called as the first step in writeXMLPacketData() if the packet needs some dependency p to have been explicitly written to file and this has not been done yet.

This function simply creates an anon XML block, and within it calls p.writeXMLPacketData() with the anon argument set to true.

Parameters

out	the output stream to which the anonymous block should be written.
format	indicates which of Regina's XML file formats to write.
refs	manages the necessary references between packets in the XML file; see the PacketRefs documentation for details.
p	the packet to write inside the anonymous block.

◆ writeXMLFile()

void regina::Packet::writeXMLFile	(	std::ostream &	out,
		FileFormat	format = `REGINA_CURRENT_FILE_FORMAT`
	)		const

Writes the subtree rooted at this packet to the given output stream in Regina's native XML file format.

Ths is similar to calling save(), except that (i) the user has a more flexible choice of output stream, and (ii) the XML will always be written in plain text (i.e., it will not be compressed).

If you simply wish to save your data to a file on the filesystem, you should call save() instead.

Typically this will be called from the root of the packet tree, which will write the entire packet tree to the output stream.

Python: The argument out should be an open Python file object.

Parameters

out	the output stream to which the XML data file should be written.
format	indicates which of Regina's XML file formats to write. You should use the default (REGINA_CURRENT_FILE_FORMAT) unless you need your file to be readable by older versions of Regina. This must not be REGINA_BINARY_GEN_1, which is no longer supported.

◆ writeXMLFooter()

void regina::Packet::writeXMLFooter	(	std::ostream &	out,
		const char *	element,
		FileFormat	format
	)		const

protected

Writes the closing XML tag for this packet.

This is typically called at the end of writeXMLPacketData().

There will be no whitespace before the closing XML tag. The tag will be followed by a newline.

Parameters

out	the output stream to which the closing XML tag should be written.
element	the name of the XML tag. If we are writing to the REGINA_XML_GEN_2 format, then this will be ignored (and may be `null`), and the tag name `packet` will be used instead.
format	indicates which of Regina's XML file formats to write.

◆ writeXMLHeader()

template<typename... Args>

void regina::Packet::writeXMLHeader	(	std::ostream &	out,
		const char *	element,
		FileFormat	format,
		bool	anon,
		PacketRefs &	refs,
		bool	newline,
		std::pair< const char *, Args >...	attr
	)		const

protected

Writes the opening XML tag for this packet.

This is typically called at the beginning of writeXMLPacketData().

The generic packet attributes (such as label, id if required, and type / typeid if we are writing to the second-generation format REGINA_XML_GEN_2) will be included.

If we are writing to the third-generation file format or newer, then any additional attributes specified in attr will also be included. If we are writing to the second-generation format REGINA_XML_GEN_2, then attr will be ignored.

If this packet appears as a key in the refs map, or if the anon argument indicates that we are in an anonymous block, then this routine will set refs[this] as true to record that this packet is now being written to XML.

Parameters

out	the output stream to which the opening XML tag should be written.
element	the name of the XML tag. If we are writing to the REGINA_XML_GEN_2 format, then this will be ignored (and may be `null`), and the tag name `packet` will be used instead.
format	indicates which of Regina's XML file formats to write.
anon	`true` if this packet is being written within an anonymous block. If so, then the packet ID will always be written.
refs	manages the necessary references between packets in the XML file; see the PacketRefs documentation for details.
newline	indicates whether the opening XML tag should be followed by a newline. Normally this would be `true`, but if you need to avoid whitespace between the opening XML tag and the packet contents then you should pass `false` instead.
attr	any additional attributes to write to the XML tag; each attribute should a pair of the form (attribute, value). When writing to the REGINA_XML_GEN_2 format, this will be ignored.

◆ writeXMLPacketData()

virtual void regina::Packet::writeXMLPacketData	(	std::ostream &	out,
		FileFormat	format,
		bool	anon,
		PacketRefs &	refs
	)		const

protectedpure virtual

Writes a chunk of XML containing the full subtree with this packet as matriarch.

This should contain:

any anonymous packets that need to be written before this packet (but first check refs to ensure these packets have not already been written);
the packet opening XML tag;
the packet contents;
any packet tags and/or child packets (but only if we are not inside an anonymous block);
a closing XML tag and a final newline.

For native packet types, these five stages are typically implemented using:

optional calls to writeXMLAnon();
a single call to writeXMLHeader();
customised output;
a single call to writeXMLTreeData(), if anon is false;
a single call to writeXMLFooter().

For wrapped packet types that use a PacketOf<Held> wrapper, you should instead just specialise the routines from XMLWriter<Held>. The PacketOf wrapper will take care of the tree-specific code (in particular, it will handle the calls to writeXMLAnon() and writeXMLTreeData()).

The output from this routine is only a piece of XML; it should not be used as a complete XML file. For a complete XML file, see routine writeXMLFile() instead.

Parameters

out	the output stream to which the XML should be written.
format	indicates which of Regina's XML file formats to write.
anon	`true` if this packet is being written within an anonymous block. If so, then the packet ID must be included, and any packet tags and/or child packets must be excluded.
refs	manages the necessary references between packets in the XML file; see the PacketRefs documentation for details.

Implemented in regina::Attachment, regina::Container, regina::PacketOf< Held >, regina::Script, regina::Text, regina::SurfaceFilterCombination, and regina::SurfaceFilterProperties.

◆ writeXMLTreeData()

void regina::Packet::writeXMLTreeData	(	std::ostream &	out,
		FileFormat	format,
		PacketRefs &	refs
	)		const

protected

Writes any generic XML sub-elements for this packet that come from the packet tree.

This is typically called towards the end of writeXMLPacketData(), just before the final call to writeXMLFooter().

The generic sub-elements include Regina's packet tags, as well as any child packets in the packet tree.

There will be no whitespace before the first sub-element (and so if there are no sub-elements at all then this routine will output nothing).

Precondition: This packet is not contained within an anonymous block.

Parameters

out	the output stream to which the closing XML tag should be written.
format	indicates which of Regina's XML file formats to write.
refs	manages the necessary references between packets in the XML file; see the PacketRefs documentation for details.

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

packet/packet.h

Classes

Public Member Functions

File I/O

Detailed Description

Member Typedef Documentation

◆ PacketRefs

Constructor & Destructor Documentation

◆ ~Packet()

◆ Packet() [1/2]

◆ Packet() [2/2]

Member Function Documentation

◆ __iter__()

◆ addPacketRefs()

◆ addTag()

◆ adornedLabel()

◆ append()

◆ begin() [1/2]

◆ begin() [2/2]

◆ children() [1/2]

◆ children() [2/2]

◆ cloneAsSibling()

◆ countChildren()

◆ countDescendants()

◆ descendants() [1/2]

◆ descendants() [2/2]

◆ detail()

◆ end() [1/2]

◆ end() [2/2]

◆ findPacketLabel() [1/2]

◆ findPacketLabel() [2/2]

◆ firstChild()

◆ firstTreePacket() [1/2]

◆ firstTreePacket() [2/2]

◆ fullName()

◆ hasParent()

◆ hasTag()

◆ hasTags()

◆ humanLabel()

◆ insert()

◆ insertChildAfter()

◆ insertChildFirst()

◆ insertChildLast()

◆ internalClonePacket()

◆ internalID()

◆ isAncestorOf()

◆ isListening()

◆ label()

◆ lastChild()

◆ levelsDownTo()

◆ levelsUpTo()

◆ listen()

◆ makeOrphan()

◆ moveDown()

◆ moveToFirst()

◆ moveToLast()

◆ moveUp()

◆ nextSibling()

◆ nextTreePacket() [1/4]

◆ nextTreePacket() [2/4]

◆ nextTreePacket() [3/4]

◆ nextTreePacket() [4/4]

◆ operator=()

◆ parent()

◆ prepend()

◆ prevSibling()

◆ removeAllTags()

◆ removeTag()

◆ reparent()

◆ root()

◆ samePacket()

◆ save() [1/2]

◆ save() [2/2]

◆ setLabel()

◆ sortChildren()

◆ str()

◆ swapWithNextSibling()

◆ tags()

◆ totalTreeSize()

◆ transferChildren()

◆ type()

◆ iter()