Ubuntu Manpage: struct::graph_v1 - Create and manipulate directed graph objects

NAME

       struct::graph_v1 - Create and manipulate directed graph objects

SYNOPSIS

       package require Tcl  8.2

       package require struct::graph  ?1.2.1?

       graphName option ?arg arg ...?

       graphName destroy

       graphName arc append arc ?-key key? value

       graphName arc delete arc ?arc ...?

       graphName arc exists arc

       graphName arc get arc ?-key key?

       graphName arc getall arc

       graphName arc keys arc

       graphName arc keyexists arc ?-key key?

       graphName arc insert start end ?child?

       graphName arc lappend arc ?-key key? value

       graphName arc set arc ?-key key? ?value?

       graphName arc source arc

       graphName arc target arc

       graphName arc unset arc ?-key key?

       graphName arcs ?-key key? ?-value value? ?-in|-out|-adj|-inner|-embedding nodelist?

       graphName node append node ?-key key? value

       graphName node degree ?-in|-out? node

       graphName node delete node ?node ...?

       graphName node exists node

       graphName node get node ?-key key?

       graphName node getall node

       graphName node keys node

       graphName node keyexists node ?-key key?

       graphName node insert ?child?

       graphName node lappend node ?-key key? value

       graphName node opposite node arc

       graphName node set node ?-key key? ?value?

       graphName node unset node ?-key key?

       graphName nodes ?-key key? ?-value value? ?-in|-out|-adj|-inner|-embedding nodelist?

       graphName get ?-key key?

       graphName getall

       graphName keys

       graphName keyexists ?-key key?

       graphName set ?-key key? ?value?

       graphName swap node1 node2

       graphName unset ?-key key?

       graphName walk node ?-order order? ?-type type? ?-dir direction? -command cmd

_________________________________________________________________________________________________

DESCRIPTION

The ::struct::graph command creates a new graph object with an associated global Tcl
command whose name is graphName. This command may be used to invoke various operations on
the graph. It has the following general form:

graphName option ?arg arg ...?
Option and the args determine the exact behavior of the command.

A directed graph is a structure containing two collections of elements, called nodes and
arcs respectively, together with a relation ("connectivity") that places a general
structure upon the nodes and arcs.

Each arc is connected to two nodes, one of which is called the source and the other the
target. This imposes a direction upon the arc, which is said to go from the source to the
target. It is allowed that source and target of an arc are the same node. Such an arc is
called a loop. Whenever a node is source or target of an arc both are said to be adjacent.
This extends into a relation between nodes, i.e. if two nodes are connected through at
least one arc they are said to be adjacent too.

Each node can be the source and target for any number of arcs. The former are called the
outgoing arcs of the node, the latter the incoming arcs of the node. The number of edges
in either set is called the in- resp. the out-degree of the node.

In addition to maintaining the node and arc relationships, this graph implementation
allows any number of keyed values to be associated with each node and arc.

The following commands are possible for graph objects:

graphName destroy
Destroy the graph, including its storage space and associated command.

graphName arc append arc ?-key key? value
Appends a value to one of the keyed values associated with an arc. If no key is
specified, the key data is assumed.

graphName arc delete arc ?arc ...?
Remove the specified arcs from the graph.

graphName arc exists arc
Return true if the specified arc exists in the graph.

graphName arc get arc ?-key key?
Return the value associated with the key key for the arc. If no key is specified,
the key data is assumed.

graphName arc getall arc
Returns a serialized list of key/value pairs (suitable for use with [array set])
for the arc.

graphName arc keys arc
Returns a list of keys for the arc.

graphName arc keyexists arc ?-key key?
Return true if the specified key exists for the arc. If no key is specified, the
key data is assumed.

graphName arc insert start end ?child?
Insert an arc named child into the graph beginning at the node start and ending at
the node end. If the name of the new arc is not specified the system will generate
a unique name of the form arcx.

graphName arc lappend arc ?-key key? value
Appends a value (as a list) to one of the keyed values associated with an arc. If
no key is specified, the key data is assumed.

graphName arc set arc ?-key key? ?value?
Set or get one of the keyed values associated with an arc. If no key is specified,
the key data is assumed. Each arc that is added to a graph has the empty string
assigned to the key data automatically. An arc may have any number of keyed values
associated with it. If value is not specified, this command returns the current
value assigned to the key; if value is specified, this command assigns that value
to the key.

graphName arc source arc
Return the node the given arc begins at.

graphName arc target arc
Return the node the given arc ends at.

graphName arc unset arc ?-key key?
Remove a keyed value from the arc arc. If no key is specified, the key data is
assumed.

graphName arcs ?-key key? ?-value value? ?-in|-out|-adj|-inner|-embedding nodelist?
Return a list of arcs in the graph. If no restriction is specified a list
containing all arcs is returned. Restrictions can limit the list of returned arcs
based on the nodes that are connected by the arc, on the keyed values associated
with the arc, or both. The restrictions that involve connected nodes have a list of
nodes as argument, specified after the name of the restriction itself.

-in Return a list of all arcs whose target is one of the nodes in the nodelist.

-out Return a list of all arcs whose source is one of the nodes in the nodelist.

-adj Return a list of all arcs adjacent to at least one of the nodes in the
nodelist. This is the union of the nodes returned by -in and -out.

-inner Return a list of all arcs adjacent to two of the nodes in the nodelist. This
is the set of arcs in the subgraph spawned by the specified nodes.

-embedding
Return a list of all arcs adjacent to exactly one of the nodes in the
nodelist. This is the set of arcs connecting the subgraph spawned by the
specified nodes to the rest of the graph.

-key key
Limit the list of arcs that are returned to those arcs that have an
associated key key.

-value value
This restriction can only be used in combination with -key. It limits the
list of arcs that are returned to those arcs whose associated key key has
the value value.

The restrictions imposed by either -in, -out, -adj, -inner, or -embedded are applied
first. Specifying more than one of them is illegal. At last the restrictions set via -key
(and -value) are applied. Specifying more than one -key (and -value) is illegal.

graphName node append node ?-key key? value
Appends a value to one of the keyed values associated with an node. If no key is
specified, the key data is assumed.

graphName node degree ?-in|-out? node
Return the number of arcs adjacent to the specified node. If one of the
restrictions -in or -out is given only the incoming resp. outgoing arcs are
counted.

graphName node delete node ?node ...?
Remove the specified nodes from the graph. All of the nodes' arcs will be removed
as well to prevent unconnected arcs.

graphName node exists node
Return true if the specified node exists in the graph.

graphName node get node ?-key key?
Return the value associated with the key key for the node. If no key is specified,
the key data is assumed.

graphName node getall node
Returns a serialized list of key/value pairs (suitable for use with [array set])
for the node.

graphName node keys node
Returns a list of keys for the node.

graphName node keyexists node ?-key key?
Return true if the specified key exists for the node. If no key is specified, the
key data is assumed.

graphName node insert ?child?
Insert a node named child into the graph. The nodes has no arcs connected to it. If
the name of the new child is not specified the system will generate a unique name
of the form nodex.

graphName node lappend node ?-key key? value
Appends a value (as a list) to one of the keyed values associated with an node. If
no key is specified, the key data is assumed.

graphName node opposite node arc
Return the node at the other end of the specified arc, which has to be adjacent to
the given node.

graphName node set node ?-key key? ?value?
Set or get one of the keyed values associated with a node. If no key is specified,
the key data is assumed. Each node that is added to a graph has the empty string
assigned to the key data automatically. A node may have any number of keyed values
associated with it. If value is not specified, this command returns the current
value assigned to the key; if value is specified, this command assigns that value
to the key.

graphName node unset node ?-key key?
Remove a keyed value from the node node. If no key is specified, the key data is
assumed.

graphName nodes ?-key key? ?-value value? ?-in|-out|-adj|-inner|-embedding nodelist?
Return a list of nodes in the graph. Restrictions can limit the list of returned
nodes based on neighboring nodes, or based on the keyed values associated with the
node. The restrictions that involve neighboring nodes have a list of nodes as
argument, specified after the name of the restriction itself.

The possible restrictions are the same as for method arcs. The set of nodes to
return is computed as the union of all source and target nodes for all the arcs
satisfying the restriction as defined for arcs.

graphName get ?-key key?
Return the value associated with the key key for the graph. If no key is specified,
the key data is assumed.

graphName getall
Returns a serialized list of key/value pairs (suitable for use with [array set])
for the whole graph.

graphName keys
Returns a list of keys for the whole graph.

graphName keyexists ?-key key?
Return true if the specified key exists for the whole graph. If no key is
specified, the key data is assumed.

graphName set ?-key key? ?value?
Set or get one of the keyed values associated with a graph. If no key is specified,
the key data is assumed. Each graph has the empty string assigned to the key data
automatically. A graph may have any number of keyed values associated with it. If
value is not specified, this command returns the current value assigned to the key;
if value is specified, this command assigns that value to the key.

graphName swap node1 node2
Swap the position of node1 and node2 in the graph.

graphName unset ?-key key?
Remove a keyed value from the graph. If no key is specified, the key data is
assumed.

graphName walk node ?-order order? ?-type type? ?-dir direction? -command cmd
Perform a breadth-first or depth-first walk of the graph starting at the node node
going in either the direction of outgoing or opposite to the incoming arcs.

The type of walk, breadth-first or depth-first, is determined by the value of type;
bfs indicates breadth-first, dfs indicates depth-first. Depth-first is the
default.

The order of the walk, pre-order, post-order or both-order is determined by the
value of order; pre indicates pre-order, post indicates post-order, both indicates
both-order. Pre-order is the default. Pre-order walking means that a node is
visited before any of its neighbors (as defined by the direction, see below). Post-
order walking means that a parent is visited after any of its neighbors. Both-order
walking means that a node is visited before and after any of its neighbors. The
combination of a bread-first walk with post- or both-order is illegal.

The direction of the walk is determined by the value of dir; backward indicates the
direction opposite to the incoming arcs, forward indicates the direction of the
outgoing arcs.

As the walk progresses, the command cmd will be evaluated at each node, with the
mode of the call (enter or leave) and values graphName and the name of the current
node appended. For a pre-order walk, all nodes are entered, for a post-order all
nodes are left. In a both-order walk the first visit of a node enters it, the
second visit leaves it.

BUGS, IDEAS, FEEDBACK

       This document, and the package it describes,  will  undoubtedly  contain  bugs  and  other
       problems.   Please  report  such  in  the  category struct :: graph of the Tcllib Trackers
       [http://core.tcl.tk/tcllib/reportlist].  Please also report any ideas for enhancements you
       may have for either package and/or documentation.

       When proposing code changes, please provide unified diffs, i.e the output of diff -u.

       Note further that attachments are strongly preferred over inlined patches. Attachments can
       be made by going to the Edit form of the ticket immediately after its creation,  and  then
       using the left-most button in the secondary navigation bar.

KEYWORDS

       cgraph, graph

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