struct::graph v1(n)           Tcl Data Structures          struct::graph v1(n)



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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

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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 SF Trackers
       [http://sourceforge.net/tracker/?group_id=12883].  Please also report
       any ideas for enhancements you may have for either package and/or
       documentation.

KEYWORDS
       cgraph, graph

CATEGORY
       Data structures

COPYRIGHT
       Copyright (c) 2002 Andreas Kupries <andreas_kupries@users.sourceforge.net>




struct                               1.2.1                 struct::graph v1(n)
