Provided by: tcllib_1.15-dfsg-2_all bug

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 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>