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







struct::graph v1 - Create and manipulate directed graph
  objects








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












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:



  

  
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:



  

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

  

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

  

  
Remove the specified arcs from the graph.

  

  
Return true if the specified arc exists in the graph.

  

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

  

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

  

  
Returns a list of keys for the arc.

  

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

  

  
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.

  

  
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.

  

  
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.

  

  
Return the node the given arc begins at.

  

  
Return the node the given arc ends at.

  

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

  

  
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.







  

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

  

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

  

  
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.

  

  
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.

  

  
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.

  

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

  

  
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.



  

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

  

  
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.

  

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

  

  
Return true if the specified node exists in the graph.

  

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

  

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

  

  
Returns a list of keys for the node.

  

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

  

  
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.

  

  
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.

  

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

  

  
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.

  

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

  

  
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.

  

  

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

  

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

  

  
Returns a list of keys for the whole graph.

  

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

  

  
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.

  

  
Swap the position of node1 and node2 in the graph.

  

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

  

  
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.

  










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.








cgraph, graph








Data structures








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








  

    1.2.1
    struct