# graph_tcl.tcl --
#
# Implementation of a graph data structure for Tcl.
#
# Copyright (c) 2000-2009,2019 by Andreas Kupries <andreas_kupries@users.sourceforge.net>
# Copyright (c) 2008 by Alejandro Paz <vidriloco@gmail.com>
#
# See the file "license.terms" for information on usage and redistribution
# of this file, and for a DISCLAIMER OF ALL WARRANTIES.
package require Tcl 8.4
package require struct::list
package require struct::set
namespace eval ::struct::graph {
# Data storage in the graph module
# -------------------------------
#
# There's a lot of bits to keep track of for each graph:
# nodes
# node values
# node relationships (arcs)
# arc values
#
# It would quickly become unwieldy to try to keep these in arrays or lists
# within the graph namespace itself. Instead, each graph structure will
# get its own namespace. Each namespace contains:
# node:$node array mapping keys to values for the node $node
# arc:$arc array mapping keys to values for the arc $arc
# inArcs array mapping nodes to the list of incoming arcs
# outArcs array mapping nodes to the list of outgoing arcs
# arcNodes array mapping arcs to the two nodes (start & end)
# counter is used to give a unique name for unnamed graph
variable counter 0
# Only export one command, the one used to instantiate a new graph
namespace export graph_tcl
}
# ::struct::graph::graph_tcl --
#
# Create a new graph with a given name; if no name is given, use
# graphX, where X is a number.
#
# Arguments:
# name name of the graph; if null, generate one.
#
# Results:
# name name of the graph created
proc ::struct::graph::graph_tcl {args} {
variable counter
set src {}
set srctype {}
switch -exact -- [llength [info level 0]] {
1 {
# Missing name, generate one.
incr counter
set name "graph${counter}"
}
2 {
# Standard call. New empty graph.
set name [lindex $args 0]
}
4 {
# Copy construction.
foreach {name as src} $args break
switch -exact -- $as {
= - := - as {
set srctype graph
}
deserialize {
set srctype serial
}
default {
return -code error \
"wrong # args: should be \"struct::graph ?name ?=|:=|as|deserialize source??\""
}
}
}
default {
# Error.
return -code error \
"wrong # args: should be \"struct::graph ?name ?=|:=|as|deserialize source??\""
}
}
# FIRST, qualify the name.
if {![string match "::*" $name]} {
# Get caller's namespace; append :: if not global namespace.
set ns [uplevel 1 [list namespace current]]
if {"::" != $ns} {
append ns "::"
}
set name "$ns$name"
}
if {[llength [info commands $name]]} {
return -code error "command \"$name\" already exists, unable to create graph"
}
# Set up the namespace
namespace eval $name {
# Set up the map for values associated with the graph itself
variable graphAttr
array set graphAttr {}
# Set up the node attribute mapping
variable nodeAttr
array set nodeAttr {}
# Set up the arc attribute mapping
variable arcAttr
array set arcAttr {}
# Set up the map from nodes to the arcs coming to them
variable inArcs
array set inArcs {}
# Set up the map from nodes to the arcs going out from them
variable outArcs
array set outArcs {}
# Set up the map from arcs to the nodes they touch.
variable arcNodes
array set arcNodes {}
# Set up a value for use in creating unique node names
variable nextUnusedNode
set nextUnusedNode 1
# Set up a value for use in creating unique arc names
variable nextUnusedArc
set nextUnusedArc 1
# Set up a counter for use in creating attribute arrays.
variable nextAttr
set nextAttr 0
# Set up a map from arcs to their weights. Note: Only arcs
# which actually have a weight are recorded in the map, to
# keep memory usage down.
variable arcWeight
array set arcWeight {}
}
# Create the command to manipulate the graph
interp alias {} $name {} ::struct::graph::GraphProc $name
# Automatic execution of assignment if a source
# is present.
if {$src != {}} {
switch -exact -- $srctype {
graph {_= $name $src}
serial {_deserialize $name $src}
default {
return -code error \
"Internal error, illegal srctype \"$srctype\""
}
}
}
return $name
}
##########################
# Private functions follow
# ::struct::graph::GraphProc --
#
# Command that processes all graph object commands.
#
# Arguments:
# name name of the graph object to manipulate.
# args command name and args for the command
#
# Results:
# Varies based on command to perform
proc ::struct::graph::GraphProc {name {cmd ""} args} {
# Do minimal args checks here
if { [llength [info level 0]] == 2 } {
return -code error "wrong # args: should be \"$name option ?arg arg ...?\""
}
# Split the args into command and args components
set sub _$cmd
if { [llength [info commands ::struct::graph::$sub]] == 0 } {
set optlist [lsort [info commands ::struct::graph::_*]]
set xlist {}
foreach p $optlist {
set p [namespace tail $p]
if {[string match __* $p]} {continue}
lappend xlist [string range $p 1 end]
}
set optlist [linsert [join $xlist ", "] "end-1" "or"]
return -code error \
"bad option \"$cmd\": must be $optlist"
}
uplevel 1 [linsert $args 0 ::struct::graph::$sub $name]
}
# ::struct::graph::_= --
#
# Assignment operator. Copies the source graph into the
# destination, destroying the original information.
#
# Arguments:
# name Name of the graph object we are copying into.
# source Name of the graph object providing us with the
# data to copy.
#
# Results:
# Nothing.
proc ::struct::graph::_= {name source} {
_deserialize $name [$source serialize]
return
}
# ::struct::graph::_--> --
#
# Reverse assignment operator. Copies this graph into the
# destination, destroying the original information.
#
# Arguments:
# name Name of the graph object to copy
# dest Name of the graph object we are copying to.
#
# Results:
# Nothing.
proc ::struct::graph::_--> {name dest} {
$dest deserialize [_serialize $name]
return
}
# ::struct::graph::_append --
#
# Append a value for an attribute in a graph.
#
# Arguments:
# name name of the graph.
# args key value
#
# Results:
# val value associated with the given key of the given arc
proc ::struct::graph::_append {name key value} {
variable ${name}::graphAttr
return [append graphAttr($key) $value]
}
# ::struct::graph::_lappend --
#
# lappend a value for an attribute in a graph.
#
# Arguments:
# name name of the graph.
# args key value
#
# Results:
# val value associated with the given key of the given arc
proc ::struct::graph::_lappend {name key value} {
variable ${name}::graphAttr
return [lappend graphAttr($key) $value]
}
# ::struct::graph::_arc --
#
# Dispatches the invocation of arc methods to the proper handler
# procedure.
#
# Arguments:
# name name of the graph.
# cmd arc command to invoke
# args arguments to propagate to the handler for the arc command
#
# Results:
# As of the invoked handler.
proc ::struct::graph::_arc {name cmd args} {
# Split the args into command and args components
set sub __arc_$cmd
if { [llength [info commands ::struct::graph::$sub]] == 0 } {
set optlist [lsort [info commands ::struct::graph::__arc_*]]
set xlist {}
foreach p $optlist {
set p [namespace tail $p]
lappend xlist [string range $p 6 end]
}
set optlist [linsert [join $xlist ", "] "end-1" "or"]
return -code error \
"bad option \"$cmd\": must be $optlist"
}
uplevel 1 [linsert $args 0 ::struct::graph::$sub $name]
}
# ::struct::graph::__arc_delete --
#
# Remove an arc from a graph, including all of its values.
#
# Arguments:
# name name of the graph.
# args list of arcs to delete.
#
# Results:
# None.
proc ::struct::graph::__arc_delete {name args} {
if {![llength $args]} {
return {wrong # args: should be "::struct::graph::__arc_delete name arc arc..."}
}
# seen is used to catch duplicate arcs in the args
array set seen {}
foreach arc $args {
if {[info exists seen($arc)]} {
return -code error "arc \"$arc\" does not exist in graph \"$name\""
}
CheckMissingArc $name $arc
set seen($arc) .
}
variable ${name}::inArcs
variable ${name}::outArcs
variable ${name}::arcNodes
variable ${name}::arcAttr
variable ${name}::arcWeight
foreach arc $args {
foreach {source target} $arcNodes($arc) break ; # lassign
unset arcNodes($arc)
if {[info exists arcAttr($arc)]} {
unset ${name}::$arcAttr($arc) ;# Note the double indirection here
unset arcAttr($arc)
}
if {[info exists arcWeight($arc)]} {
unset arcWeight($arc)
}
# Remove arc from the arc lists of source and target nodes.
set index [lsearch -exact $outArcs($source) $arc]
ldelete outArcs($source) $index
set index [lsearch -exact $inArcs($target) $arc]
ldelete inArcs($target) $index
}
return
}
# ::struct::graph::__arc_exists --
#
# Test for existence of a given arc in a graph.
#
# Arguments:
# name name of the graph.
# arc arc to look for.
#
# Results:
# 1 if the arc exists, 0 else.
proc ::struct::graph::__arc_exists {name arc} {
return [info exists ${name}::arcNodes($arc)]
}
# ::struct::graph::__arc_flip --
#
# Exchanges origin and destination node of the specified arc.
#
# Arguments:
# name name of the graph object.
# arc arc to change.
#
# Results:
# None
proc ::struct::graph::__arc_flip {name arc} {
CheckMissingArc $name $arc
variable ${name}::arcNodes
variable ${name}::outArcs
variable ${name}::inArcs
set oldsource [lindex $arcNodes($arc) 0]
set oldtarget [lindex $arcNodes($arc) 1]
if {[string equal $oldsource $oldtarget]} return
set newtarget $oldsource
set newsource $oldtarget
set arcNodes($arc) [lreplace $arcNodes($arc) 0 0 $newsource]
lappend outArcs($newsource) $arc
ldelete outArcs($oldsource) [lsearch -exact $outArcs($oldsource) $arc]
set arcNodes($arc) [lreplace $arcNodes($arc) 1 1 $newtarget]
lappend inArcs($newtarget) $arc
ldelete inArcs($oldtarget) [lsearch -exact $inArcs($oldtarget) $arc]
return
}
# ::struct::graph::__arc_get --
#
# Get a keyed value from an arc in a graph.
#
# Arguments:
# name name of the graph.
# arc arc to query.
# key key to lookup
#
# Results:
# value value associated with the key given.
proc ::struct::graph::__arc_get {name arc key} {
CheckMissingArc $name $arc
variable ${name}::arcAttr
if {![info exists arcAttr($arc)]} {
# No attribute data for this arc, key has to be invalid.
return -code error "invalid key \"$key\" for arc \"$arc\""
}
upvar ${name}::$arcAttr($arc) data
if { ![info exists data($key)] } {
return -code error "invalid key \"$key\" for arc \"$arc\""
}
return $data($key)
}
# ::struct::graph::__arc_getall --
#
# Get a serialized array of key/value pairs from an arc in a graph.
#
# Arguments:
# name name of the graph.
# arc arc to query.
# pattern optional glob pattern to restrict retrieval
#
# Results:
# value serialized array of key/value pairs.
proc ::struct::graph::__arc_getall {name arc {pattern *}} {
CheckMissingArc $name $arc
variable ${name}::arcAttr
if {![info exists arcAttr($arc)]} {
# No attributes ...
return {}
}
upvar ${name}::$arcAttr($arc) data
return [array get data $pattern]
}
# ::struct::graph::__arc_keys --
#
# Get a list of keys for an arc in a graph.
#
# Arguments:
# name name of the graph.
# arc arc to query.
# pattern optional glob pattern to restrict retrieval
#
# Results:
# value value associated with the key given.
proc ::struct::graph::__arc_keys {name arc {pattern *}} {
CheckMissingArc $name $arc
variable ${name}::arcAttr
if {![info exists arcAttr($arc)]} {
# No attributes ...
return {}
}
upvar ${name}::$arcAttr($arc) data
return [array names data $pattern]
}
# ::struct::graph::__arc_keyexists --
#
# Test for existence of a given key for a given arc in a graph.
#
# Arguments:
# name name of the graph.
# arc arc to query.
# key key to lookup
#
# Results:
# 1 if the key exists, 0 else.
proc ::struct::graph::__arc_keyexists {name arc key} {
CheckMissingArc $name $arc
variable ${name}::arcAttr
if {![info exists arcAttr($arc)]} {
# No attribute data for this arc, key cannot exist.
return 0
}
upvar ${name}::$arcAttr($arc) data
return [info exists data($key)]
}
# ::struct::graph::__arc_insert --
#
# Add an arc to a graph.
#
# Arguments:
# name name of the graph.
# source source node of the new arc
# target target node of the new arc
# args arc to insert; must be unique. If none is given,
# the routine will generate a unique node name.
#
# Results:
# arc The name of the new arc.
proc ::struct::graph::__arc_insert {name source target args} {
if { [llength $args] == 0 } {
# No arc name was given; generate a unique one
set arc [__generateUniqueArcName $name]
} elseif { [llength $args] > 1 } {
return {wrong # args: should be "::struct::graph::__arc_insert name source target ?arc?"}
} else {
set arc [lindex $args 0]
}
CheckDuplicateArc $name $arc
CheckMissingNode $name $source {source }
CheckMissingNode $name $target {target }
variable ${name}::inArcs
variable ${name}::outArcs
variable ${name}::arcNodes
# Set up the new arc
set arcNodes($arc) [list $source $target]
# Add this arc to the arc lists of its source resp. target nodes.
lappend outArcs($source) $arc
lappend inArcs($target) $arc
return $arc
}
# ::struct::graph::__arc_rename --
#
# Rename a arc in place.
#
# Arguments:
# name name of the graph.
# arc Name of the arc to rename
# newname The new name of the arc.
#
# Results:
# The new name of the arc.
proc ::struct::graph::__arc_rename {name arc newname} {
CheckMissingArc $name $arc
CheckDuplicateArc $name $newname
set oldname $arc
# Perform the rename in the internal
# data structures.
# - graphAttr - not required, arc independent.
# - nodeAttr - not required, arc independent.
# - counters - not required
variable ${name}::arcAttr
variable ${name}::inArcs
variable ${name}::outArcs
variable ${name}::arcNodes
variable ${name}::arcWeight
# Arc relocation
set arcNodes($newname) [set nodes $arcNodes($oldname)]
unset arcNodes($oldname)
# Update the two nodes ...
foreach {start end} $nodes break
set pos [lsearch -exact $inArcs($end) $oldname]
lset inArcs($end) $pos $newname
set pos [lsearch -exact $outArcs($start) $oldname]
lset outArcs($start) $pos $newname
if {[info exists arcAttr($oldname)]} {
set arcAttr($newname) $arcAttr($oldname)
unset arcAttr($oldname)
}
if {[info exists arcWeight($oldname)]} {
set arcWeight($newname) $arcWeight($oldname)
unset arcWeight($oldname)
}
return $newname
}
# ::struct::graph::__arc_set --
#
# Set or get a value for an arc in a graph.
#
# Arguments:
# name name of the graph.
# arc arc to modify or query.
# key attribute to modify or query
# args ?value?
#
# Results:
# val value associated with the given key of the given arc
proc ::struct::graph::__arc_set {name arc key args} {
if { [llength $args] > 1 } {
return -code error "wrong # args: should be \"$name arc set arc key ?value?\""
}
CheckMissingArc $name $arc
if { [llength $args] > 0 } {
# Setting the value. This may have to create
# the attribute array for this particular
# node
variable ${name}::arcAttr
if {![info exists arcAttr($arc)]} {
# No attribute data for this node,
# so create it as we need it now.
GenAttributeStorage $name arc $arc
}
upvar ${name}::$arcAttr($arc) data
return [set data($key) [lindex $args end]]
} else {
# Getting a value
return [__arc_get $name $arc $key]
}
}
# ::struct::graph::__arc_append --
#
# Append a value for an arc in a graph.
#
# Arguments:
# name name of the graph.
# arc arc to modify or query.
# args key value
#
# Results:
# val value associated with the given key of the given arc
proc ::struct::graph::__arc_append {name arc key value} {
CheckMissingArc $name $arc
variable ${name}::arcAttr
if {![info exists arcAttr($arc)]} {
# No attribute data for this arc,
# so create it as we need it.
GenAttributeStorage $name arc $arc
}
upvar ${name}::$arcAttr($arc) data
return [append data($key) $value]
}
# ::struct::graph::__arc_attr --
#
# Return attribute data for one key and multiple arcs, possibly all.
#
# Arguments:
# name Name of the graph object.
# key Name of the attribute to retrieve.
#
# Results:
# children Dictionary mapping arcs to attribute data.
proc ::struct::graph::__arc_attr {name key args} {
# Syntax:
#
# t attr key
# t attr key -arcs {arclist}
# t attr key -glob arcpattern
# t attr key -regexp arcpattern
variable ${name}::arcAttr
set usage "wrong # args: should be \"[list $name] arc attr key ?-arcs list|-glob pattern|-regexp pattern?\""
if {([llength $args] != 0) && ([llength $args] != 2)} {
return -code error $usage
} elseif {[llength $args] == 0} {
# This automatically restricts the list
# to arcs which can have the attribute
# in question.
set arcs [array names arcAttr]
} else {
# Determine a list of arcs to look at
# based on the chosen restriction.
foreach {mode value} $args break
switch -exact -- $mode {
-arcs {
# This is the only branch where we have to
# perform an explicit restriction to the
# arcs which have attributes.
set arcs {}
foreach n $value {
if {![info exists arcAttr($n)]} continue
lappend arcs $n
}
}
-glob {
set arcs [array names arcAttr $value]
}
-regexp {
set arcs {}
foreach n [array names arcAttr] {
if {![regexp -- $value $n]} continue
lappend arcs $n
}
}
default {
return -code error "bad type \"$mode\": must be -arcs, -glob, or -regexp"
}
}
}
# Without possibly matching arcs
# the result has to be empty.
if {![llength $arcs]} {
return {}
}
# Now locate matching keys and their values.
set result {}
foreach n $arcs {
upvar ${name}::$arcAttr($n) data
if {[info exists data($key)]} {
lappend result $n $data($key)
}
}
return $result
}
# ::struct::graph::__arc_lappend --
#
# lappend a value for an arc in a graph.
#
# Arguments:
# name name of the graph.
# arc arc to modify or query.
# args key value
#
# Results:
# val value associated with the given key of the given arc
proc ::struct::graph::__arc_lappend {name arc key value} {
CheckMissingArc $name $arc
variable ${name}::arcAttr
if {![info exists arcAttr($arc)]} {
# No attribute data for this arc,
# so create it as we need it.
GenAttributeStorage $name arc $arc
}
upvar ${name}::$arcAttr($arc) data
return [lappend data($key) $value]
}
# ::struct::graph::__arc_source --
#
# Return the node at the beginning of the specified arc.
#
# Arguments:
# name name of the graph object.
# arc arc to look up.
#
# Results:
# node name of the node.
proc ::struct::graph::__arc_source {name arc} {
CheckMissingArc $name $arc
variable ${name}::arcNodes
return [lindex $arcNodes($arc) 0]
}
# ::struct::graph::__arc_target --
#
# Return the node at the end of the specified arc.
#
# Arguments:
# name name of the graph object.
# arc arc to look up.
#
# Results:
# node name of the node.
proc ::struct::graph::__arc_target {name arc} {
CheckMissingArc $name $arc
variable ${name}::arcNodes
return [lindex $arcNodes($arc) 1]
}
# ::struct::graph::__arc_nodes --
#
# Return a list containing both source and target nodes of the arc.
#
# Arguments:
# name name of the graph object.
# arc arc to look up.
#
# Results:
# nodes list containing the names of the connected nodes node.
# None
proc ::struct::graph::__arc_nodes {name arc} {
CheckMissingArc $name $arc
variable ${name}::arcNodes
return $arcNodes($arc)
}
# ::struct::graph::__arc_move-target --
#
# Change the destination node of the specified arc.
# The arc is rotated around its origin to a different
# node.
#
# Arguments:
# name name of the graph object.
# arc arc to change.
# newtarget new destination/target of the arc.
#
# Results:
# None
proc ::struct::graph::__arc_move-target {name arc newtarget} {
CheckMissingArc $name $arc
CheckMissingNode $name $newtarget
variable ${name}::arcNodes
variable ${name}::inArcs
set oldtarget [lindex $arcNodes($arc) 1]
if {[string equal $oldtarget $newtarget]} return
set arcNodes($arc) [lreplace $arcNodes($arc) 1 1 $newtarget]
lappend inArcs($newtarget) $arc
ldelete inArcs($oldtarget) [lsearch -exact $inArcs($oldtarget) $arc]
return
}
# ::struct::graph::__arc_move-source --
#
# Change the origin node of the specified arc.
# The arc is rotated around its destination to a different
# node.
#
# Arguments:
# name name of the graph object.
# arc arc to change.
# newsource new origin/source of the arc.
#
# Results:
# None
proc ::struct::graph::__arc_move-source {name arc newsource} {
CheckMissingArc $name $arc
CheckMissingNode $name $newsource
variable ${name}::arcNodes
variable ${name}::outArcs
set oldsource [lindex $arcNodes($arc) 0]
if {[string equal $oldsource $newsource]} return
set arcNodes($arc) [lreplace $arcNodes($arc) 0 0 $newsource]
lappend outArcs($newsource) $arc
ldelete outArcs($oldsource) [lsearch -exact $outArcs($oldsource) $arc]
return
}
# ::struct::graph::__arc_move --
#
# Changes both origin and destination node of the specified arc.
#
# Arguments:
# name name of the graph object.
# arc arc to change.
# newsource new origin/source of the arc.
# newtarget new destination/target of the arc.
#
# Results:
# None
proc ::struct::graph::__arc_move {name arc newsource newtarget} {
CheckMissingArc $name $arc
CheckMissingNode $name $newsource
CheckMissingNode $name $newtarget
variable ${name}::arcNodes
variable ${name}::outArcs
variable ${name}::inArcs
set oldsource [lindex $arcNodes($arc) 0]
if {![string equal $oldsource $newsource]} {
set arcNodes($arc) [lreplace $arcNodes($arc) 0 0 $newsource]
lappend outArcs($newsource) $arc
ldelete outArcs($oldsource) [lsearch -exact $outArcs($oldsource) $arc]
}
set oldtarget [lindex $arcNodes($arc) 1]
if {![string equal $oldtarget $newtarget]} {
set arcNodes($arc) [lreplace $arcNodes($arc) 1 1 $newtarget]
lappend inArcs($newtarget) $arc
ldelete inArcs($oldtarget) [lsearch -exact $inArcs($oldtarget) $arc]
}
return
}
# ::struct::graph::__arc_unset --
#
# Remove a keyed value from a arc.
#
# Arguments:
# name name of the graph.
# arc arc to modify.
# key attribute to remove
#
# Results:
# None.
proc ::struct::graph::__arc_unset {name arc key} {
CheckMissingArc $name $arc
variable ${name}::arcAttr
if {![info exists arcAttr($arc)]} {
# No attribute data for this arc,
# nothing to do.
return
}
upvar ${name}::$arcAttr($arc) data
catch {unset data($key)}
if {[array size data] == 0} {
# No attributes stored for this arc, squash the whole array.
unset arcAttr($arc)
unset data
}
return
}
# ::struct::graph::__arc_getunweighted --
#
# Return the arcs which have no weight defined.
#
# Arguments:
# name name of the graph.
#
# Results:
# arcs list of arcs without weights.
proc ::struct::graph::__arc_getunweighted {name} {
variable ${name}::arcNodes
variable ${name}::arcWeight
return [struct::set difference \
[array names arcNodes] \
[array names arcWeight]]
}
# ::struct::graph::__arc_getweight --
#
# Get the weight given to an arc in a graph.
# Throws an error if the arc has no weight defined for it.
#
# Arguments:
# name name of the graph.
# arc arc to query.
#
# Results:
# weight The weight defined for the arc.
proc ::struct::graph::__arc_getweight {name arc} {
CheckMissingArc $name $arc
variable ${name}::arcWeight
if {![info exists arcWeight($arc)]} {
return -code error "arc \"$arc\" has no weight"
}
return $arcWeight($arc)
}
# ::struct::graph::__arc_setunweighted --
#
# Define a weight for all arcs which have no weight defined.
# After this call no arc will be unweighted.
#
# Arguments:
# name name of the graph.
# defval weight to give to all unweighted arcs
#
# Results:
# None
proc ::struct::graph::__arc_setunweighted {name {weight 0}} {
variable ${name}::arcWeight
foreach arc [__arc_getunweighted $name] {
set arcWeight($arc) $weight
}
return
}
# ::struct::graph::__arc_setweight --
#
# Define a weight for an arc.
#
# Arguments:
# name name of the graph.
# arc arc to modify
# weight the weight to set for the arc
#
# Results:
# weight The new weight
proc ::struct::graph::__arc_setweight {name arc weight} {
CheckMissingArc $name $arc
variable ${name}::arcWeight
set arcWeight($arc) $weight
return $weight
}
# ::struct::graph::__arc_unsetweight --
#
# Remove the weight for an arc.
#
# Arguments:
# name name of the graph.
# arc arc to modify
#
# Results:
# None.
proc ::struct::graph::__arc_unsetweight {name arc} {
CheckMissingArc $name $arc
variable ${name}::arcWeight
if {[info exists arcWeight($arc)]} {
unset arcWeight($arc)
}
return
}
# ::struct::graph::__arc_hasweight --
#
# Remove the weight for an arc.
#
# Arguments:
# name name of the graph.
# arc arc to modify
#
# Results:
# None.
proc ::struct::graph::__arc_hasweight {name arc} {
CheckMissingArc $name $arc
variable ${name}::arcWeight
return [info exists arcWeight($arc)]
}
# ::struct::graph::__arc_weights --
#
# Return the arcs and weights for all arcs which have such.
#
# Arguments:
# name name of the graph.
#
# Results:
# aw dictionary mapping arcs to their weights.
proc ::struct::graph::__arc_weights {name} {
variable ${name}::arcWeight
return [array get arcWeight]
}
# ::struct::graph::_arcs --
#
# Return a list of all arcs in a graph satisfying some
# node based restriction.
#
# Arguments:
# name name of the graph.
#
# Results:
# arcs list of arcs
proc ::struct::graph::_arcs {name args} {
CheckE $name arcs $args
switch -exact -- $cond {
none {set arcs [ArcsNONE $name]}
in {set arcs [ArcsIN $name $condNodes]}
out {set arcs [ArcsOUT $name $condNodes]}
adj {set arcs [ArcsADJ $name $condNodes]}
inner {set arcs [ArcsINN $name $condNodes]}
embedding {set arcs [ArcsEMB $name $condNodes]}
default {return -code error "Can't happen, panic"}
}
#
# We have a list of arcs that match the relation to the nodes.
# Now filter according to -key and -value.
#
if {$haveKey && $haveValue} {
set arcs [ArcsKV $name $key $value $arcs]
} elseif {$haveKey} {
set arcs [ArcsK $name $key $arcs]
}
#
# Apply the general filter command, if specified.
#
if {$haveFilter} {
lappend fcmd $name
set arcs [uplevel 1 [list ::struct::list filter $arcs $fcmd]]
}
return $arcs
}
proc ::struct::graph::ArcsIN {name cn} {
# arcs -in. "Arcs going into the node set"
#
# ARC/in (NS) := { a | target(a) in NS }
# The result is all arcs going to at least one node in the set
# 'cn' of nodes.
# As an arc has only one destination, i.e. is the
# in-arc of exactly one node it is impossible to
# count an arc twice. Therefore there is no need
# to keep track of arcs to avoid duplicates.
variable ${name}::inArcs
set arcs {}
foreach node $cn {
foreach e $inArcs($node) {
lappend arcs $e
}
}
return $arcs
}
proc ::struct::graph::ArcsOUT {name cn} {
# arcs -out. "Arcs coming from the node set"
#
# ARC/out (NS) := { a | source(a) in NS }
# The result is all arcs coming from at least one node in the list
# of arguments.
variable ${name}::outArcs
set arcs {}
foreach node $cn {
foreach e $outArcs($node) {
lappend arcs $e
}
}
return $arcs
}
proc ::struct::graph::ArcsADJ {name cn} {
# arcs -adj. "Arcs adjacent to the node set"
#
# ARC/adj (NS) := ARC/in (NS) + ARC/out (NS)
# Result is all arcs coming from or going to at
# least one node in the list of arguments.
return [struct::set union \
[ArcsIN $name $cn] \
[ArcsOUT $name $cn]]
if 0 {
# Alternate implementation using arrays,
# implementing the set union directly,
# intertwined with the data retrieval.
array set coll {}
foreach node $condNodes {
foreach e $inArcs($node) {
if {[info exists coll($e)]} {continue}
lappend arcs $e
set coll($e) .
}
foreach e $outArcs($node) {
if {[info exists coll($e)]} {continue}
lappend arcs $e
set coll($e) .
}
}
}
}
proc ::struct::graph::ArcsINN {name cn} {
# arcs -adj. "Arcs inside the node set"
#
# ARC/inner (NS) := ARC/in (NS) * ARC/out (NS)
# Result is all arcs running between nodes
# in the list.
return [struct::set intersect \
[ArcsIN $name $cn] \
[ArcsOUT $name $cn]]
if 0 {
# Alternate implementation using arrays,
# implementing the set intersection
# directly, intertwined with the data
# retrieval.
array set coll {}
# Here we do need 'coll' as each might be an in- and
# out-arc for one or two nodes in the list of arguments.
array set group {}
foreach node $condNodes {
set group($node) .
}
foreach node $condNodes {
foreach e $inArcs($node) {
set n [lindex $arcNodes($e) 0]
if {![info exists group($n)]} {continue}
if { [info exists coll($e)]} {continue}
lappend arcs $e
set coll($e) .
}
# Second iteration over outgoing arcs not
# required. Any arc found above would be found here as
# well, and arcs not recognized above can't be
# recognized by the out loop either.
}
}
}
proc ::struct::graph::ArcsEMB {name cn} {
# arcs -adj. "Arcs bordering the node set"
#
# ARC/emb (NS) := ARC/inner (NS) - ARC/adj (NS)
# <=> (ARC/in + ARC/out) - (ARC/in * ARC/out)
# <=> (ARC/in - ARC/out) + (ARC/out - ARC/in)
# <=> symmetric difference (ARC/in, ARC/out)
# Result is all arcs from -adj minus the arcs from -inner.
# IOW all arcs going from a node in the list to a node
# which is *not* in the list
return [struct::set symdiff \
[ArcsIN $name $cn] \
[ArcsOUT $name $cn]]
if 0 {
# Alternate implementation using arrays,
# implementing the set intersection
# directly, intertwined with the data
# retrieval.
# This also means that no arc can be counted twice as it
# is either going to a node, or coming from a node in the
# list, but it can't do both, because then it is part of
# -inner, which was excluded!
array set group {}
foreach node $condNodes {
set group($node) .
}
foreach node $condNodes {
foreach e $inArcs($node) {
set n [lindex $arcNodes($e) 0]
if {[info exists group($n)]} {continue}
# if {[info exists coll($e)]} {continue}
lappend arcs $e
# set coll($e) .
}
foreach e $outArcs($node) {
set n [lindex $arcNodes($e) 1]
if {[info exists group($n)]} {continue}
# if {[info exists coll($e)]} {continue}
lappend arcs $e
# set coll($e) .
}
}
}
}
proc ::struct::graph::ArcsNONE {name} {
variable ${name}::arcNodes
return [array names arcNodes]
}
proc ::struct::graph::ArcsKV {name key value arcs} {
set filteredArcs {}
foreach arc $arcs {
catch {
set aval [__arc_get $name $arc $key]
if {$aval == $value} {
lappend filteredArcs $arc
}
}
}
return $filteredArcs
}
proc ::struct::graph::ArcsK {name key arcs} {
set filteredArcs {}
foreach arc $arcs {
catch {
__arc_get $name $arc $key
lappend filteredArcs $arc
}
}
return $filteredArcs
}
# ::struct::graph::_deserialize --
#
# Assignment operator. Copies a serialization into the
# destination, destroying the original information.
#
# Arguments:
# name Name of the graph object we are copying into.
# serial Serialized graph to copy from.
#
# Results:
# Nothing.
proc ::struct::graph::_deserialize {name serial} {
# As we destroy the original graph as part of
# the copying process we don't have to deal
# with issues like node names from the new graph
# interfering with the old ...
# I. Get the serialization of the source graph
# and check it for validity.
CheckSerialization $serial \
gattr nattr aattr ina outa arcn arcw
# Get all the relevant data into the scope
variable ${name}::graphAttr
variable ${name}::nodeAttr
variable ${name}::arcAttr
variable ${name}::inArcs
variable ${name}::outArcs
variable ${name}::arcNodes
variable ${name}::nextAttr
variable ${name}::arcWeight
# Kill the existing information and insert the new
# data in their place.
array unset inArcs *
array unset outArcs *
array set inArcs [array get ina]
array set outArcs [array get outa]
unset ina outa
array unset arcNodes *
array set arcNodes [array get arcn]
unset arcn
array unset arcWeight *
array set arcWeight [array get arcw]
unset arcw
set nextAttr 0
foreach a [array names nodeAttr] {
unset ${name}::$nodeAttr($a)
}
foreach a [array names arcAttr] {
unset ${name}::$arcAttr($a)
}
foreach n [array names nattr] {
GenAttributeStorage $name node $n
array set ${name}::$nodeAttr($n) $nattr($n)
}
foreach a [array names aattr] {
GenAttributeStorage $name arc $a
array set ${name}::$arcAttr($a) $aattr($a)
}
array unset graphAttr *
array set graphAttr $gattr
## Debug ## Dump internals ...
if {0} {
puts "___________________________________ $name"
parray inArcs
parray outArcs
parray arcNodes
parray nodeAttr
parray arcAttr
parray graphAttr
parray arcWeight
puts ___________________________________
}
return
}
# ::struct::graph::_destroy --
#
# Destroy a graph, including its associated command and data storage.
#
# Arguments:
# name name of the graph.
#
# Results:
# None.
proc ::struct::graph::_destroy {name} {
namespace delete $name
interp alias {} $name {}
}
# ::struct::graph::__generateUniqueArcName --
#
# Generate a unique arc name for the given graph.
#
# Arguments:
# name name of the graph.
#
# Results:
# arc name of a arc guaranteed to not exist in the graph.
proc ::struct::graph::__generateUniqueArcName {name} {
variable ${name}::nextUnusedArc
while {[__arc_exists $name "arc${nextUnusedArc}"]} {
incr nextUnusedArc
}
return "arc${nextUnusedArc}"
}
# ::struct::graph::__generateUniqueNodeName --
#
# Generate a unique node name for the given graph.
#
# Arguments:
# name name of the graph.
#
# Results:
# node name of a node guaranteed to not exist in the graph.
proc ::struct::graph::__generateUniqueNodeName {name} {
variable ${name}::nextUnusedNode
while {[__node_exists $name "node${nextUnusedNode}"]} {
incr nextUnusedNode
}
return "node${nextUnusedNode}"
}
# ::struct::graph::_get --
#
# Get a keyed value from the graph itself
#
# Arguments:
# name name of the graph.
# key key to lookup
#
# Results:
# value value associated with the key given.
proc ::struct::graph::_get {name key} {
variable ${name}::graphAttr
if { ![info exists graphAttr($key)] } {
return -code error "invalid key \"$key\" for graph \"$name\""
}
return $graphAttr($key)
}
# ::struct::graph::_getall --
#
# Get an attribute dictionary from a graph.
#
# Arguments:
# name name of the graph.
# pattern optional, glob pattern
#
# Results:
# value value associated with the key given.
proc ::struct::graph::_getall {name {pattern *}} {
variable ${name}::graphAttr
return [array get graphAttr $pattern]
}
# ::struct::graph::_keys --
#
# Get a list of keys from a graph.
#
# Arguments:
# name name of the graph.
# pattern optional, glob pattern
#
# Results:
# value list of known keys
proc ::struct::graph::_keys {name {pattern *}} {
variable ${name}::graphAttr
return [array names graphAttr $pattern]
}
# ::struct::graph::_keyexists --
#
# Test for existence of a given key in a graph.
#
# Arguments:
# name name of the graph.
# key key to lookup
#
# Results:
# 1 if the key exists, 0 else.
proc ::struct::graph::_keyexists {name key} {
variable ${name}::graphAttr
return [info exists graphAttr($key)]
}
# ::struct::graph::_node --
#
# Dispatches the invocation of node methods to the proper handler
# procedure.
#
# Arguments:
# name name of the graph.
# cmd node command to invoke
# args arguments to propagate to the handler for the node command
#
# Results:
# As of the the invoked handler.
proc ::struct::graph::_node {name cmd args} {
# Split the args into command and args components
set sub __node_$cmd
if { [llength [info commands ::struct::graph::$sub]] == 0 } {
set optlist [lsort [info commands ::struct::graph::__node_*]]
set xlist {}
foreach p $optlist {
set p [namespace tail $p]
lappend xlist [string range $p 7 end]
}
set optlist [linsert [join $xlist ", "] "end-1" "or"]
return -code error \
"bad option \"$cmd\": must be $optlist"
}
uplevel 1 [linsert $args 0 ::struct::graph::$sub $name]
}
# ::struct::graph::__node_degree --
#
# Return the number of arcs adjacent to the specified node.
# If one of the restrictions -in or -out is given only
# incoming resp. outgoing arcs are counted.
#
# Arguments:
# name name of the graph.
# args option, followed by the node.
#
# Results:
# None.
proc ::struct::graph::__node_degree {name args} {
if {([llength $args] < 1) || ([llength $args] > 2)} {
return -code error "wrong # args: should be \"$name node degree ?-in|-out? node\""
}
switch -exact -- [llength $args] {
1 {
set opt {}
set node [lindex $args 0]
}
2 {
set opt [lindex $args 0]
set node [lindex $args 1]
}
default {return -code error "Can't happen, panic"}
}
# Validate the option.
switch -exact -- $opt {
{} -
-in -
-out {}
default {
return -code error "bad option \"$opt\": must be -in or -out"
}
}
# Validate the node
CheckMissingNode $name $node
variable ${name}::inArcs
variable ${name}::outArcs
switch -exact -- $opt {
-in {
set result [llength $inArcs($node)]
}
-out {
set result [llength $outArcs($node)]
}
{} {
set result [expr {[llength $inArcs($node)] \
+ [llength $outArcs($node)]}]
# loops count twice, don't do <set> arithmetics, i.e. no union!
if {0} {
array set coll {}
set result [llength $inArcs($node)]
foreach e $inArcs($node) {
set coll($e) .
}
foreach e $outArcs($node) {
if {[info exists coll($e)]} {continue}
incr result
set coll($e) .
}
}
}
default {return -code error "Can't happen, panic"}
}
return $result
}
# ::struct::graph::__node_delete --
#
# Remove a node from a graph, including all of its values.
# Additionally removes the arcs connected to this node.
#
# Arguments:
# name name of the graph.
# args list of the nodes to delete.
#
# Results:
# None.
proc ::struct::graph::__node_delete {name args} {
if {![llength $args]} {
return {wrong # args: should be "::struct::graph::__node_delete name node node..."}
}
# seen is used to catch duplicate nodes in the args
array set seen {}
foreach node $args {
if {[info exists seen($node)]} {
return -code error "node \"$node\" does not exist in graph \"$name\""
}
CheckMissingNode $name $node
set seen($node) .
}
variable ${name}::inArcs
variable ${name}::outArcs
variable ${name}::nodeAttr
foreach node $args {
# Remove all the arcs connected to this node
foreach e $inArcs($node) {
__arc_delete $name $e
}
foreach e $outArcs($node) {
# Check existence to avoid problems with
# loops (they are in and out arcs! at
# the same time and thus already deleted)
if { [__arc_exists $name $e] } {
__arc_delete $name $e
}
}
unset inArcs($node)
unset outArcs($node)
if {[info exists nodeAttr($node)]} {
unset ${name}::$nodeAttr($node)
unset nodeAttr($node)
}
}
return
}
# ::struct::graph::__node_exists --
#
# Test for existence of a given node in a graph.
#
# Arguments:
# name name of the graph.
# node node to look for.
#
# Results:
# 1 if the node exists, 0 else.
proc ::struct::graph::__node_exists {name node} {
return [info exists ${name}::inArcs($node)]
}
# ::struct::graph::__node_get --
#
# Get a keyed value from a node in a graph.
#
# Arguments:
# name name of the graph.
# node node to query.
# key key to lookup
#
# Results:
# value value associated with the key given.
proc ::struct::graph::__node_get {name node key} {
CheckMissingNode $name $node
variable ${name}::nodeAttr
if {![info exists nodeAttr($node)]} {
# No attribute data for this node, key has to be invalid.
return -code error "invalid key \"$key\" for node \"$node\""
}
upvar ${name}::$nodeAttr($node) data
if { ![info exists data($key)] } {
return -code error "invalid key \"$key\" for node \"$node\""
}
return $data($key)
}
# ::struct::graph::__node_getall --
#
# Get a serialized list of key/value pairs from a node in a graph.
#
# Arguments:
# name name of the graph.
# node node to query.
# pattern optional glob pattern to restrict retrieval
#
# Results:
# value value associated with the key given.
proc ::struct::graph::__node_getall {name node {pattern *}} {
CheckMissingNode $name $node
variable ${name}::nodeAttr
if {![info exists nodeAttr($node)]} {
# No attributes ...
return {}
}
upvar ${name}::$nodeAttr($node) data
return [array get data $pattern]
}
# ::struct::graph::__node_keys --
#
# Get a list of keys from a node in a graph.
#
# Arguments:
# name name of the graph.
# node node to query.
# pattern optional glob pattern to restrict retrieval
#
# Results:
# value value associated with the key given.
proc ::struct::graph::__node_keys {name node {pattern *}} {
CheckMissingNode $name $node
variable ${name}::nodeAttr
if {![info exists nodeAttr($node)]} {
# No attributes ...
return {}
}
upvar ${name}::$nodeAttr($node) data
return [array names data $pattern]
}
# ::struct::graph::__node_keyexists --
#
# Test for existence of a given key for a node in a graph.
#
# Arguments:
# name name of the graph.
# node node to query.
# key key to lookup
#
# Results:
# 1 if the key exists, 0 else.
proc ::struct::graph::__node_keyexists {name node key} {
CheckMissingNode $name $node
variable ${name}::nodeAttr
if {![info exists nodeAttr($node)]} {
# No attribute data for this node, key cannot exist.
return 0
}
upvar ${name}::$nodeAttr($node) data
return [info exists data($key)]
}
# ::struct::graph::__node_insert --
#
# Add a node to a graph.
#
# Arguments:
# name name of the graph.
# args node to insert; must be unique. If none is given,
# the routine will generate a unique node name.
#
# Results:
# node The name of the new node.
proc ::struct::graph::__node_insert {name args} {
if {[llength $args] == 0} {
# No node name was given; generate a unique one
set args [list [__generateUniqueNodeName $name]]
} else {
# seen is used to catch duplicate nodes in the args
array set seen {}
foreach node $args {
if {[info exists seen($node)]} {
return -code error "node \"$node\" already exists in graph \"$name\""
}
CheckDuplicateNode $name $node
set seen($node) .
}
}
variable ${name}::inArcs
variable ${name}::outArcs
foreach node $args {
# Set up the new node
set inArcs($node) {}
set outArcs($node) {}
}
return $args
}
# ::struct::graph::__node_opposite --
#
# Retrieve node opposite to the specified one, along the arc.
#
# Arguments:
# name name of the graph.
# node node to look up.
# arc arc to look up.
#
# Results:
# nodex Node opposite to <node,arc>
proc ::struct::graph::__node_opposite {name node arc} {
CheckMissingNode $name $node
CheckMissingArc $name $arc
variable ${name}::arcNodes
# Node must be connected to at least one end of the arc.
if {[string equal $node [lindex $arcNodes($arc) 0]]} {
set result [lindex $arcNodes($arc) 1]
} elseif {[string equal $node [lindex $arcNodes($arc) 1]]} {
set result [lindex $arcNodes($arc) 0]
} else {
return -code error "node \"$node\" and arc \"$arc\" are not connected\
in graph \"$name\""
}
return $result
}
# ::struct::graph::__node_set --
#
# Set or get a value for a node in a graph.
#
# Arguments:
# name name of the graph.
# node node to modify or query.
# key attribute to modify or query
# args ?value?
#
# Results:
# val value associated with the given key of the given node
proc ::struct::graph::__node_set {name node key args} {
if { [llength $args] > 1 } {
return -code error "wrong # args: should be \"$name node set node key ?value?\""
}
CheckMissingNode $name $node
if { [llength $args] > 0 } {
# Setting the value. This may have to create
# the attribute array for this particular
# node
variable ${name}::nodeAttr
if {![info exists nodeAttr($node)]} {
# No attribute data for this node,
# so create it as we need it now.
GenAttributeStorage $name node $node
}
upvar ${name}::$nodeAttr($node) data
return [set data($key) [lindex $args end]]
} else {
# Getting a value
return [__node_get $name $node $key]
}
}
# ::struct::graph::__node_append --
#
# Append a value for a node in a graph.
#
# Arguments:
# name name of the graph.
# node node to modify or query.
# args key value
#
# Results:
# val value associated with the given key of the given node
proc ::struct::graph::__node_append {name node key value} {
CheckMissingNode $name $node
variable ${name}::nodeAttr
if {![info exists nodeAttr($node)]} {
# No attribute data for this node,
# so create it as we need it.
GenAttributeStorage $name node $node
}
upvar ${name}::$nodeAttr($node) data
return [append data($key) $value]
}
# ::struct::graph::__node_attr --
#
# Return attribute data for one key and multiple nodes, possibly all.
#
# Arguments:
# name Name of the graph object.
# key Name of the attribute to retrieve.
#
# Results:
# children Dictionary mapping nodes to attribute data.
proc ::struct::graph::__node_attr {name key args} {
# Syntax:
#
# t attr key
# t attr key -nodes {nodelist}
# t attr key -glob nodepattern
# t attr key -regexp nodepattern
variable ${name}::nodeAttr
set usage "wrong # args: should be \"[list $name] node attr key ?-nodes list|-glob pattern|-regexp pattern?\""
if {([llength $args] != 0) && ([llength $args] != 2)} {
return -code error $usage
} elseif {[llength $args] == 0} {
# This automatically restricts the list
# to nodes which can have the attribute
# in question.
set nodes [array names nodeAttr]
} else {
# Determine a list of nodes to look at
# based on the chosen restriction.
foreach {mode value} $args break
switch -exact -- $mode {
-nodes {
# This is the only branch where we have to
# perform an explicit restriction to the
# nodes which have attributes.
set nodes {}
foreach n $value {
if {![info exists nodeAttr($n)]} continue
lappend nodes $n
}
}
-glob {
set nodes [array names nodeAttr $value]
}
-regexp {
set nodes {}
foreach n [array names nodeAttr] {
if {![regexp -- $value $n]} continue
lappend nodes $n
}
}
default {
return -code error "bad type \"$mode\": must be -glob, -nodes, or -regexp"
}
}
}
# Without possibly matching nodes
# the result has to be empty.
if {![llength $nodes]} {
return {}
}
# Now locate matching keys and their values.
set result {}
foreach n $nodes {
upvar ${name}::$nodeAttr($n) data
if {[info exists data($key)]} {
lappend result $n $data($key)
}
}
return $result
}
# ::struct::graph::__node_lappend --
#
# lappend a value for a node in a graph.
#
# Arguments:
# name name of the graph.
# node node to modify or query.
# args key value
#
# Results:
# val value associated with the given key of the given node
proc ::struct::graph::__node_lappend {name node key value} {
CheckMissingNode $name $node
variable ${name}::nodeAttr
if {![info exists nodeAttr($node)]} {
# No attribute data for this node,
# so create it as we need it.
GenAttributeStorage $name node $node
}
upvar ${name}::$nodeAttr($node) data
return [lappend data($key) $value]
}
# ::struct::graph::__node_unset --
#
# Remove a keyed value from a node.
#
# Arguments:
# name name of the graph.
# node node to modify.
# key attribute to remove
#
# Results:
# None.
proc ::struct::graph::__node_unset {name node key} {
CheckMissingNode $name $node
variable ${name}::nodeAttr
if {![info exists nodeAttr($node)]} {
# No attribute data for this node,
# nothing to do.
return
}
upvar ${name}::$nodeAttr($node) data
catch {unset data($key)}
if {[array size data] == 0} {
# No attributes stored for this node, squash the whole array.
unset nodeAttr($node)
unset data
}
return
}
# ::struct::graph::_nodes --
#
# Return a list of all nodes in a graph satisfying some restriction.
#
# Arguments:
# name name of the graph.
# args list of options and nodes specifying the restriction.
#
# Results:
# nodes list of nodes
proc ::struct::graph::_nodes {name args} {
CheckE $name nodes $args
switch -exact -- $cond {
none {set nodes [NodesNONE $name]}
in {set nodes [NodesIN $name $condNodes]}
out {set nodes [NodesOUT $name $condNodes]}
adj {set nodes [NodesADJ $name $condNodes]}
inner {set nodes [NodesINN $name $condNodes]}
embedding {set nodes [NodesEMB $name $condNodes]}
default {return -code error "Can't happen, panic"}
}
#
# We have a list of nodes that match the relation to the nodes.
# Now filter according to -key and -value.
#
if {$haveKey && $haveValue} {
set nodes [NodesKV $name $key $value $nodes]
} elseif {$haveKey} {
set nodes [NodesK $name $key $nodes]
}
#
# Apply the general filter command, if specified.
#
if {$haveFilter} {
lappend fcmd $name
set nodes [uplevel 1 [list ::struct::list filter $nodes $fcmd]]
}
return $nodes
}
proc ::struct::graph::NodesIN {name cn} {
# nodes -in.
# "Neighbours with arcs going into the node set"
#
# NODES/in (NS) := { source(a) | a in ARC/in (NS) }
# Result is all nodes with at least one arc going to
# at least one node in the list of arguments.
variable ${name}::inArcs
variable ${name}::arcNodes
set nodes {}
array set coll {}
foreach node $cn {
foreach e $inArcs($node) {
set n [lindex $arcNodes($e) 0]
if {[info exists coll($n)]} {continue}
lappend nodes $n
set coll($n) .
}
}
return $nodes
}
proc ::struct::graph::NodesOUT {name cn} {
# nodes -out.
# "Neighbours with arcs coming from the node set"
#
# NODES/out (NS) := { target(a) | a in ARC/out (NS) }
# Result is all nodes with at least one arc coming from
# at least one node in the list of arguments.
variable ${name}::outArcs
variable ${name}::arcNodes
set nodes {}
array set coll {}
foreach node $cn {
foreach e $outArcs($node) {
set n [lindex $arcNodes($e) 1]
if {[info exists coll($n)]} {continue}
lappend nodes $n
set coll($n) .
}
}
return $nodes
}
proc ::struct::graph::NodesADJ {name cn} {
# nodes -adj.
# "Neighbours of the node set"
#
# NODES/adj (NS) := NODES/in (NS) + NODES/out (NS)
# Result is all nodes with at least one arc coming from
# or going to at least one node in the list of arguments.
return [struct::set union \
[NodesIN $name $cn] \
[NodesOUT $name $cn]]
if 0 {
# Alternate implementation using arrays,
# implementing the set union directly,
# intertwined with the data retrieval.
foreach node $cn {
foreach e $inArcs($node) {
set n [lindex $arcNodes($e) 0]
if {[info exists coll($n)]} {continue}
lappend nodes $n
set coll($n) .
}
foreach e $outArcs($node) {
set n [lindex $arcNodes($e) 1]
if {[info exists coll($n)]} {continue}
lappend nodes $n
set coll($n) .
}
}
}
}
proc ::struct::graph::NodesINN {name cn} {
# nodes -adj.
# "Inner node of the node set"
#
# NODES/inner (NS) := NODES/adj (NS) * NS
# Result is all nodes from the set with at least one arc coming
# from or going to at least one node in the set.
#
# I.e the adjacent nodes also in the set.
return [struct::set intersect \
[NodesADJ $name $cn] $cn]
if 0 {
# Alternate implementation using arrays,
# implementing the set intersect/union
# directly, intertwined with the data retrieval.
array set group {}
foreach node $cn {
set group($node) .
}
foreach node $cn {
foreach e $inArcs($node) {
set n [lindex $arcNodes($e) 0]
if {![info exists group($n)]} {continue}
if { [info exists coll($n)]} {continue}
lappend nodes $n
set coll($n) .
}
foreach e $outArcs($node) {
set n [lindex $arcNodes($e) 1]
if {![info exists group($n)]} {continue}
if { [info exists coll($n)]} {continue}
lappend nodes $n
set coll($n) .
}
}
}
}
proc ::struct::graph::NodesEMB {name cn} {
# nodes -embedding.
# "Embedding nodes for the node set"
#
# NODES/emb (NS) := NODES/adj (NS) - NS
# Result is all nodes with at least one arc coming from or going
# to at least one node in the set, but not in the set itself
#
# I.e the adjacent nodes not in the set.
# Result is all nodes from the set with at least one arc coming
# from or going to at least one node in the set.
# I.e the adjacent nodes still in the set.
return [struct::set difference \
[NodesADJ $name $cn] $cn]
if 0 {
# Alternate implementation using arrays,
# implementing the set diff/union directly,
# intertwined with the data retrieval.
array set group {}
foreach node $cn {
set group($node) .
}
foreach node $cn {
foreach e $inArcs($node) {
set n [lindex $arcNodes($e) 0]
if {[info exists group($n)]} {continue}
if {[info exists coll($n)]} {continue}
lappend nodes $n
set coll($n) .
}
foreach e $outArcs($node) {
set n [lindex $arcNodes($e) 1]
if {[info exists group($n)]} {continue}
if {[info exists coll($n)]} {continue}
lappend nodes $n
set coll($n) .
}
}
}
}
proc ::struct::graph::NodesNONE {name} {
variable ${name}::inArcs
return [array names inArcs]
}
proc ::struct::graph::NodesKV {name key value nodes} {
set filteredNodes {}
foreach node $nodes {
catch {
set nval [__node_get $name $node $key]
if {$nval == $value} {
lappend filteredNodes $node
}
}
}
return $filteredNodes
}
proc ::struct::graph::NodesK {name key nodes} {
set filteredNodes {}
foreach node $nodes {
catch {
__node_get $name $node $key
lappend filteredNodes $node
}
}
return $filteredNodes
}
# ::struct::graph::__node_rename --
#
# Rename a node in place.
#
# Arguments:
# name name of the graph.
# node Name of the node to rename
# newname The new name of the node.
#
# Results:
# The new name of the node.
proc ::struct::graph::__node_rename {name node newname} {
CheckMissingNode $name $node
CheckDuplicateNode $name $newname
set oldname $node
# Perform the rename in the internal
# data structures.
# - graphAttr - not required, node independent.
# - arcAttr - not required, node independent.
# - counters - not required
variable ${name}::nodeAttr
variable ${name}::inArcs
variable ${name}::outArcs
variable ${name}::arcNodes
# Node relocation
set inArcs($newname) [set in $inArcs($oldname)]
unset inArcs($oldname)
set outArcs($newname) [set out $outArcs($oldname)]
unset outArcs($oldname)
if {[info exists nodeAttr($oldname)]} {
set nodeAttr($newname) $nodeAttr($oldname)
unset nodeAttr($oldname)
}
# Update all relevant arcs.
# 8.4: lset ...
foreach a $in {
set arcNodes($a) [list [lindex $arcNodes($a) 0] $newname]
}
foreach a $out {
set arcNodes($a) [list $newname [lindex $arcNodes($a) 1]]
}
return $newname
}
# ::struct::graph::_serialize --
#
# Serialize a graph object (partially) into a transportable value.
# If only a subset of nodes is serialized the result will be a sub-
# graph in the mathematical sense of the word: These nodes and all
# arcs which are only between these nodes. No arcs to modes outside
# of the listed set.
#
# Arguments:
# name Name of the graph.
# args list of nodes to place into the serialized graph
#
# Results:
# A list structure describing the part of the graph which was serialized.
proc ::struct::graph::_serialize {name args} {
# all - boolean flag - set if and only if the all nodes of the
# graph are chosen for serialization. Because if that is true we
# can skip the step finding the relevant arcs and simply take all
# arcs.
variable ${name}::arcNodes
variable ${name}::arcWeight
variable ${name}::inArcs
set all 0
if {[llength $args] > 0} {
set nodes [luniq $args]
foreach n $nodes {CheckMissingNode $name $n}
if {[llength $nodes] == [array size inArcs]} {
set all 1
}
} else {
set nodes [array names inArcs]
set all 1
}
if {$all} {
set arcs [array names arcNodes]
} else {
set arcs [eval [linsert $nodes 0 _arcs $name -inner]]
}
variable ${name}::nodeAttr
variable ${name}::arcAttr
variable ${name}::graphAttr
set na {}
set aa {}
array set np {}
# node indices, attribute data ...
set i 0
foreach n $nodes {
set np($n) [list $i]
incr i 3
if {[info exists nodeAttr($n)]} {
upvar ${name}::$nodeAttr($n) data
lappend np($n) [array get data]
} else {
lappend np($n) {}
}
}
# arc dictionary
set arcdata {}
foreach a $arcs {
foreach {src dst} $arcNodes($a) break
# Arc information
set arc [list $a]
lappend arc [lindex $np($dst) 0]
if {[info exists arcAttr($a)]} {
upvar ${name}::$arcAttr($a) data
lappend arc [array get data]
} else {
lappend arc {}
}
# Add weight information, if there is any.
if {[info exists arcWeight($a)]} {
lappend arc $arcWeight($a)
}
# Add the information to the node
# indices ...
lappend np($src) $arc
}
# Combine the transient data into one result.
set result [list]
foreach n $nodes {
lappend result $n
lappend result [lindex $np($n) 1]
lappend result [lrange $np($n) 2 end]
}
lappend result [array get graphAttr]
return $result
}
# ::struct::graph::_set --
#
# Set or get a keyed value from the graph itself
#
# Arguments:
# name name of the graph.
# key attribute to modify or query
# args ?value?
#
# Results:
# value value associated with the key given.
proc ::struct::graph::_set {name key args} {
if { [llength $args] > 1 } {
return -code error "wrong # args: should be \"$name set key ?value?\""
}
if { [llength $args] > 0 } {
variable ${name}::graphAttr
return [set graphAttr($key) [lindex $args end]]
} else {
# Getting a value
return [_get $name $key]
}
}
# ::struct::graph::_swap --
#
# Swap two nodes in a graph.
#
# Arguments:
# name name of the graph.
# node1 first node to swap.
# node2 second node to swap.
#
# Results:
# None.
proc ::struct::graph::_swap {name node1 node2} {
# Can only swap two real nodes
CheckMissingNode $name $node1
CheckMissingNode $name $node2
# Can't swap a node with itself
if { [string equal $node1 $node2] } {
return -code error "cannot swap node \"$node1\" with itself"
}
# Swapping nodes means swapping their labels, values and arcs
variable ${name}::outArcs
variable ${name}::inArcs
variable ${name}::arcNodes
variable ${name}::nodeAttr
# Redirect arcs to the new nodes.
foreach e $inArcs($node1) {lset arcNodes($e) end $node2}
foreach e $inArcs($node2) {lset arcNodes($e) end $node1}
foreach e $outArcs($node1) {lset arcNodes($e) 0 $node2}
foreach e $outArcs($node2) {lset arcNodes($e) 0 $node1}
# Swap arc lists
set tmp $inArcs($node1)
set inArcs($node1) $inArcs($node2)
set inArcs($node2) $tmp
set tmp $outArcs($node1)
set outArcs($node1) $outArcs($node2)
set outArcs($node2) $tmp
# Swap the values
# More complicated now with the possibility that nodes do not have
# attribute storage associated with them. But also
# simpler as we just have to swap/move the array
# reference
if {
[set ia [info exists nodeAttr($node1)]] ||
[set ib [info exists nodeAttr($node2)]]
} {
# At least one of the nodes has attribute data. We simply swap
# the references to the arrays containing them. No need to
# copy the actual data around.
if {$ia && $ib} {
set tmp $nodeAttr($node1)
set nodeAttr($node1) $nodeAttr($node2)
set nodeAttr($node2) $tmp
} elseif {$ia} {
set nodeAttr($node2) $nodeAttr($node1)
unset nodeAttr($node1)
} elseif {$ib} {
set nodeAttr($node1) $nodeAttr($node2)
unset nodeAttr($node2)
} else {
return -code error "Impossible condition."
}
} ; # else: No attribute storage => Nothing to do {}
return
}
# ::struct::graph::_unset --
#
# Remove a keyed value from the graph itself
#
# Arguments:
# name name of the graph.
# key attribute to remove
#
# Results:
# None.
proc ::struct::graph::_unset {name key} {
variable ${name}::graphAttr
if {[info exists graphAttr($key)]} {
unset graphAttr($key)
}
return
}
# ::struct::graph::_walk --
#
# Walk a graph using a pre-order depth or breadth first
# search. Pre-order DFS is the default. At each node that is visited,
# a command will be called with the name of the graph and the node.
#
# Arguments:
# name name of the graph.
# node node at which to start.
# args additional args: ?-order pre|post|both? ?-type {bfs|dfs}?
# -command cmd
#
# Results:
# None.
proc ::struct::graph::_walk {name node args} {
set usage "$name walk node ?-dir forward|backward?\
?-order pre|post|both? ?-type bfs|dfs? -command cmd"
if {[llength $args] < 2} {
return -code error "wrong # args: should be \"$usage\""
}
CheckMissingNode $name $node
# Set defaults
set type dfs
set order pre
set cmd ""
set dir forward
# Process specified options
for {set i 0} {$i < [llength $args]} {incr i} {
set flag [lindex $args $i]
switch -glob -- $flag {
"-type" {
incr i
if { $i >= [llength $args] } {
return -code error "value for \"$flag\" missing: should be \"$usage\""
}
set type [string tolower [lindex $args $i]]
}
"-order" {
incr i
if { $i >= [llength $args] } {
return -code error "value for \"$flag\" missing: should be \"$usage\""
}
set order [string tolower [lindex $args $i]]
}
"-command" {
incr i
if { $i >= [llength $args] } {
return -code error "value for \"$flag\" missing: should be \"$usage\""
}
set cmd [lindex $args $i]
}
"-dir" {
incr i
if { $i >= [llength $args] } {
return -code error "value for \"$flag\" missing: should be \"$usage\""
}
set dir [string tolower [lindex $args $i]]
}
default {
return -code error "unknown option \"$flag\": should be \"$usage\""
}
}
}
# Make sure we have a command to run, otherwise what's the point?
if { [string equal $cmd ""] } {
return -code error "no command specified: should be \"$usage\""
}
# Validate that the given type is good
switch -glob -- $type {
"dfs" {
set type "dfs"
}
"bfs" {
set type "bfs"
}
default {
return -code error "bad search type \"$type\": must be bfs or dfs"
}
}
# Validate that the given order is good
switch -glob -- $order {
"both" {
set order both
}
"pre" {
set order pre
}
"post" {
set order post
}
default {
return -code error "bad search order \"$order\": must be both,\
pre, or post"
}
}
# Validate that the given direction is good
switch -glob -- $dir {
"forward" {
set dir -out
}
"backward" {
set dir -in
}
default {
return -code error "bad search direction \"$dir\": must be\
backward or forward"
}
}
# Do the walk
set st [list ]
lappend st $node
array set visited {}
if { [string equal $type "dfs"] } {
if { [string equal $order "pre"] } {
# Pre-order Depth-first search
while { [llength $st] > 0 } {
set node [lindex $st end]
ldelete st end
# Skip all nodes already visited via some other path
# through the graph.
if {[info exists visited($node)]} continue
# Evaluate the command at this node
set cmdcpy $cmd
lappend cmdcpy enter $name $node
uplevel 1 $cmdcpy
set visited($node) .
# Add this node's neighbours (according to direction)
# Have to add them in reverse order
# so that they will be popped left-to-right
set next [_nodes $name $dir $node]
set len [llength $next]
for {set i [expr {$len - 1}]} {$i >= 0} {incr i -1} {
set nextnode [lindex $next $i]
if {[info exists visited($nextnode)]} {
# Skip nodes already visited
continue
}
lappend st $nextnode
}
}
} elseif { [string equal $order "post"] } {
# Post-order Depth-first search
while { [llength $st] > 0 } {
set node [lindex $st end]
if {[info exists visited($node)]} {
# Second time we are here, pop it,
# then evaluate the command.
ldelete st end
# Bug 2420330. Note: The visited node may be
# multiple times on the stack (neighbour of more
# than one node). Remove all occurences.
while {[set index [lsearch -exact $st $node]] != -1} {
set st [lreplace $st $index $index]
}
# Evaluate the command at this node
set cmdcpy $cmd
lappend cmdcpy leave $name $node
uplevel 1 $cmdcpy
} else {
# First visit. Remember it.
set visited($node) .
# Add this node's neighbours.
set next [_nodes $name $dir $node]
set len [llength $next]
for {set i [expr {$len - 1}]} {$i >= 0} {incr i -1} {
set nextnode [lindex $next $i]
if {[info exists visited($nextnode)]} {
# Skip nodes already visited
continue
}
lappend st $nextnode
}
}
}
} else {
# Both-order Depth-first search
while { [llength $st] > 0 } {
set node [lindex $st end]
if {[info exists visited($node)]} {
# Second time we are here, pop it,
# then evaluate the command.
ldelete st end
# Evaluate the command at this node
set cmdcpy $cmd
lappend cmdcpy leave $name $node
uplevel 1 $cmdcpy
} else {
# First visit. Remember it.
set visited($node) .
# Evaluate the command at this node
set cmdcpy $cmd
lappend cmdcpy enter $name $node
uplevel 1 $cmdcpy
# Add this node's neighbours.
set next [_nodes $name $dir $node]
set len [llength $next]
for {set i [expr {$len - 1}]} {$i >= 0} {incr i -1} {
set nextnode [lindex $next $i]
if {[info exists visited($nextnode)]} {
# Skip nodes already visited
continue
}
lappend st $nextnode
}
}
}
}
} else {
if { [string equal $order "pre"] } {
# Pre-order Breadth first search
while { [llength $st] > 0 } {
set node [lindex $st 0]
ldelete st 0
# Evaluate the command at this node
set cmdcpy $cmd
lappend cmdcpy enter $name $node
uplevel 1 $cmdcpy
set visited($node) .
# Add this node's neighbours.
foreach child [_nodes $name $dir $node] {
if {[info exists visited($child)]} {
# Skip nodes already visited
continue
}
lappend st $child
}
}
} else {
# Post-order Breadth first search
# Both-order Breadth first search
# Haven't found anything in Knuth
# and unable to define something
# consistent for myself. Leave it
# out.
return -code error "unable to do a ${order}-order breadth first walk"
}
}
return
}
# ::struct::graph::Union --
#
# Return a list which is the union of the elements
# in the specified lists.
#
# Arguments:
# args list of lists representing sets.
#
# Results:
# set list representing the union of the argument lists.
proc ::struct::graph::Union {args} {
switch -- [llength $args] {
0 {
return {}
}
1 {
return [lindex $args 0]
}
default {
foreach set $args {
foreach e $set {
set tmp($e) .
}
}
return [array names tmp]
}
}
}
# ::struct::graph::GenAttributeStorage --
#
# Create an array to store the attributes of a node in.
#
# Arguments:
# name Name of the graph containing the node
# type Type of object for the attribute
# obj Name of the node or arc which got attributes.
#
# Results:
# none
proc ::struct::graph::GenAttributeStorage {name type obj} {
variable ${name}::nextAttr
upvar ${name}::${type}Attr attribute
set attr "a[incr nextAttr]"
set attribute($obj) $attr
return
}
proc ::struct::graph::CheckMissingArc {name arc} {
if {![__arc_exists $name $arc]} {
return -code error "arc \"$arc\" does not exist in graph \"$name\""
}
}
proc ::struct::graph::CheckMissingNode {name node {prefix {}}} {
if {![__node_exists $name $node]} {
return -code error "${prefix}node \"$node\" does not exist in graph \"$name\""
}
}
proc ::struct::graph::CheckDuplicateArc {name arc} {
if {[__arc_exists $name $arc]} {
return -code error "arc \"$arc\" already exists in graph \"$name\""
}
}
proc ::struct::graph::CheckDuplicateNode {name node} {
if {[__node_exists $name $node]} {
return -code error "node \"$node\" already exists in graph \"$name\""
}
}
proc ::struct::graph::CheckE {name what arguments} {
# Discriminate between conditions and nodes
upvar 1 haveCond haveCond ; set haveCond 0
upvar 1 haveKey haveKey ; set haveKey 0
upvar 1 key key ; set key {}
upvar 1 haveValue haveValue ; set haveValue 0
upvar 1 value value ; set value {}
upvar 1 haveFilter haveFilter ; set haveFilter 0
upvar 1 fcmd fcmd ; set fcmd {}
upvar 1 cond cond ; set cond "none"
upvar 1 condNodes condNodes ; set condNodes {}
set wa_usage "wrong # args: should be \"$name $what ?-key key? ?-value value? ?-filter cmd? ?-in|-out|-adj|-inner|-embedding node node...?\""
set seenodes 0
for {set i 0} {$i < [llength $arguments]} {incr i} {
set arg [lindex $arguments $i]
switch -glob -- $arg {
-in -
-out -
-adj -
-inner -
-embedding {
if {$haveCond} {
return -code error "invalid restriction:\
illegal multiple use of\
\"-in\"|\"-out\"|\"-adj\"|\"-inner\"|\"-embedding\""
}
set haveCond 1
set cond [string range $arg 1 end]
set seenodes 1
}
-key {
if {($i + 1) == [llength $arguments]} {
return -code error $wa_usage
}
if {$haveKey} {
return -code error {invalid restriction: illegal multiple use of "-key"}
}
incr i
set key [lindex $arguments $i]
set haveKey 1
set seenodes 0
}
-value {
if {($i + 1) == [llength $arguments]} {
return -code error $wa_usage
}
if {$haveValue} {
return -code error {invalid restriction: illegal multiple use of "-value"}
}
incr i
set value [lindex $arguments $i]
set haveValue 1
set seenodes 0
}
-filter {
if {($i + 1) == [llength $arguments]} {
return -code error $wa_usage
}
if {$haveFilter} {
return -code error {invalid restriction: illegal multiple use of "-filter"}
}
incr i
set fcmd [lindex $arguments $i]
set haveFilter 1
set seenodes 0
}
-* {
if {$seenodes} {
lappend condNodes $arg
} else {
return -code error "bad restriction \"$arg\": must be -adj, -embedding,\
-filter, -in, -inner, -key, -out, or -value"
}
}
default {
lappend condNodes $arg
}
}
}
# Validate that there are nodes to use in the restriction.
# otherwise what's the point?
if {$haveCond} {
if {[llength $condNodes] == 0} {
return -code error $wa_usage
}
# Remove duplicates. Note: lsort -unique is not present in Tcl
# 8.2, thus not usable here.
array set nx {}
foreach c $condNodes {set nx($c) .}
set condNodes [array names nx]
unset nx
# Make sure that the specified nodes exist!
foreach node $condNodes {CheckMissingNode $name $node}
}
if {$haveValue && !$haveKey} {
return -code error {invalid restriction: use of "-value" without "-key"}
}
return
}
proc ::struct::graph::CheckSerialization {ser gavar navar aavar inavar outavar arcnvar arcwvar} {
upvar 1 \
$gavar graphAttr \
$navar nodeAttr \
$aavar arcAttr \
$inavar inArcs \
$outavar outArcs \
$arcnvar arcNodes \
$arcwvar arcWeight
array set nodeAttr {}
array set arcAttr {}
array set inArcs {}
array set outArcs {}
array set arcNodes {}
array set arcWeight {}
# Overall length ok ?
if {[llength $ser] % 3 != 1} {
return -code error \
"error in serialization: list length not 1 mod 3."
}
# Attribute length ok ? Dictionary!
set graphAttr [lindex $ser end]
if {[llength $graphAttr] % 2} {
return -code error \
"error in serialization: malformed graph attribute dictionary."
}
# Basic decoder pass
foreach {node attr narcs} [lrange $ser 0 end-1] {
if {![info exists inArcs($node)]} {
set inArcs($node) [list]
}
set outArcs($node) [list]
# Attribute length ok ? Dictionary!
if {[llength $attr] % 2} {
return -code error \
"error in serialization: malformed node attribute dictionary."
}
# Remember attribute data only for non-empty nodes
if {[llength $attr]} {
set nodeAttr($node) $attr
}
foreach arcd $narcs {
if {
([llength $arcd] != 3) &&
([llength $arcd] != 4)
} {
return -code error \
"error in serialization: arc information length not 3 or 4."
}
foreach {arc dst aattr} $arcd break
if {[info exists arcNodes($arc)]} {
return -code error \
"error in serialization: duplicate definition of arc \"$arc\"."
}
# Attribute length ok ? Dictionary!
if {[llength $aattr] % 2} {
return -code error \
"error in serialization: malformed arc attribute dictionary."
}
# Remember attribute data only for non-empty nodes
if {[llength $aattr]} {
set arcAttr($arc) $aattr
}
# Remember weight data if it was specified.
if {[llength $arcd] == 4} {
set arcWeight($arc) [lindex $arcd 3]
}
# Destination reference ok ?
if {
![string is integer -strict $dst] ||
($dst % 3) ||
($dst < 0) ||
($dst >= [llength $ser])
} {
return -code error \
"error in serialization: bad arc destination reference \"$dst\"."
}
# Get destination and reconstruct the
# various relationships.
set dstnode [lindex $ser $dst]
set arcNodes($arc) [list $node $dstnode]
lappend inArcs($dstnode) $arc
lappend outArcs($node) $arc
}
}
# Duplicate node names ?
if {[array size outArcs] < ([llength $ser] / 3)} {
return -code error \
"error in serialization: duplicate node names."
}
# Ok. The data is now ready for the caller.
return
}
##########################
# Private functions follow
#
# Do a compatibility version of [lset] for pre-8.4 versions of Tcl.
# This version does not do multi-arg [lset]!
proc ::struct::graph::K { x y } { set x }
if { [package vcompare [package provide Tcl] 8.4] < 0 } {
proc ::struct::graph::lset { var index arg } {
upvar 1 $var list
set list [::lreplace [K $list [set list {}]] $index $index $arg]
}
}
proc ::struct::graph::ldelete {var index {end {}}} {
upvar 1 $var list
if {$end == {}} {set end $index}
set list [lreplace [K $list [set list {}]] $index $end]
return
}
proc ::struct::graph::luniq {list} {
array set _ {}
set result [list]
foreach e $list {
if {[info exists _($e)]} {continue}
lappend result $e
set _($e) .
}
return $result
}
# ### ### ### ######### ######### #########
## Ready
namespace eval ::struct {
# Put 'graph::graph' into the general structure namespace
# for pickup by the main management.
namespace import -force graph::graph_tcl
}