Class: PetriNet::Arc

Inherits:
Base
  • Object
show all
Defined in:
lib/petri_net/arc.rb

Overview

Arc

Instance Attribute Summary collapse

Attributes inherited from Base

#logger

Instance Method Summary collapse

Methods inherited from Base

#next_object_id, #reset

Constructor Details

#initialize(options = {}) {|_self| ... } ⇒ Arc

Creates an arc. An arc is an directed edge between a place and a transition (or visa versa) and can have a weight which indicates how many token it comsumes or produces from/to the place

Yields:

  • (_self)

Yield Parameters:

  • _self (PetriNet::Arc) —

    the object that the method was called on



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# File 'lib/petri_net/arc.rb', line 21

def initialize(options = {}, &block)
    @id = next_object_id
    @name = (options[:name] or "Arc#{@id}")
    @description = (options[:description] or "Arc #{@id}")
    @weight = (options[:weight] or 1)
    self.add_source(options[:source]) unless options[:source].nil?
    self.add_destination(options[:destination]) unless options[:destination].nil?

    yield self unless block == nil
end

Instance Attribute Details

#description ⇒ Object

Description



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# File 'lib/petri_net/arc.rb', line 9

def description
  @description
end

#destination ⇒ Object (readonly)

Source-object



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# File 'lib/petri_net/arc.rb', line 15

def destination
  @destination
end

#id ⇒ Object (readonly)

Unique ID



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# File 'lib/petri_net/arc.rb', line 5

def id
  @id
end

#name ⇒ Object

human readable name



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# File 'lib/petri_net/arc.rb', line 7

def name
  @name
end

#net=(value) ⇒ Object (writeonly)

The net this arc belongs to



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# File 'lib/petri_net/arc.rb', line 17

def net=(value)
  @net = value
end

#source ⇒ Object (readonly)

Source-object



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# File 'lib/petri_net/arc.rb', line 13

def source
  @source
end

#weight ⇒ Object

Arc weight



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# File 'lib/petri_net/arc.rb', line 11

def weight
  @weight
end

Instance Method Details

#<=>(object) ⇒ Object 



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# File 'lib/petri_net/arc.rb', line 120

def <=>(object)
    return false unless object.class.to_s == "PetriNet::Arc"
    return false unless object.source == self.source && object.destination == self.destination
    return object.weight <=> self.weight
end

#add_destination(object) ⇒ Object

Add a destination object



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# File 'lib/petri_net/arc.rb', line 47

def add_destination(object)
    if object.class.to_s == "String"
        object = (@net.get_place object or @net.get_transition object)
    end
    if validate_source_destination(object)
        @destination = object
        object.add_input(self)
    else
        raise "Invalid arc destination object: #{object.class}"
    end
end

#add_source(object) ⇒ Object

Add a source object to this arc. Validation of the source object will be performed before the object is added to the arc and an exception will be raised.



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# File 'lib/petri_net/arc.rb', line 34

def add_source(object)
    if object.class.to_s == "String"
        object = (@net.get_place object or @net.get_transition object)
    end
    if validate_source_destination(object)
        @source = object
        object.add_output(self)
    else
        raise "Invalid arc source object: #{object.class}"
    end
end

#need_update?(net) ⇒ Boolean

Checks if the information in this arc are still correct. The information can get wrong if you merge two nets together.

Returns:

  • (Boolean) 


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# File 'lib/petri_net/arc.rb', line 103

def need_update? net
    if net.get_object(@source.id).nil? || (@source.name != net.get_object(@source.id).name)
        return true
    end
    if  net.get_object(@destination.id).nil? || (@destination.name != net.get_object(@destination.id).name)
        return true
    end
end

#ordinary? ⇒ Boolean

A Petri Net is said to be ordinary if all of its arc weights are 1’s. Is this arc ordinary?

Returns:

  • (Boolean) 


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# File 'lib/petri_net/arc.rb', line 61

def ordinary?
    @weight == 1
end

#to_gv ⇒ Object

Gives the GraphViz-representation of this arc as string of a GV-Edge



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# File 'lib/petri_net/arc.rb', line 97

def to_gv
    "\t#{@source.gv_id} -> #{@destination.gv_id} [ label = \"#{@name}\", headlabel = \"#{@weight}\" ];\n"
end

#to_s ⇒ Object

Stringify this arc.



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# File 'lib/petri_net/arc.rb', line 92

def to_s
    "#{@id}: #{@name} (#{@weight}) #{@source.id} -> #{@destination.id}"
end

#update(net) ⇒ Object

Updates the information in this arc Should only be necessary if PetriNet::Arc#need_update? is true affects source and destination



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# File 'lib/petri_net/arc.rb', line 115

def update net
    @source.id = net.objects_find_index @source
    @destination.id = net.objects_find_index @destination
end

#validate(net) ⇒ Object

Validate this arc.



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# File 'lib/petri_net/arc.rb', line 66

def validate(net)
    return false if @id < 1
    return false if @name.nil? or @name.length <= 0
    return false if @weight < 1
    return false if @source.nil? or @destination.nil?
    return false if @source == @destination
    return false if @source.class == @destination.class

    if @source.class.to_s == "PetriNet::Place"
        return net.objects_include? @source 
    elsif @source.class.to_s == "PetriNet::Transition"
        return net.objects_include? @source
    else
        return false
    end
    if @destination.class.to_s == "PetriNet::Place"
        return net.objects.include? @destination
    elsif @destination.class.to_s == "PetriNet::Transition"
        return net.objects.include? @destination
    else
        return false
    end
    return true
end