Class: Wongi::Engine::Network

Inherits:
Object
  • Object
show all
Includes:
Wongi::Engine::NetworkParts::Collectable
Defined in:
lib/wongi-engine/network.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Wongi::Engine::NetworkParts::Collectable

#add_collector, #add_error_collector, #collected_tokens, #collection, #collectors, #error_collectors, #errors

Constructor Details

#initialize ⇒ Network

Returns a new instance of Network.



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# File 'lib/wongi-engine/network.rb', line 47

def initialize
  @timeline = []
  self.alpha_top = AlphaMemory.new( Template.new( :_, :_, :_ ), self )
  self.alpha_hash = { alpha_top.template.hash => alpha_top }
  self.beta_top = BetaMemory.new(nil)
  self.beta_top.rete = self
  self.beta_top.seed
  self.queries = {}
  self.results = {}
  @cache = {}
  @revns = {}

  @productions = { }

  @collectors = {}
  @collectors[:error] = []

end

Instance Attribute Details

#alpha_top ⇒ Object

Returns the value of attribute alpha_top.



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# File 'lib/wongi-engine/network.rb', line 7

def alpha_top
  @alpha_top
end

#beta_top ⇒ Object

Returns the value of attribute beta_top.



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# File 'lib/wongi-engine/network.rb', line 7

def beta_top
  @beta_top
end

#overlays ⇒ Object (readonly) 



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# File 'lib/wongi-engine/network.rb', line 104

def overlays
  @overlays
end

#productions ⇒ Object (readonly)

Returns the value of attribute productions.



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# File 'lib/wongi-engine/network.rb', line 9

def productions
  @productions
end

#queries ⇒ Object

Returns the value of attribute queries.



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# File 'lib/wongi-engine/network.rb', line 8

def queries
  @queries
end

#results ⇒ Object

Returns the value of attribute results.



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# File 'lib/wongi-engine/network.rb', line 8

def results
  @results
end

Instance Method Details

#<<(something) ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 198

def << something
  if something.respond_to?( :install )
    something.install( self )
  else
    case something
    when Array
      assert WME.new( *something )
    when WME
      assert something
    # when Wongi::RDF::Statement
    #   assert WME.new( something.subject, something.predicate, something.object, self )
    #when Wongi::RDF::Document
      #  something.statements.each do |st|
      #    assert WME.new( st.subject, st.predicate, st.object, self )
      #  end
    when Network
      something.wmes.each { |wme| assert( wme ) }
    else
      raise Error, "I don't know how to accept a #{something.class}"
    end
  end
end

#add_overlay(o) ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 94

def add_overlay(o)
  overlays << o
end

#alphas ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 74

def alphas
  alpha_hash.values
end

#assert(wme) ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 108

def assert(wme)
  default_overlay.assert(wme)
end

#cache(s, p, o) ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 267

def cache s, p, o
  compile_alpha Template.new(s, p, o)
end

#compile_alpha(condition) ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 235

def compile_alpha condition
  template = Template.new :_, :_, :_
  time = condition.time

  template.subject = condition.subject unless Template.variable?( condition.subject )
  template.predicate = condition.predicate unless Template.variable?( condition.predicate )
  template.object = condition.object unless Template.variable?( condition.object )

  hash = template.hash
  # puts "COMPILED CONDITION #{condition} WITH KEY #{key}"
  if time == 0
    return self.alpha_hash[ hash ] if self.alpha_hash.has_key?( hash )
  else
    return @timeline[time+1][ hash ] if @timeline[time+1] && @timeline[time+1].has_key?( hash )
  end

  alpha = AlphaMemory.new( template, self )

  if time == 0
    self.alpha_hash[ hash ] = alpha
    initial_fill alpha
  else
    if @timeline[time+1].nil?
      # => ensure lineage from 0 to time
      compile_alpha condition.class.new(condition.subject, condition.predicate, condition.object, time: time + 1)
      @timeline.unshift Hash.new
    end
    @timeline[time+1][ hash ] = alpha
  end
  alpha
end

#debug! ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 21

def debug!
  extend NetworkParts::Debug
end

#default_overlay ⇒ Object

def import thing

case thing
when String, Numeric, TrueClass, FalseClass, NilClass, Wongi::RDF::Node
  thing
when Symbol
  thing
else
  thing
end

end



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# File 'lib/wongi-engine/network.rb', line 89

def default_overlay
  @default_overlay ||= DataOverlay.new(self)
end

#dump ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 66

def dump
  beta_top.dump
end

#each(*args) ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 303

def each *args
  return unless block_given?
  unless args.length == 0 || args.length == 3
    raise Error, "Network#each expects a pattern or nothing at all"
  end
  s, p, o = if args.empty?
    [:_, :_, :_]
  else
    args
  end
  no_check = s == :_ && p == :_ && o == :_
  template = Template.new(s, p, o).import_into self
  alpha_top.wmes.each do |wme|
    yield wme if (no_check || wme =~ template)
  end
end

#execute(name, valuations) ⇒ Object

Raises:



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# File 'lib/wongi-engine/network.rb', line 289

def execute name, valuations
  beta = self.queries[name]
  raise Error, "Undefined query #{name}; known queries are #{queries.keys}" unless beta
  beta.subst valuations
end

#exists?(wme) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/wongi-engine/network.rb', line 299

def exists? wme
  @cache[ wme ]
end

#find(s, p, o) ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 329

def find s, p, o
  template = Template.new(s, p, o)
  source = best_alpha(template)
  # puts "looking for #{template} among #{source.wmes.size} triples of #{source.template}"
  source.wmes.detect { |wme| wme =~ template }
end

#in_snapshot? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/wongi-engine/network.rb', line 163

def in_snapshot?
  @in_snapshot
end

#initial_fill(alpha) ⇒ Object

TODO: pick an alpha with fewer candidates to go through



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# File 'lib/wongi-engine/network.rb', line 272

def initial_fill alpha
  alpha_top.wmes.each do |wme|
    alpha.activate wme if wme =~ alpha.template
  end
end

#inspect ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 295

def inspect
  "<Rete>"
end

#install_query(query) ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 230

def install_query( query )
  derived = query.import_into self
  prepare_query derived.name, derived.conditions, derived.parameters, derived.actions
end

#install_rule(rule) ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 221

def install_rule( rule )
  derived = rule.import_into self
  production = build_production beta_top, derived.conditions, [], derived.actions, false
  if rule.name
    productions[ rule.name ] = production
  end
  production
end

#prepare_query(name, conditions, parameters, actions = []) ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 282

def prepare_query name, conditions, parameters, actions = []
  query = self.queries[ name ] = BetaMemory.new( nil )
  query.rete = self
  query.seed(Hash[parameters.map{ |param| [param, nil]}])
  self.results[ name ] = build_production query, conditions, parameters, actions, true
end

#query(name, &block) ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 192

def query name, &block
  q = DSL::Query.new name
  q.instance_eval &block
  self << q
end

#rdf! ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 25

def rdf!
  if ! defined? Wongi::RDF::DocumentSupport
    begin
      require 'wongi-rdf'
    rescue LoadError => e
      raise "'wongi-rdf' is required for RDF support"
    end
  end

  extend Wongi::RDF::DocumentSupport
  class << self
    def statements
      alpha_top.wmes
    end
  end

  @namespaces = { }
  @blank_counter = 1
  @ns_counter = 0
  @used_blanks = { }
end

#real_assert(wme) ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 117

def real_assert( wme )
  unless wme.rete == self
    wme = wme.import_into self
  end

  if existing = @cache[wme]
    existing.manual! if wme.manual?
    return
  end

  # puts "ASSERTING #{wme}"
  @cache[wme] = wme

  alphas_for( wme ).each { |a| a.activate wme }

  wme
end

#real_retract(wme, options) ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 136

def real_retract wme, options
  real = @cache[wme]

  return if real.nil?
  if real.generated? # still some generator tokens left
    if real.manual?
      real.manual = false
    else
      raise Error, "cannot retract automatic facts"
    end
  else
    if options[:automatic] && real.manual? # auto-retracting a fact that has been added manually
      return
    end
  end

  @cache.delete(real)

  alphas_for( real ).each { |a| a.deactivate real }
end

#remove_overlay(o) ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 99

def remove_overlay(o)
  overlays.delete(o) unless o == default_overlay
end

#remove_production(pnode) ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 278

def remove_production pnode
  delete_node_with_ancestors pnode
end

#retract(wme, options = {}) ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 112

def retract(wme, options = {})
  default_overlay.retract(wme, options)
end

#rule(name = nil, &block) ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 186

def rule name = nil, &block
  r = DSL::Rule.new( name || generate_rule_name )
  r.instance_eval &block
  self << r
end

#select(s, p, o) ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 320

def select s, p, o
  template = Template.new(s, p, o)
  matching = alpha_top.wmes.select { |wme| wme =~ template }
  if block_given?
    matching.each { |st| yield st.subject, st.predicate, st.object }
  end
  matching
end

#snapshot! ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 167

def snapshot!
  @timeline.each_with_index do |slice, index|
    source = if index == @timeline.size - 1
      alpha_hash
    else
      @timeline[index+1]
    end
    # puts "source = #{source}"
    wmes = {}
    slice.each { |key, alpha| wmes[key] = alpha.wmes }
    slice.each do |key, alpha|
      in_snapshot {
        wmes[key].dup.each { |wme| wme.destroy }
      }
      alpha.snapshot! source[key]
    end
  end
end

#with_overlay(&block) ⇒ Object 



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# File 'lib/wongi-engine/network.rb', line 70

def with_overlay(&block)
  default_overlay.with_child(&block)
end

#wmes ⇒ Object Also known as: statements, facts 



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# File 'lib/wongi-engine/network.rb', line 157

def wmes
  alpha_top.wmes
end