Class: StableMatch::Runner

Inherits:
Object
  • Object
show all
Includes:
Util::InitializeWithDefaults
Defined in:
lib/stable_match/runner.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Util::InitializeWithDefaults

included

Constructor Details

#initialize(set1, set2, strategy = :symmetric) ⇒ Runner

Returns a new instance of Runner.



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# File 'lib/stable_match/runner.rb', line 42

def initialize( set1 , set2 , strategy = :symmetric )
  @set1     = set1
  @set2     = set2
  @strategy = strategy
end

Instance Attribute Details

#built ⇒ Object Also known as: built?

Whether the sets have been built into candidate sets



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# File 'lib/stable_match/runner.rb', line 9

def built
  @built
end

#candidate_set1 ⇒ Object

The first set to use in the matching



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# File 'lib/stable_match/runner.rb', line 20

def candidate_set1
  @candidate_set1
end

#candidate_set2 ⇒ Object

The second set to use in the matching



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# File 'lib/stable_match/runner.rb', line 25

def candidate_set2
  @candidate_set2
end

#candidates ⇒ Object

Container for all the candidates



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# File 'lib/stable_match/runner.rb', line 13

def candidates
  @candidates
end

#checked ⇒ Object Also known as: checked?

Whether the sets have been checked for consistency



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# File 'lib/stable_match/runner.rb', line 16

def checked
  @checked
end

#set1 ⇒ Object

The first set to use in the matching



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# File 'lib/stable_match/runner.rb', line 20

def set1
  @set1
end

#set2 ⇒ Object

The second set to use in the matching



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# File 'lib/stable_match/runner.rb', line 25

def set2
  @set2
end

#strategy ⇒ Object

The way in which the run loop executes

Should be either: symmetric OR asymmetric



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# File 'lib/stable_match/runner.rb', line 32

def strategy
  @strategy
end

Class Method Details

.run(*args) ⇒ Object

Class-level factory method to construct, check, build and run a Runner instance



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# File 'lib/stable_match/runner.rb', line 35

def self.run( *args )
  runner = new *args
  runner.check!
  runner.build!
  runner.run
end

Instance Method Details

#build! ⇒ Object

Convert set1 and set2 into candidate_set1 and candidate_set2 Also, track a master array of candidates Mark itself as built



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# File 'lib/stable_match/runner.rb', line 59

def build!
  set1.each do | target , options |
    candidate =
      Candidate.new \
        target,
        *( options.first.is_a?( Array ) ? options : [ options ] )

    candidates.push candidate
    candidate_set1[ target ] = candidate
  end

  set2.each do | target , options |
    candidate =
      Candidate.new \
        target,
        *( options.first.is_a?( Array ) ? options : [ options ] )

    candidates.push candidate
    candidate_set2[ target ] = candidate
  end

  candidate_set1.each do | target , candidate |
    candidate.preferences =
      candidate.raw_preferences.map { | preference_target | candidate_set2[ preference_target ] }
  end

  candidate_set2.each do | target , candidate |
    candidate.preferences =
      candidate.raw_preferences.map { | preference_target | candidate_set1[ preference_target ] }
  end

  # We've built the candidates
  self.built = true
end

#check! ⇒ Object

Run basic checks against each raw set Meant to be run before being built into candidate sets Mark itself as checked



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# File 'lib/stable_match/runner.rb', line 97

def check!
  error     = proc { | message | raise ArgumentError.new( message ) }
  set1_keys = set1.keys
  set2_keys = set2.keys
  set1_size = set1.size
  set2_size = set2.size

  # Check set1
  set1.each do | target , options |
    message = "Preferences for #{ target.inspect } in `set1` do not match availabilities in `set2`!"
    options = options.first if options.first.is_a?( Array )
    error[ message ] unless \
      # Anything there is a preference for is in the other set
      ( options.all? { | preference | set2_keys.include?( preference ) } )
  end

  # Check set2 the same way
  set2.each do | target , options |
    message = "Preferences for #{ target.inspect } in `set2` do not match availabilities in `set1`!"
    options = options.first if options.first.is_a?( Array )
    error[ message ] unless \
      # Anything there is a preference for is in the other set
      ( options.all? { | preference | set1_keys.include?( preference ) } )
  end

  # We've run the check
  self.checked = true
end

#initialize_defaults! ⇒ Object 



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# File 'lib/stable_match/runner.rb', line 48

def initialize_defaults!
  @built          ||= false
  @candidates     ||= []
  @checked        ||= false
  @candidate_set1 ||= {}
  @candidate_set2 ||= {}
end

#inspect ⇒ Object Also known as: pretty_inspect 



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# File 'lib/stable_match/runner.rb', line 126

def inspect
  candidates.map( &:inspect ).join "\n\n"
end

#remaining_candidates ⇒ Object

This method respects the runner’s strategy!

List the remaining candidates that: -> have remaining slots available for matches AND -> have not already proposed to all of their preferences



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# File 'lib/stable_match/runner.rb', line 139

def remaining_candidates
  case strategy.to_sym
  when :symmetric
    candidates.reject { | candidate | candidate.full? || candidate.exhausted_preferences? }
  when :asymmetric
    candidate_set1.values.reject { | candidate | candidate.full? || candidate.exhausted_preferences? }
  end
end

#run ⇒ Object

While there are remaining candidates, ask each one to propose to all of their preferences until: -> a candidate has proposed to all of their preferences -> a candidate has no more matching_positions to be filled



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# File 'lib/stable_match/runner.rb', line 151

def run
  while ( rcs = remaining_candidates ).any?
    rcs.each do | candidate |
      while !candidate.exhausted_preferences? && candidate.free?
        candidate.propose_to_next_preference
      end
    end
  end
  self
end