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Class: Bundler::PubGrub::PartialSolution

Relationships & Source Files
Inherits: Object
Defined in: lib/bundler/vendor/pub_grub/lib/pub_grub/partial_solution.rb

Class Method Summary

Instance Attribute Summary

Instance Method Summary

Constructor Details

.new ⇒ PartialSolution

[ GitHub ] 

  


# File 'lib/bundler/vendor/pub_grub/lib/pub_grub/partial_solution.rb', line 8



def initialize
  reset!

  @attempted_solutions = 1
  @backtracking = false
end


  







Instance Attribute Details



  

    #assignments   (readonly)
  

  [ GitHub ]


  

  


# File 'lib/bundler/vendor/pub_grub/lib/pub_grub/partial_solution.rb', line 5



attr_reader :assignments, :decisions


  








  

    #attempted_solutions   (readonly)
  

  [ GitHub ]


  

  


# File 'lib/bundler/vendor/pub_grub/lib/pub_grub/partial_solution.rb', line 6



attr_reader :attempted_solutions


  








  

    #decisions   (readonly)
  

  [ GitHub ]


  

  


# File 'lib/bundler/vendor/pub_grub/lib/pub_grub/partial_solution.rb', line 5



attr_reader :assignments, :decisions


  







Instance Method Details



  

    #add_assignment(assignment)   (private)
  

  [ GitHub ]


  

  


# File 'lib/bundler/vendor/pub_grub/lib/pub_grub/partial_solution.rb', line 101



def add_assignment(assignment)
  term = assignment.term
  package = term.package

  @assignments << assignment
  @assignments_by[package] << assignment

  @required[package] = true if term.positive?

  if @terms.key?(package)
    old_term = @terms[package]
    @terms[package] = old_term.intersect(term)
  else
    @terms[package] = term
  end
  @relation_cache[package].clear

  @cumulative_assignments[assignment] = @terms[package]
end


  








  

    #backtrack(previous_level)  
  

  [ GitHub ]


  

  


# File 'lib/bundler/vendor/pub_grub/lib/pub_grub/partial_solution.rb', line 62



def backtrack(previous_level)
  @backtracking = true

  new_assignments = assignments.select do |assignment|
    assignment.decision_level <= previous_level
  end

  new_decisions = Hash[decisions.first(previous_level)]

  reset!

  @decisions = new_decisions

  new_assignments.each do |assignment|
    add_assignment(assignment)
  end
end


  








  

    #decide(package, version)  
  

  [ GitHub ]


  

  


# File 'lib/bundler/vendor/pub_grub/lib/pub_grub/partial_solution.rb', line 53



def decide(package, version)
  @attempted_solutions += 1 if @backtracking
  @backtracking = false;

  decisions[package] = version
  assignment = Assignment.decision(package, version, decision_level, assignments.length)
  add_assignment(assignment)
end


  








  

    #decision_level  
  

  [ GitHub ]


  

  


# File 'lib/bundler/vendor/pub_grub/lib/pub_grub/partial_solution.rb', line 15



def decision_level
  @decisions.length
end


  








  

    #derive(term, cause)  
  

  [ GitHub ]


  

  


# File 'lib/bundler/vendor/pub_grub/lib/pub_grub/partial_solution.rb', line 31



def derive(term, cause)
  add_assignment(Assignment.new(term, cause, decision_level, assignments.length))
end


  








  

    #relation(term)  
  

  [ GitHub ]


  

  


# File 'lib/bundler/vendor/pub_grub/lib/pub_grub/partial_solution.rb', line 19



def relation(term)
  package = term.package
  return :overlap if !@terms.key?(package)

  @relation_cache[package][term] ||=
    @terms[package].relation(term)
end


  








  

    #reset!   (private)
  

  [ GitHub ]


  

  


# File 'lib/bundler/vendor/pub_grub/lib/pub_grub/partial_solution.rb', line 82



def reset!
  # { Array<Assignment> }
  @assignments = []

  # { Package => Array<Assignment> }
  @assignments_by = Hash.new { |h,k| h[k] = [] }
  @cumulative_assignments = {}.compare_by_identity

  # { Package => Package::Version }
  @decisions = {}

  # { Package => Term }
  @terms = {}
  @relation_cache = Hash.new { |h,k| h[k] = {} }

  # { Package => Boolean }
  @required = {}
end


  








  

    #satisfier(term)  
  

  [ GitHub ]


  

  


# File 'lib/bundler/vendor/pub_grub/lib/pub_grub/partial_solution.rb', line 35



def satisfier(term)
  assignment =
    @assignments_by[term.package].bsearch do |assignment_by|
      @cumulative_assignments[assignment_by].satisfies?(term)
    end

  assignment || raise("#{term} unsatisfied")
end


  








  

    #satisfies?(term)  ⇒ Boolean 
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/bundler/vendor/pub_grub/lib/pub_grub/partial_solution.rb', line 27



def satisfies?(term)
  relation(term) == :subset
end


  








  

    #unsatisfied  
  



  

    

A list of unsatisfied terms


  



  [ GitHub ]


  

  


# File 'lib/bundler/vendor/pub_grub/lib/pub_grub/partial_solution.rb', line 45



def unsatisfied
  @required.keys.reject do |package|
    @decisions.key?(package)
  end.map do |package|
    @terms[package]
  end
end