Class: RDF::Normalize::Carroll2001

Inherits:
Base
  • Object
show all
Includes:
Enumerable
Defined in:
lib/rdf/normalize/carroll2001.rb

Instance Attribute Summary

Attributes inherited from Base

#dataset

Instance Method Summary collapse

Methods included from Enumerable

#canonicalize

Methods inherited from Base

#to_hash

Constructor Details

#initialize(enumerable, **options) ⇒ RDF::Enumerable

Create an enumerable with grounded nodes

Parameters:



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# File 'lib/rdf/normalize/carroll2001.rb', line 10

def initialize(enumerable, **options)
  @dataset = enumerable
end

Instance Method Details

#each(&block) ⇒ Object 



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# File 'lib/rdf/normalize/carroll2001.rb', line 14

def each(&block)
  ground_statements, anon_statements = [], []
  dataset.each_statement do |statement|
    (statement.has_blank_nodes? ? anon_statements : ground_statements) << statement
  end

  nodes = anon_statements.map(&:to_quad).flatten.compact.select(&:node?).uniq

  # Create a hash signature of every node, based on the signature of
  # statements it exists in.  
  # We also save hashes of nodes that cannot be reliably known; we will use
  # that information to eliminate possible recursion combinations.
  # 
  # Any mappings given in the method parameters are considered grounded.
  hashes, ungrounded_hashes = hash_nodes(anon_statements, nodes, {})

  # FIXME: likely need to iterate until hashes and ungrounded_hashes are the same size
  while hashes.size != ungrounded_hashes.size
    raise "Not done"
  end

  # Enumerate all statements, replacing nodes with new ground nodes using the hash as an identifier
  ground_statements.each(&block)
  anon_statements.each do |statement|
    quad = statement.to_quad.compact.map do |term|
      term.node? ? RDF::Node.intern(hashes[term]) : term
    end
    block.call RDF::Statement.from(quad)
  end
end