Module: Predicate::In

Includes:
Expr
Defined in:
lib/predicate/nodes/in.rb

Constant Summary

Constants included from Expr

Expr::OP_NEGATIONS

Instance Method Summary collapse

Methods included from Expr

#!, #and_split, #attr_split, #contradiction?, #identifier?, #literal?, #opaque?, #qualify, #rename, #sexpr, #tautology?, #to_s, #to_sequel, #|

Methods included from Factory

#and, #between, #comp, #contradiction, #from_hash, #in, #intersect, #literal, #match, #native, #not, #opaque, #or, #qualified_identifier, #tautology

Instance Method Details

#&(other) ⇒ Object 



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# File 'lib/predicate/nodes/in.rb', line 18

def &(other)
  # we only optimize with another In
  return super unless other.is_a?(In)

  # we only optimize is same free variables
  fv = free_variables
  return super unless fv.size == 1 && fv == other.free_variables

  # we only optimize if both right terms are literals
  return super unless right.literal? and other.right.literal?

  intersection = right.value & other.right.value
  if intersection.empty?
    Factory.contradiction
  elsif intersection.size == 1
    Factory.eq(fv.first, [:literal, intersection.first])
  else
    Factory.in(fv.first, intersection)
  end
end

#constant_variables ⇒ Object 



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# File 'lib/predicate/nodes/in.rb', line 43

def constant_variables
  if right.literal? and right.value.size == 1
    free_variables
  else
    []
  end
end

#constants ⇒ Object 



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# File 'lib/predicate/nodes/in.rb', line 51

def constants
  if right.literal? and right.value.size == 1
    { identifier.name => right.value.first }
  else
    {}
  end
end

#dyadic_priority ⇒ Object 



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# File 'lib/predicate/nodes/in.rb', line 59

def dyadic_priority
  800
end

#evaluate(tuple) ⇒ Object 



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# File 'lib/predicate/nodes/in.rb', line 63

def evaluate(tuple)
  values = right.evaluate(tuple)
  values.include?(identifier.evaluate(tuple))
end

#free_variables ⇒ Object 



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# File 'lib/predicate/nodes/in.rb', line 39

def free_variables
  @free_variables ||= identifier.free_variables
end

#left ⇒ Object Also known as: identifier 



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# File 'lib/predicate/nodes/in.rb', line 9

def left
  self[1]
end

#priority ⇒ Object 



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# File 'lib/predicate/nodes/in.rb', line 5

def priority
  80
end

#right ⇒ Object 



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# File 'lib/predicate/nodes/in.rb', line 14

def right
  self[2]
end