Class: Alf::Algebra::Union

Inherits:
Object
  • Object
show all
Includes:
Binary, Operator, Relational
Defined in:
lib/alf-algebra/alf/algebra/operator/union.rb

Instance Attribute Summary

Attributes included from Operator

#operands

Attributes included from Support::Bindable

#connection

Instance Method Summary collapse

Methods included from Operator

#==, #bind, #dup, included, #initialize, #signature, #to_lispy, #to_relvar, #with_operands

Methods included from Support::Registry

#each, #listen, #listeners, #register, #registered

Methods included from Operand

#attr_list, coerce, #to_cog, #to_dot, #to_relation

Methods included from Support::Bindable

#bind, #bound?, #connection!

Methods included from Relational

included

Methods included from Binary

#common_attributes, #common_heading, included, #left, #right, #with_left, #with_right

Instance Method Details

#heading ⇒ Object 



9
10
11
 
# File 'lib/alf-algebra/alf/algebra/operator/union.rb', line 9

def heading
  @heading ||= left.heading + right.heading
end

#keys ⇒ Object 



13
14
15
 
# File 'lib/alf-algebra/alf/algebra/operator/union.rb', line 13

def keys
  @keys ||= Keys[ heading.to_attr_list ]
end