Class: Alf::Algebra::Extend

Inherits:

Object

• Object
• Alf::Algebra::Extend

Includes:

Operator, Relational, Unary

Defined in:

lib/alf/algebra/operator/extend.rb

Instance Attribute Summary

Attributes included from Operator

#operands

Instance Method Summary

• #heading ⇒ Object
• #keys ⇒ Object

Methods included from Unary

included, #operand, #with_operand

Methods included from Relational

included

Methods included from Support::Registry

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

Methods included from Operator

#==, #dup, #hash, included, #initialize, #signature, #to_cog, #to_lispy, #to_relvar, #to_s, #type_check, #with_operands

Methods included from TypeCheck

#joinable_headings!, #no_name_clash!, #same_heading!, #type_check_error!, #valid_ordering!

Methods included from Operand

#attr_list, coerce, #resulting_type, #to_ascii_tree, #to_cog, #to_relation, #type_check

Instance Method Details

#heading ⇒ Object

# File 'lib/alf/algebra/operator/extend.rb', line 12

def heading
  @heading ||= operand.heading.merge(ext.to_heading)
end

#keys ⇒ Object

# File 'lib/alf/algebra/operator/extend.rb', line 16

def keys
  @keys ||= begin
    attrs = ext.to_attr_list
    operand.keys.reject{|k| k.intersect?(attrs) }
  end
end