Class: Locomotive::RelationalAlgebra::Comparison
- Inherits:
-
Unary
- Object
- RelAlgAstNode
- Operator
- Unary
- Locomotive::RelationalAlgebra::Comparison
- Defined in:
- lib/locomotive/relational_algebra/operators/comparisons/basic_comparison.rb
Direct Known Subclasses
Equal, GreaterEqualThan, GreaterThan, LessEqualThan, LessThan
Instance Attribute Summary collapse
-
#item1 ⇒ Object
Returns the value of attribute item1.
-
#item2 ⇒ Object
Returns the value of attribute item2.
-
#res ⇒ Object
Returns the value of attribute res.
Attributes inherited from Operator
Attributes included from AstHelpers::AstNode
#kind, #left_child, #owner, #right_child, #value
Instance Method Summary collapse
- #child=(op) ⇒ Object
- #clone ⇒ Object
-
#initialize(op, res, items) ⇒ Comparison
constructor
A new instance of Comparison.
- #set(var, plan) ⇒ Object
- #xml_content ⇒ Object
Methods inherited from Operator
#bound, #free, #to_xml, #xml_kind, #xml_schema
Methods included from XML
Methods included from AstHelpers::Annotations
Methods included from AstHelpers::AstNode
#has_left_child?, #has_right_child?, #is_leaf?, #traverse, #traverse_strategy=
Constructor Details
#initialize(op, res, items) ⇒ Comparison
Returns a new instance of Comparison.
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# File 'lib/locomotive/relational_algebra/operators/comparisons/basic_comparison.rb', line 14 def initialize(op, res, items) self.res, self.item1, self.item2 = res, items[0], items[1] super(op) end |
Dynamic Method Handling
This class handles dynamic methods through the method_missing method in the class Locomotive::AstHelpers::Annotations
Instance Attribute Details
#item1 ⇒ Object
Returns the value of attribute item1.
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# File 'lib/locomotive/relational_algebra/operators/comparisons/basic_comparison.rb', line 7 def item1 @item1 end |
#item2 ⇒ Object
Returns the value of attribute item2.
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# File 'lib/locomotive/relational_algebra/operators/comparisons/basic_comparison.rb', line 7 def item2 @item2 end |
#res ⇒ Object
Returns the value of attribute res.
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# File 'lib/locomotive/relational_algebra/operators/comparisons/basic_comparison.rb', line 7 def res @res end |
Instance Method Details
#child=(op) ⇒ Object
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# File 'lib/locomotive/relational_algebra/operators/comparisons/basic_comparison.rb', line 21 def child=(op) unless op.schema.attributes?([self.item1]) raise CorruptedSchema, "Schema #{op.schema.attributes} does not " \ "contain all attributes of #{item1}." end unless op.schema.attributes?([self.item2]) raise CorruptedSchema, "Schema #{op.schema.attributes} does not " \ "contain all attributes of #{item2}." end self.schema = op.schema + Schema.new({ self.res => [RBool.instance]}) super(op) end |
#clone ⇒ Object
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# File 'lib/locomotive/relational_algebra/operators/comparisons/basic_comparison.rb', line 37 def clone self.class.new(child.clone, res.clone, [item1.clone, item2.clone]) end |
#set(var, plan) ⇒ Object
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# File 'lib/locomotive/relational_algebra/operators/comparisons/basic_comparison.rb', line 44 def set(var,plan) self.class.new( child.set(var,plan), res.clone, [item1.clone, item2.clone]) end |
#xml_content ⇒ Object
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# File 'lib/locomotive/relational_algebra/operators/comparisons/basic_comparison.rb', line 52 def xml_content content do [column(:name => res.to_xml, :new => true), column(:name => item1.to_xml, :new => false, :position => 1), column(:name => item2.to_xml, :new => false, :position => 2) ].join end end |