class Bmg::Relation::Empty
The empty relation, of a given type.
This relation implementation exists mostly for optimization purposes, since knowing that a relation is empty allows simplifying many expressions.
Attributes
type[RW]
Public Class Methods
new(type)
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# File lib/bmg/relation/empty.rb, line 13 def initialize(type) @type = type end
Public Instance Methods
_count()
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# File lib/bmg/relation/empty.rb, line 22 def _count 0 end
each(&bl)
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# File lib/bmg/relation/empty.rb, line 19 def each(&bl) end
inspect()
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# File lib/bmg/relation/empty.rb, line 34 def inspect "(empty)" end
to_ast()
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# File lib/bmg/relation/empty.rb, line 26 def to_ast [ :empty ] end
to_s()
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# File lib/bmg/relation/empty.rb, line 30 def to_s "(empty)" end