Sha256: 4f3ea9000b135102ccb655669015fa8a69db4fbd18d2ae2a48379f99b8136971
Contents?: true
Size: 793 Bytes
Versions: 5
Compression:
Stored size: 793 Bytes
Contents
module Alf
module Algebra
class Rank
include Operator
include Relational
include Unary
signature do |s|
s.argument :order, Ordering, []
s.argument :as, AttrName, :rank
end
def heading
@heading ||= operand.heading.merge(as => Integer)
end
def keys
@keys ||= begin
keys, selectors = operand.keys, order.to_attr_list
if keys.any?{|k| k.subset_of?(selectors) }
keys + [ AttrList[as] ]
else
keys
end
end
end
private
def _type_check(options)
valid_ordering!(order, operand.attr_list)
no_name_clash!(operand.attr_list, AttrList[as])
end
end # class Rank
end # module Algebra
end # module Alf
Version data entries
5 entries across 5 versions & 1 rubygems