Sha256: c7cfb686c75024cd43aa9fc16ca0f626c132046d30a2e0c2b3409f33fcff8e1e
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Size: 959 Bytes
Versions: 5
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Stored size: 959 Bytes
Contents
module Alf
module Algebra
class Summarize
include Operator
include Relational
include Unary
signature do |s|
s.argument :by, AttrList, []
s.argument :summarization, Summarization, {}
s.option :allbut, Boolean, false, "Summarize on all but specified attributes?"
end
def heading
@heading ||= begin
op_h = operand.heading.project(by, allbut)
op_h.merge(summarization.to_heading)
end
end
def keys
@keys ||= begin
attrs = operand.heading.to_attr_list.project(by, allbut)
operand.keys.select{|k| k.subset?(attrs) }.if_empty{ Keys[ attrs ] }
end
end
private
def _type_check(options)
no_unknown!(by - operand.attr_list)
no_name_clash!(operand.attr_list, summarization.to_attr_list)
end
end # class Summarize
end # module Algebra
end # module Alf
Version data entries
5 entries across 5 versions & 1 rubygems