Sha256: 421ff074c00fdb21de3f2bb453c47ef33266ad2a44228addbbae221b4e8564ab
Contents?: true
Size: 924 Bytes
Versions: 4
Compression:
Stored size: 924 Bytes
Contents
module Alf
module Algebra
class Unwrap
include Operator
include Relational
include Unary
signature do |s|
s.argument :attribute, AttrName, :wrapped
end
def heading
@heading ||= begin
op_h = operand.heading
type = op_h[attribute]
raise NotSupportedError unless type.respond_to?(:heading)
down_h = type.heading
op_h.allbut([attribute]).merge(down_h)
end
end
def keys
operand.keys
end
private
def _type_check(options)
ungrouped = operand.heading[attribute]
unless ungrouped.ancestors.include?(Tuple)
type_check_error!("not a tuple-valued attribute `#{attribute}` (#{ungrouped})")
end
no_name_clash!(operand.attr_list, ungrouped.heading.to_attr_list)
end
end # class Unwrap
end # module Algebra
end # module Alf
Version data entries
4 entries across 4 versions & 1 rubygems