Sha256: 4c10a2591402cd3fa2a6a535e2d12f82ba6de954ee6d43d96b8c1954558ee7c6
Contents?: true
Size: 992 Bytes
Versions: 5
Compression:
Stored size: 992 Bytes
Contents
module Alf
module Engine
#
# Provides hash-based grouping.
#
class Group::Hash < Cog
# @return [Enumerable] The operand
attr_reader :operand
# @return [AttrList] Attributes to group
attr_reader :attributes
# @return [AttrName] Name of the new attribute
attr_reader :as
# @return [Boolean] Group all but specified attributes?
attr_reader :allbut
# Creates a Group::Hash instance
def initialize(operand, attributes, as, allbut)
@operand = operand
@attributes = attributes
@as = as
@allbut = allbut
end
# (see Cog#each)
def each(&block)
atr, alb = @attributes, @allbut
index = Materialize::Hash.new(operand, atr, !alb)
index.each_pair do |k,v|
grouped = Relation.new(Clip.new(v, atr, alb).to_set)
yield k.merge(@as => grouped)
end
end
end # class Group::Hash
end # module Engine
end # module Alf
Version data entries
5 entries across 5 versions & 1 rubygems