Sha256: 459df48982556212d372a2fa1deaaa63468a9f953d97abe06005af41ba339bd8
Contents?: true
Size: 967 Bytes
Versions: 5
Compression:
Stored size: 967 Bytes
Contents
module Alf
module Engine
#
# Autonumbers input tuples under a new `as` attribute. Autonumbering starts
# at 0.
#
# Example:
#
# operand = [
# {:name => "Jones"},
# {:name => "Smith"}
# ]
# Autonum.new(operand, :id).to_a
# # => [
# # {:name => "Jones", :id => 0},
# # {:name => "Smith", :id => 1}
# # ]
#
class Autonum < Cog
# @return [Enumerable] The operand
attr_reader :operand
# @return [Symbol] Name of the autonum attribute
attr_reader :as
# Creates an Autonum instance
def initialize(operand, as)
@operand = operand
@as = as
end
# (see Cog#each)
def each
autonum = 0
@operand.each do |tuple|
yield tuple.merge(@as => autonum)
autonum += 1
end
end
end # class Autonum
end # module Engine
end # module Alf
Version data entries
5 entries across 5 versions & 1 rubygems