Sha256: 74d554062ff451db1d8a3db8f02a1893dcf1a334915800b6d01046e6e4b7c412
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Size: 674 Bytes
Versions: 13
Compression:
Stored size: 674 Bytes
Contents
module Alf
class Aggregator
#
# Defines a `sum()` aggregation operator.
#
# Example:
#
# # direct ruby usage
# Alf::Aggregator.sum{ qty }.aggregate(...)
#
# # lispy
# (summarize :supplies, [:sid], :total => sum{ qty })
#
class Sum < Aggregator
# Returns 0 as least value.
#
# @see Aggregator::InstanceMethods#least
def least()
0
end
# Aggregates on a tuple occurence through `memo + val`
#
# @see Aggregator::InstanceMethods#_happens
def _happens(memo, val)
memo + val
end
end # class Sum
end # class Aggregator
end # module Alf
Version data entries
13 entries across 13 versions & 2 rubygems