Sha256: 56765a139b0c7562e57403b42f8e592ab32c1f28b487cc3c978ba2c5fbf80886
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Size: 1.35 KB
Versions: 28
Compression:
Stored size: 1.35 KB
Contents
module Bmg
class Summarizer
#
# ValueBy summarizer.
#
# Example:
#
# # direct ruby usage
# Bmg::Summarizer.value_by(:qty, :by => :serie).summarize(...)
#
class ValueBy < Summarizer
DEFAULT_OPTIONS = {
:symbolize => false
}
# Returns {} as least value.
def least
{}
end
# Collects the value
def happens(memo, tuple)
by = tuple[options[:by]]
by = by.to_sym if by && options[:symbolize]
misuse!(tuple, memo) if memo.has_key?(by)
memo.tap{|m|
m[by] = extract_value(tuple)
}
end
# Finalizes the computation.
def finalize(memo)
default_tuple.merge(memo)
end
private
def default_tuple
(options[:series] || []).each_with_object({}){|s,ss|
s_def = options[:default]
s = s.to_sym if s && options[:symbolize]
ss[s] = s_def
}
end
def misuse!(tuple, memo)
msg = "Summarizer.value_by: summarization key + the serie must form be a candidate key"
msg += "\n"
msg += " Tuple: #{tuple.inspect}"
msg += " Memo: #{memo.inspect}"
raise MisuseError, msg
end
end # class ValueBy
def self.value_by(*args, &bl)
ValueBy.new(*args, &bl)
end
end # class Summarizer
end # module Bmg
Version data entries
28 entries across 28 versions & 1 rubygems