Module: DataTools::Enumerator

Included in:
Enumerator
Defined in:
lib/data_tools/enumerator.rb

Instance Method Summary collapse

Instance Method Details

#csvme(outputstream, fields, headers = fields) ⇒ Object 



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# File 'lib/data_tools/enumerator.rb', line 2

def csvme(outputstream, fields, headers = fields)
  outputstream.puts headers.to_csv
  each do |hash|
    outputstream.puts hash.pluck(fields).to_csv
  end
  outputstream.flush # otherwise missing rows might not get pushed out
  outputstream
rescue Errno::EPIPE
  # output was closed, that's fine
end

#lazy_map(&block) ⇒ Object 



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# File 'lib/data_tools/enumerator.rb', line 21

def lazy_map(&block)
  Enumerator.new do |yielder|
    self.each do |value|
      yielder.yield(block.call(value))
    end
  end
end

#lazy_select(&block) ⇒ Object 



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# File 'lib/data_tools/enumerator.rb', line 13

def lazy_select(&block)
  Enumerator.new do |yielder|
    self.each do |val|
      yielder.yield(val) if block.call(val)
    end
  end
end