Class: ArcFurnace::EnumeratorSource

Inherits:
Source show all
Defined in:
lib/arc-furnace/enumerator_source.rb

Instance Attribute Summary collapse

Attributes inherited from Node

#error_handler, #node_id, #params

Instance Method Summary collapse

Methods inherited from Source

#close, #finalize, #prepare, #row

Constructor Details

#initialize ⇒ EnumeratorSource

Returns a new instance of EnumeratorSource.



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# File 'lib/arc-furnace/enumerator_source.rb', line 9

def initialize
  @enumerator = build_enumerator
  preprocess
  advance
end

Instance Attribute Details

#value ⇒ Object (readonly)

Returns the value of attribute value.



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# File 'lib/arc-furnace/enumerator_source.rb', line 7

def value
  @value
end

Instance Method Details

#advance ⇒ Object 



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# File 'lib/arc-furnace/enumerator_source.rb', line 26

def advance
  @value =
    begin
      enumerator.next if enumerator
    rescue StopIteration
      @enumerator = nil
      nil
    end
end

#empty? ⇒ Boolean

Is this source empty?

Returns:

  • (Boolean) 


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# File 'lib/arc-furnace/enumerator_source.rb', line 22

def empty?
  !value
end

#preprocess ⇒ Object

Called after setting up the enumerator but before advancing it Use this to extract header rows for instance.



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# File 'lib/arc-furnace/enumerator_source.rb', line 17

def preprocess
  # nothing
end