Class: PiecePipe::MethodStep
Instance Attribute Summary
Attributes inherited from Step
Instance Method Summary collapse
-
#initialize(meth) ⇒ MethodStep
constructor
A new instance of MethodStep.
- #process(item) ⇒ Object
Methods inherited from Step
Constructor Details
#initialize(meth) ⇒ MethodStep
Returns a new instance of MethodStep.
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# File 'lib/piece_pipe/method_step.rb', line 3 def initialize(meth) raise "method cannot be nil" if meth.nil? raise "method must accept 1 or 2 arguments; it accepts #{meth.arity}" if meth.arity != 1 and meth.arity != 2 @method = meth end |
Instance Method Details
#process(item) ⇒ Object
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# File 'lib/piece_pipe/method_step.rb', line 11 def process(item) case @method.arity when 1 # The method takes 1 argument, which we assume to be the input item. # We also assume that the method RETURNS the ONLY item it wishes to produce. # Will always produce exactly 1 output, even if that's just nil. produce @method.call(item) when 2 # The method takes 2 arguments. Assume first is input item, second is "producer", # ie, a means for the method to produce 0, 1 or many outputs at its discretion. # (by calling producer.produce) # Return value of @method.call is NOT considered. @method.call item, self end end |