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1 definition found
 for unfold/fold
From The Free On-line Dictionary of Computing (30 December 2018) :

  unfold/fold
  
     A program transformation where a recursive call to a
     function is unfolded to an instance of the function's body
     and then later an instance of the function's body is replaced
     by a call.  E.g.
  
     	sumdouble l = sum (double l)
  
     	double l = case l of
     	           []   -> []
     		   x:xs -> 2*x + double xs
  
     	==> (unfold double)
  
     	sumdouble l = sum (case l of
     		           []   -> []
     			   x:xs -> 2*x : double xs)
  
     	==> (distribute over case)
  
     	sumdouble l = case l of
     		      []   -> sum []
     		      x:xs -> sum (2*x : double xs)
  
      	==> (unfold sum)
  
     	sumdouble l = case l of
     		      []   -> 0
     		      x:xs -> 2*x + sum (double xs)
  
      	==> (fold sumdouble)
  
     	sumdouble l = case l of
     		      []   -> 0
     		      x:xs -> 2*x + sumdouble xs
  
     (1994-11-03)
  

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