Date: 08/02/05 (Code WTF)    Keywords: no keywords

Collection >> do: operation separatedBy: separator
	"Evaluate the  argument, operation, 
	for each of the receiver's elements, interspersed
	with evaluations of the  
	argument, separator. The separator is first 
	evaluated after the first element, and is not
	evaluated after the last element (i.e. it is not
	evaluated at all if there are less than two elements)." 

	| sep |

	"Switch to the real separator after first eval." 
	sep := [sep := separator].

	self do: [:e |
		sep value.
		operation value: e].
	sep := nil.

Source: http://www.livejournal.com/community/code_wtf/12990.html