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Re^2: Using Look-ahead and Look-behindby Roy Johnson (Monsignor)
|on Nov 12, 2007 at 17:54 UTC||Need Help??|
Generally, the decision about using ?: is not about whether it's necessary, but that capturing whatever you're grouping isn't necessary. The ?: modifier makes parentheses not capture, which is somewhat more efficient and might make the task of counting left parentheses less onerous.
By the way, it's not a lookaround feature.
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