While it is true that @( is a valid variable name, it doesn’t interpolate: 
@( = (42, 12);  # valid statement
print "@(";     # doesn’t print '4212' but '@('
print '@(';     # same as above (obviously)

[download]
Thus, the @ in the regex doesn’t need escaping, strictly speaking. I’d still recommend escaping it, for clarity and maintainability.

In reply to Re^2: Regex being stupid by Grimy
in thread Regex being stupid by AI Cowboy

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