I have once or twice been bewildered by this feature, too. In addition to perlop, there is Freidl, who says in the Owls Book: "If no regex is given, such as with m// ... Perl reuses the regular expression most recently used successfully with in the enclosing dynamic scope. This used to be useful for efficiency reasons, but is now obsolete with the advent of regex objects."

This kind of thing keeps me humble, because I know that somewhere there is someone who understands exactly why this was a good idea.

In reply to Re: a word of warning about /$pattern/ by vacant
in thread a word of warning about /$pattern/ by dada

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