The new pattern grammar stuff is cool. But, if Perl automatically builds the parse tree with no further work necessary by the programmer, won't that be slow? Perl can't detect that named captures (based on the subrule name) won't be used after the match succeeds, so it can't leave them out. We had all the flack about using $& and use English; when it wasn't needed, so even that one copying of the input string was an issue. Won't this stuff be orders of magnitude worse?

—John

In reply to Perl6 regex/pattern performance issues? by John M. Dlugosz

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