Re: How Perl decides where a variable ends and text starts: Match variables in string interpolation

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Re^2: How Perl decides where a variable ends and text starts: Match variables in string interpolation by BillKSmith (Monsignor) on Jul 23, 2021 at 00:49 UTC
I was almost certain that I had seen a counter-example, but you are right Variable names. Bill	[reply]
Re^3: How Perl decides where a variable ends and text starts: Match variables in string interpolation by davido (Cardinal) on Jul 23, 2021 at 17:02 UTC
There are symbolic refs, but you have to stay in the symbolic ref world. If you create `${'1_'}` as a symbolic reference, you have to continue to refer to it symbolically only. Perl barfs if you try to use it as `$1_` later on. Here's a working example, though: `{ no strict 'refs'; ${'1_'} = 100; print ${'1_'}, "\n"; }` [download] If you go on to dump the `%main::` hash you'll see the package global `$1_` does exist. Perl's syntax just doesn't support it as anything but a symbolic ref, I think. Dave	[reply] [d/l] [select]
Re^4: How Perl decides where a variable ends and text starts: Match variables in string interpolation by AnomalousMonk (Archbishop) on Jul 24, 2021 at 00:22 UTC
A more extreme example: `Win8 Strawberry 5.8.9.5 (32) Fri 07/23/2021 20:17:49 C:\@Work\Perl\monks >perl -Mstrict -Mwarnings -l { no strict 'refs'; ${'@-%^#$!+'} = 'Yikes!'; print ${'@-%^#$!+'}; } print "%main:: $main::{'@-%^#$!+'}"; ^Z Yikes! %main:: *main::@-%^#$!+` [download] Same behavior under Strawberry 5.30.3.1 64-bit. Give a man a fish: `<%-{-{-{-<`	[reply] [d/l] [select]
Re^4: How Perl decides where a variable ends and text starts: Match variables in string interpolation by LanX (Saint) on Jul 24, 2021 at 08:31 UTC
And this only works for package variables not private ones. FWIW there is a common use case for this "hack". The debugger is caching the code lines of the debugged file for introspection in such a "hidden" array, to avoid name conflicts with regular vars. Update: See https://perldoc.perl.org/perldebguts#Debugger-Internal-Variables for more. Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery}	[reply]


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