Re^3: Check exist of anonymous subroutine before calling it within regexp substitute?

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Re^4: Check exist of anonymous subroutine before calling it within regexp substitute? by ikegami (Patriarch) on Oct 30, 2009 at 14:53 UTC
`use strict; use warnings; my %d = ( foo => sub { "[@_]"; }, bar => sub { "(@_)"; }, ); $_ = 'baz1'; s/(\w+)(??{!$d{$1}})/$d{$1}->($1)/ge; print "$_\n";` [download] `Use of uninitialized value in subroutine entry at line 10. Can't use string ("") as a subroutine ref while "strict refs" in use a +t line 10.` [download] `$1` is is "`baz`", so `$d{$1}` is `undef`, so `!$d{$1}` is `1`, so the match tries to match "`1`". It does, so the replacement expression is executed.	[reply] [d/l] [select]

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Re^4: Check exist of anonymous subroutine before calling it within regexp substitute?
by ikegami (Patriarch) on Oct 30, 2009 at 14:53 UTC

use strict;
use warnings;

my %d = (
    foo => sub { "[@_]"; },
    bar => sub { "(@_)"; },
);

$_ = 'baz1';
s/(\w+)(??{!$d{$1}})/$d{$1}->($1)/ge; 
print "$_\n";
[download]

Use of uninitialized value in subroutine entry at line 10.
Can't use string ("") as a subroutine ref while "strict refs" in use a
+t line 10.
[download]

$1 is is "baz", so $d{$1} is undef, so !$d{$1} is 1, so the match tries to match "1". It does, so the replacement expression is executed.

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