in reply to Check exist of anonymous subroutine before calling it within regexp substitute?

Just to add something more on the table, here using the experimental (??{CODE}) 

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

# case 1
$_ = 'foo fooz bar';
s/(\w+)/$d{$1}?$d{$1}->($1):"$1"/ge; 
print "$_\n";

# case 2
$_ = 'foo fooz bar';
s/(\w+)(??{!$d{$1}})/$d{$1}->($1)/ge; 
print "$_\n";

__OUT__

[foo] fooz (bar)
[foo] [foo]z (bar)

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Re^2: Check exist of anonymous subroutine before calling it within regexp substitute?
by ikegami (Patriarch) on Oct 29, 2009 at 18:15 UTC
    That should be 
    s/(\w+)(?(?{ !$d{$1} })(?!))/$d{$1}->($1)/ge;

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    Your solution fails if the non-existant word is followed by a one ("1"). For example, try input "baz1".

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      ty, i confess that at a first look i didn't understand why, could you elaborate plz?
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        use strict;
use warnings;

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

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

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        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.

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        $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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Re^2: Check exist of anonymous subroutine before calling it within regexp substitute?
by jffry (Hermit) on Oct 29, 2009 at 18:32 UTC

    Is there a plain English name for the ??{CODE} syntactic element? It is hard as heck to google, and I'm not seeing it in Perl 5.10 docs. Is it a Perl 6 or 5.11 thing?

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