From dunedimensia@gmail.com

Created by dunedimensia@gmail.com

Hello.

It seems that 'my' access both branches of ternary conditional operator(?).
Expected behavior​: only one branch of ternary op. is evaluated. (See code example and its output at the END)

Also 'my' fails to compile ternary op. to declare one of the variables which are in branches. It tries to declare a condition.
If uncomment, error is generated​:
Can't declare conditional expression in "my" at ternary_conditional_and_my.pl line 12, near ") ="
Execution of ternary_conditional_and_my.pl aborted due to compilation errors.

And 'local' do as expected.

Same behavior in version 5.28.0

#!/usr/bin/perl -wl

use strict;

my( $A, $B ) = ( 5, 7 );
our( $C, $D ) = ( 6, 8 );

for my $i ( 0 .. 1 ){
  print " " . "-" x 10;
  print " [$A],[$B]";
 
# my( $i ? $C : $D ) = '-';
# local( $i ? $C : $D ) = '-';
 
  $i ? ( my $A = '-' ) : ( my $B = '-' );
  $i ? ( local $C = '-' ) : ( local $D = '-' );
 
  print " [$A],[$B]";
  print " [$C],[$D]";
}

print "[$A],[$B]";
print "[$C],[$D]";

__END__
----------
[5],[7]
Use of uninitialized value $A in concatenation (.) or string at ternary_conditional_and_my.pl line 18.
[],[-]
[6],[-]
----------
[5],[7]
Use of uninitialized value $B in concatenation (.) or string at ternary_conditional_and_my.pl line 18.
[-],[]
[-],[8]
[5],[7]
[6],[8]

Flags:
    category=core
    severity=wishlist

Site configuration information for perl 5.18.2:

Configured by Debian Project at Tue Nov 20 16:49:55 UTC 2018.

Summary of my perl5 (revision 5 version 18 subversion 2) configuration:
   
  Platform:
    osname=linux, osvers=4.4.0-139-generic, archname=i686-linux-gnu-thread-multi-64int
    uname='linux lcy01-amd64-009 4.4.0-139-generic #165-ubuntu smp wed oct 24 10:58:50 utc 2018 i686 athlon i686 gnulinux '
    

From @Grinnz

This is intended behavior. "my" has a compile time behavior of declaring the variable in the current lexical scope, which will mask the variable from outside the scope regardless of the ternary. Assignment and "local" occur at runtime, as "local" is dynamically scoped.

-Dan

The RT System itself - Status changed from 'new' to 'open'