SPUG: Behavior of &&'ed functions (B::Deparse and perltidy)

David Dyck david.dyck at fluke.com
Wed Oct 27 18:48:33 CDT 2004

On Wed, 27 Oct 2004 at 13:20 -0700, John Costello <cos at indeterminate.net> wrote:

> Why does Perl (5.8.0) behave this way?

Don't you just had it when you start composing email
and forget to send it till it's too late :-)

I see you were already given a response, but I
want to follow up with a plug for 2 perl tools
that can help you understand what "perl is thinking"

I took your code perl6.pl and used Deparse to explain
how perl parses the code

 perl -MO=Deparse,-p test6.pl > test6p.pl

See perldoc B::Deparse for an explanation...
 When you use the -p option, the output also includes parentheses even
 when they are not required by precedence, which can make it easy to
 see if perl is parsing your expressions the way you intended.

Then I asked perltidy to pretty print the coutput
# see  http://perltidy.sourceforge.net

perltidy  test6p.pl
cat test6p.pl.tdy

use strict 'refs';
my ($column);
( $column = 0 );
        ( "column is: $column\n" && ( ++$column ) )
          && print("now column is: $column\n")
        ( "and column is: $column\n" && ( $column++ ) )
          && print("and now column is: $column\n")

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