Re^2: Surprising Precedence/Context

That must explain this too,

#!/usr/bin/perl

use strict;
use warnings;

sub returnsTrueButExpectedFalse {return 1 and 0}

die if 1 and 0;                        #does not die, but
die if returnsTrueButExpectedFalse();  #does die here, surprisingly
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B::Deparse shows the return statement as this,

(return(1) and 0);
[download]

which isn't quite enough to say the return(1) happens before the 0 is evaluated. That must be what's happening though, from your reminder about flow control and and.

Thanks for the tip about B::Deparse.

Jim

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Re^3: Surprising Precedence/Context ("and" is "if") by LanX (Saint) on Jun 02, 2017 at 20:11 UTC
like AnoMonk explained, use the -p switch with B::Deparse to see more parens `D:\Users\lanx>perl -MO=Deparse,-p -e"sub { return 1 and 0 }" sub { ((return 1) and 0); } ; -e syntax OK` [download] Please note that -x7 or higher will also show the equivalence between `if` and `and` (albeit in the opposite direction) `D:\Users\lanx>perl -MO=Deparse,-p,-x7 -e"sub { 0 if return 1 }" sub { ((return 1) and 0); } ; -e syntax OK` [download] Cheers Rolf _{(addicted to the Perl Programming Language and ☆☆☆☆ :) Je suis Charlie!}	[reply] [d/l] [select]

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Re^3: Surprising Precedence/Context ("and" is "if")
by LanX (Saint) on Jun 02, 2017 at 20:11 UTC

B::Deparse

D:\Users\lanx>perl -MO=Deparse,-p -e"sub { return 1 and 0 }"
sub {
    ((return 1) and 0);
}
;
-e syntax OK
[download]

Please note that -x7 or higher will also show the equivalence between if and and (albeit in the opposite direction)

D:\Users\lanx>perl -MO=Deparse,-p,-x7 -e"sub { 0 if return 1 }"
sub {
   ((return 1) and 0);
}
;
-e syntax OK
[download]

Cheers Rolf
_{(addicted to the Perl Programming Language and ☆☆☆☆ :)

Je suis Charlie!}

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