Re^5: The True but Zero value?

Not only DBI. The E0 is documented in perlop at the flip flop:

#!/usr/bin/perl
use warnings;
use strict;

while (<DATA>) {
    if (my $flipflop = /start/ .. /end/) {
        print "$flipflop: $_";
    }
}

__DATA__
before
start
1
2
3
end
after
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Output:

1: start
2: 1
3: 2
4: 3
5E0: end
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($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,
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Re^6: The True but Zero value? by Marshall (Canon) on Mar 23, 2016 at 17:29 UTC
Yes, this is quite correct although here the string "5E0" is meaning something different that "zero but true". Here it means "hey, this is a special kind of Five!". But we get the same idea of expressing 2 things with a single return value. Here the idea expressed is that this is the "END" and the END value is 5. E0 means 10*0 which is "1" numerically. So, 5E0 is a way of saying 51. The E0 means that this is a "special Five" and indeed it is with the flip-flop operator. 0E0 is way of saying "01". And that this is a special zero. demerphq pointed out that 0E5 is also zero, the exponent doesn't matter. This means 0 105. However I see a certain simplicity to E0 (100)== 1.	[reply]

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Re^6: The True but Zero value?
by Marshall (Canon) on Mar 23, 2016 at 17:29 UTC

E0 means 10**0 which is "1" numerically.
So, 5E0 is a way of saying 5*1.
The E0 means that this is a "special Five" and indeed it is with the flip-flop operator.

0E0 is way of saying "0*1". And that this is a special zero.
demerphq pointed out that 0E5 is also zero, the exponent doesn't matter. This means 0 * 10**5. However I see a certain simplicity to E0 (10**0)== 1.

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