NAME
dec-pl - Decrement variable using Perl's auto-decrement notion
VERSION
This document describes version 0.001 of dec-pl (from Perl distribution App-IncrementUtils), released on 2019-01-25.
SYNOPSIS
% dec-pl B b00 2.3
A
a99
1.3
DESCRIPTION
This very simple script decrements its arguments using Perl module Data::Decrement, which basically tries to provide the counterpart to Perl's ++
(auto-increment) operator. The auto-increment rules, taken from perlop and copied here for convenience, are the following:
The auto-increment operator
has
a little extra builtin magic to it. If you
increment a variable that is numeric, or that
has
ever been used in a numeric
context, you get a normal increment. If, however, the variable
has
been used in
only string contexts since it was set, and
has
a value that is not the empty
string and matches the pattern
"/^[a-zA-Z]*[0-9]*\z/"
, the increment is done as
a string, preserving
each
character within its range,
with
carry:
++(
$foo
=
"99"
);
# prints "100"
++(
$foo
=
"a0"
);
# prints "a1"
++(
$foo
=
"Az"
);
# prints "Ba"
++(
$foo
=
"zz"
);
# prints "aaa"
"undef"
is always treated as numeric, and in particular is changed to 0
before
incrementing (so that a post-increment of an
undef
value will
return
0 rather
than
"undef"
).
The auto-decrement operator is not magical.
OPTIONS
--times=i (-n)
Specify how many times to decrement.
HOMEPAGE
Please visit the project's homepage at https://metacpan.org/release/App-IncrementUtils.
SOURCE
Source repository is at https://github.com/perlancar/perl-App-IncrementUtils.
BUGS
Please report any bugs or feature requests on the bugtracker website https://rt.cpan.org/Public/Dist/Display.html?Name=App-IncrementUtils
When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.
SEE ALSO
AUTHOR
perlancar <perlancar@cpan.org>
COPYRIGHT AND LICENSE
This software is copyright (c) 2019 by perlancar@cpan.org.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.