/usr/share/perl/5.20.2/overload.pm is in perl-base 5.20.2-3+deb8u11.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 | package overload;
our $VERSION = '1.22';
%ops = (
with_assign => "+ - * / % ** << >> x .",
assign => "+= -= *= /= %= **= <<= >>= x= .=",
num_comparison => "< <= > >= == !=",
'3way_comparison' => "<=> cmp",
str_comparison => "lt le gt ge eq ne",
binary => '& &= | |= ^ ^=',
unary => "neg ! ~",
mutators => '++ --',
func => "atan2 cos sin exp abs log sqrt int",
conversion => 'bool "" 0+ qr',
iterators => '<>',
filetest => "-X",
dereferencing => '${} @{} %{} &{} *{}',
matching => '~~',
special => 'nomethod fallback =',
);
my %ops_seen;
for $category (keys %ops) {
$ops_seen{$_}++ for (split /\s+/, $ops{$category});
}
sub nil {}
sub OVERLOAD {
$package = shift;
my %arg = @_;
my ($sub, $fb);
*{$package . "::(("} = \&nil; # Make it findable via fetchmethod.
for (keys %arg) {
if ($_ eq 'fallback') {
for my $sym (*{$package . "::()"}) {
*$sym = \&nil; # Make it findable via fetchmethod.
$$sym = $arg{$_};
}
} else {
warnings::warnif("overload arg '$_' is invalid")
unless $ops_seen{$_};
$sub = $arg{$_};
if (not ref $sub) {
$ {$package . "::(" . $_} = $sub;
$sub = \&nil;
}
#print STDERR "Setting '$ {'package'}::\cO$_' to \\&'$sub'.\n";
*{$package . "::(" . $_} = \&{ $sub };
}
}
}
sub import {
$package = (caller())[0];
# *{$package . "::OVERLOAD"} = \&OVERLOAD;
shift;
$package->overload::OVERLOAD(@_);
}
sub unimport {
$package = (caller())[0];
shift;
*{$package . "::(("} = \&nil;
for (@_) {
warnings::warnif("overload arg '$_' is invalid")
unless $ops_seen{$_};
delete $ {$package . "::"}{$_ eq 'fallback' ? '()' : "(" .$_};
}
}
sub Overloaded {
my $package = shift;
$package = ref $package if ref $package;
mycan ($package, '()') || mycan ($package, '((');
}
sub ov_method {
my $globref = shift;
return undef unless $globref;
my $sub = \&{*$globref};
no overloading;
return $sub if !ref $sub or $sub != \&nil;
return shift->can($ {*$globref});
}
sub OverloadedStringify {
my $package = shift;
$package = ref $package if ref $package;
#$package->can('(""')
ov_method mycan($package, '(""'), $package
or ov_method mycan($package, '(0+'), $package
or ov_method mycan($package, '(bool'), $package
or ov_method mycan($package, '(nomethod'), $package;
}
sub Method {
my $package = shift;
if(ref $package) {
local $@;
local $!;
require Scalar::Util;
$package = Scalar::Util::blessed($package);
return undef if !defined $package;
}
#my $meth = $package->can('(' . shift);
ov_method mycan($package, '(' . shift), $package;
#return $meth if $meth ne \&nil;
#return $ {*{$meth}};
}
sub AddrRef {
no overloading;
"$_[0]";
}
*StrVal = *AddrRef;
sub mycan { # Real can would leave stubs.
my ($package, $meth) = @_;
local $@;
local $!;
require mro;
my $mro = mro::get_linear_isa($package);
foreach my $p (@$mro) {
my $fqmeth = $p . q{::} . $meth;
return \*{$fqmeth} if defined &{$fqmeth};
}
return undef;
}
%constants = (
'integer' => 0x1000, # HINT_NEW_INTEGER
'float' => 0x2000, # HINT_NEW_FLOAT
'binary' => 0x4000, # HINT_NEW_BINARY
'q' => 0x8000, # HINT_NEW_STRING
'qr' => 0x10000, # HINT_NEW_RE
);
use warnings::register;
sub constant {
# Arguments: what, sub
while (@_) {
if (@_ == 1) {
warnings::warnif ("Odd number of arguments for overload::constant");
last;
}
elsif (!exists $constants {$_ [0]}) {
warnings::warnif ("'$_[0]' is not an overloadable type");
}
elsif (!ref $_ [1] || "$_[1]" !~ /(^|=)CODE\(0x[0-9a-f]+\)$/) {
# Can't use C<ref $_[1] eq "CODE"> above as code references can be
# blessed, and C<ref> would return the package the ref is blessed into.
if (warnings::enabled) {
$_ [1] = "undef" unless defined $_ [1];
warnings::warn ("'$_[1]' is not a code reference");
}
}
else {
$^H{$_[0]} = $_[1];
$^H |= $constants{$_[0]};
}
shift, shift;
}
}
sub remove_constant {
# Arguments: what, sub
while (@_) {
delete $^H{$_[0]};
$^H &= ~ $constants{$_[0]};
shift, shift;
}
}
1;
__END__
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