FM / perl5

/usr/share/perl5

Name	Size	Mode	Actions
Attribute/	-	0755	rm
B/	-	0755	rm
Class/	-	0755	rm
Compress/	-	0755	rm
Config/	-	0755	rm
CPAN/	-	0755	rm
DBM_Filter/	-	0755	rm
Devel/	-	0755	rm
encoding/	-	0755	rm
ExtUtils/	-	0755	rm
File/	-	0755	rm
Getopt/	-	0755	rm
I18N/	-	0755	rm
IO/	-	0755	rm
IPC/	-	0755	rm
Locale/	-	0755	rm
Math/	-	0755	rm
Memoize/	-	0755	rm
Module/	-	0755	rm
Net/	-	0755	rm
overload/	-	0755	rm
Pod/	-	0755	rm
pod/	-	0755	rm
Search/	-	0755	rm
Term/	-	0755	rm
Text/	-	0755	rm
Thread/	-	0755	rm
Tie/	-	0755	rm
Time/	-	0755	rm
Unicode/	-	0755	rm
unicore/	-	0755	rm
URI/	-	0755	rm
User/	-	0755	rm
vendor_perl/	-	0755	rm
warnings/	-	0755	rm
AnyDBM_File.pm	2618	0644	edit dl rm
AutoLoader.pm	15797	0644	edit dl rm
AutoSplit.pm	19637	0644	edit dl rm
autouse.pm	4238	0644	edit dl rm
base.pm	10961	0644	edit dl rm
Benchmark.pm	31026	0644	edit dl rm
blib.pm	2062	0644	edit dl rm
bytes.pm	3740	0644	edit dl rm
bytes_heavy.pl	758	0644	edit dl rm
charnames.pm	20931	0644	edit dl rm
CORE.pod	3188	0644	edit dl rm
DB.pm	18922	0644	edit dl rm
DBM_Filter.pm	14385	0644	edit dl rm
deprecate.pm	4603	0644	edit dl rm
diagnostics.pm	19299	0644	edit dl rm
DirHandle.pm	2085	0644	edit dl rm
Dumpvalue.pm	17668	0644	edit dl rm
dumpvar.pl	15555	0644	edit dl rm
English.pm	4761	0644	edit dl rm
feature.pm	19003	0644	edit dl rm
fields.pm	9475	0644	edit dl rm
FileCache.pm	5549	0644	edit dl rm
FileHandle.pm	6784	0644	edit dl rm
filetest.pm	4003	0644	edit dl rm
FindBin.pm	4561	0644	edit dl rm
if.pm	3611	0644	edit dl rm
integer.pm	3254	0644	edit dl rm
Internals.pod	2575	0644	edit dl rm
less.pm	3204	0644	edit dl rm
locale.pm	4855	0644	edit dl rm
Memoize.pm	36192	0644	edit dl rm
meta_notation.pm	2117	0644	edit dl rm
NEXT.pm	18985	0644	edit dl rm
open.pm	8512	0644	edit dl rm
overload.pm	53302	0644	edit dl rm
overloading.pm	1808	0644	edit dl rm
perl5db.pl	317094	0644	edit dl rm
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Safe.pm	25364	0644	edit dl rm
SelectSaver.pm	1076	0644	edit dl rm
SelfLoader.pm	17686	0644	edit dl rm
sigtrap.pm	8736	0644	edit dl rm
sort.pm	3911	0644	edit dl rm
strict.pm	4738	0644	edit dl rm
subs.pm	901	0644	edit dl rm
Symbol.pm	4799	0644	edit dl rm
Test.pm	30042	0644	edit dl rm
Thread.pm	8289	0644	edit dl rm
UNIVERSAL.pm	6594	0644	edit dl rm
URI.pm	34954	0644	edit dl rm
utf8.pm	10423	0644	edit dl rm
vars.pm	2458	0644	edit dl rm
vmsish.pm	4313	0644	edit dl rm
warnings.pm	50537	0644	edit dl rm
XSLoader.pm	11252	0644	edit dl rm
_charnames.pm	34151	0644	edit dl rm

Edit: /usr/share/perl5/integer.pm (3254B)

package integer;

our $VERSION = '1.01';

=head1 NAME

integer - Perl pragma to use integer arithmetic instead of floating point

=head1 SYNOPSIS

use integer;
    $x = 10/3;
    # $x is now 3, not 3.33333333333333333

=head1 DESCRIPTION

This tells the compiler to use integer operations from here to the end
of the enclosing BLOCK.  On many machines, this doesn't matter a great
deal for most computations, but on those without floating point
hardware, it can make a big difference in performance.

Note that this only affects how most of the arithmetic and relational
B<operators> handle their operands and results, and B<not> how all
numbers everywhere are treated.  Specifically, C<use integer;> has the
effect that before computing the results of the arithmetic operators
(+, -, *, /, %, +=, -=, *=, /=, %=, and unary minus), the comparison
operators (<, <=, >, >=, ==, !=, <=>), and the bitwise operators (|, &,
^, <<, >>, |=, &=, ^=, <<=, >>=), the operands have their fractional
portions truncated (or floored), and the result will have its
fractional portion truncated as well.  In addition, the range of
operands and results is restricted to that of familiar two's complement
integers, i.e., -(2**31) .. (2**31-1) on 32-bit architectures, and
-(2**63) .. (2**63-1) on 64-bit architectures.  For example, this code

use integer;
    $x = 5.8;
    $y = 2.5;
    $z = 2.7;
    $a = 2**31 - 1;  # Largest positive integer on 32-bit machines
    $, = ", ";
    print $x, -$x, $x+$y, $x-$y, $x/$y, $x*$y, $y==$z, $a, $a+1;

will print:  5.8, -5, 7, 3, 2, 10, 1, 2147483647, -2147483648

Note that $x is still printed as having its true non-integer value of
5.8 since it wasn't operated on.  And note too the wrap-around from the
largest positive integer to the largest negative one.   Also, arguments
passed to functions and the values returned by them are B<not> affected
by C<use integer;>.  E.g.,

srand(1.5);
    $, = ", ";
    print sin(.5), cos(.5), atan2(1,2), sqrt(2), rand(10);

will give the same result with or without C<use integer;>  The power
operator C<**> is also not affected, so that 2 ** .5 is always the
square root of 2.  Now, it so happens that the pre- and post- increment
and decrement operators, ++ and --, are not affected by C<use integer;>
either.  Some may rightly consider this to be a bug -- but at least it's
a long-standing one.

Finally, C<use integer;> also has an additional affect on the bitwise
operators.  Normally, the operands and results are treated as
B<unsigned> integers, but with C<use integer;> the operands and results
are B<signed>.  This means, among other things, that ~0 is -1, and -2 &
-5 is -6.

Internally, native integer arithmetic (as provided by your C compiler)
is used.  This means that Perl's own semantics for arithmetic
operations may not be preserved.  One common source of trouble is the
modulus of negative numbers, which Perl does one way, but your hardware
may do another.

% perl -le 'print (4 % -3)'
    -2
    % perl -Minteger -le 'print (4 % -3)'
    1

See L<perlmodlib/"Pragmatic Modules">, L<perlop/"Integer Arithmetic">

=cut

$integer::hint_bits = 0x1;

sub import {
    $^H |= $integer::hint_bits;
}

sub unimport {
    $^H &= ~$integer::hint_bits;
}

package integer; our $VERSION = '1.01'; =head1 NAME integer - Perl pragma to use integer arithmetic instead of floating point =head1 SYNOPSIS use integer; $x = 10/3; # $x is now 3, not 3.33333333333333333 =head1 DESCRIPTION This tells the compiler to use integer operations from here to the end of the enclosing BLOCK. On many machines, this doesn't matter a great deal for most computations, but on those without floating point hardware, it can make a big difference in performance. Note that this only affects how most of the arithmetic and relational B handle their operands and results, and B how all numbers everywhere are treated. Specifically, C has the effect that before computing the results of the arithmetic operators (+, -, *, /, %, +=, -=, *=, /=, %=, and unary minus), the comparison operators (<, <=, >, >=, ==, !=, <=>), and the bitwise operators (|, &, ^, <<, >>, |=, &=, ^=, <<=, >>=), the operands have their fractional portions truncated (or floored), and the result will have its fractional portion truncated as well. In addition, the range of operands and results is restricted to that of familiar two's complement integers, i.e., -(2**31) .. (2**31-1) on 32-bit architectures, and -(2**63) .. (2**63-1) on 64-bit architectures. For example, this code use integer; $x = 5.8; $y = 2.5; $z = 2.7; $a = 2**31 - 1; # Largest positive integer on 32-bit machines $, = ", "; print $x, -$x, $x+$y, $x-$y, $x/$y, $x*$y, $y==$z, $a, $a+1; will print: 5.8, -5, 7, 3, 2, 10, 1, 2147483647, -2147483648 Note that $x is still printed as having its true non-integer value of 5.8 since it wasn't operated on. And note too the wrap-around from the largest positive integer to the largest negative one. Also, arguments passed to functions and the values returned by them are B affected by C. E.g., srand(1.5); $, = ", "; print sin(.5), cos(.5), atan2(1,2), sqrt(2), rand(10); will give the same result with or without C The power operator C<**> is also not affected, so that 2 ** .5 is always the square root of 2. Now, it so happens that the pre- and post- increment and decrement operators, ++ and --, are not affected by C either. Some may rightly consider this to be a bug -- but at least it's a long-standing one. Finally, C also has an additional affect on the bitwise operators. Normally, the operands and results are treated as B integers, but with C the operands and results are B. This means, among other things, that ~0 is -1, and -2 & -5 is -6. Internally, native integer arithmetic (as provided by your C compiler) is used. This means that Perl's own semantics for arithmetic operations may not be preserved. One common source of trouble is the modulus of negative numbers, which Perl does one way, but your hardware may do another. % perl -le 'print (4 % -3)' -2 % perl -Minteger -le 'print (4 % -3)' 1 See L, L =cut $integer::hint_bits = 0x1; sub import { $^H |= $integer::hint_bits; } sub unimport { $^H &= ~$integer::hint_bits; } 1;