# -*- coding: utf-8-unix -*-
package Math::BigInt;
#
# "Mike had an infinite amount to do and a negative amount of time in which
# to do it." - Before and After
#
# The following hash values are used:
#
# sign : "+", "-", "+inf", "-inf", or "NaN"
# value : unsigned int with actual value ($LIB thingy)
# accuracy : accuracy (scalar)
# precision : precision (scalar)
# Remember not to take shortcuts ala $xs = $x->{value}; $LIB->foo($xs); since
# underlying lib might change the reference!
use 5.006001;
use strict;
use warnings;
use Carp qw< carp croak >;
use Scalar::Util qw< blessed refaddr >;
our $VERSION = '2.003001';
$VERSION =~ tr/_//d;
require Exporter;
our @ISA = qw(Exporter);
our @EXPORT_OK = qw(objectify bgcd blcm);
# Inside overload, the first arg is always an object. If the original code had
# it reversed (like $x = 2 * $y), then the third parameter is true.
# In some cases (like add, $x = $x + 2 is the same as $x = 2 + $x) this makes
# no difference, but in some cases it does.
# For overloaded ops with only one argument we simple use $_[0]->copy() to
# preserve the argument.
# Thus inheritance of overload operators becomes possible and transparent for
# our subclasses without the need to repeat the entire overload section there.
use overload
# overload key: with_assign
'+' => sub { $_[0] -> copy() -> badd($_[1]); },
'-' => sub { my $c = $_[0] -> copy();
$_[2] ? $c -> bneg() -> badd($_[1])
: $c -> bsub($_[1]); },
'*' => sub { $_[0] -> copy() -> bmul($_[1]); },
'/' => sub { $_[2] ? ref($_[0]) -> new($_[1]) -> bdiv($_[0])
: $_[0] -> copy() -> bdiv($_[1]); },
'%' => sub { $_[2] ? ref($_[0]) -> new($_[1]) -> bmod($_[0])
: $_[0] -> copy() -> bmod($_[1]); },
'**' => sub { $_[2] ? ref($_[0]) -> new($_[1]) -> bpow($_[0])
: $_[0] -> copy() -> bpow($_[1]); },
'<<' => sub { $_[2] ? ref($_[0]) -> new($_[1]) -> bblsft($_[0])
: $_[0] -> copy() -> bblsft($_[1]); },
'>>' => sub { $_[2] ? ref($_[0]) -> new($_[1]) -> bbrsft($_[0])
: $_[0] -> copy() -> bbrsft($_[1]); },
# overload key: assign
'+=' => sub { $_[0] -> badd($_[1]); },
'-=' => sub { $_[0] -> bsub($_[1]); },
'*=' => sub { $_[0] -> bmul($_[1]); },
'/=' => sub { scalar $_[0] -> bdiv($_[1]); },
'%=' => sub { $_[0] -> bmod($_[1]); },
'**=' => sub { $_[0] -> bpow($_[1]); },
'<<=' => sub { $_[0] -> bblsft($_[1]); },
'>>=' => sub { $_[0] -> bbrsft($_[1]); },
# 'x=' => sub { },
# '.=' => sub { },
# overload key: num_comparison
'<' => sub { $_[2] ? ref($_[0]) -> new($_[1]) -> blt($_[0])
: $_[0] -> blt($_[1]); },
'<=' => sub { $_[2] ? ref($_[0]) -> new($_[1]) -> ble($_[0])
: $_[0] -> ble($_[1]); },
'>' => sub { $_[2] ? ref($_[0]) -> new($_[1]) -> bgt($_[0])
: $_[0] -> bgt($_[1]); },
'>=' => sub { $_[2] ? ref($_[0]) -> new($_[1]) -> bge($_[0])
: $_[0] -> bge($_[1]); },
'==' => sub { $_[0] -> beq($_[1]); },
'!=' => sub { $_[0] -> bne($_[1]); },
# overload key: 3way_comparison
'<=>' => sub { my $cmp = $_[0] -> bcmp($_[1]);
defined($cmp) && $_[2] ? -$cmp : $cmp; },
'cmp' => sub { $_[2] ? "$_[1]" cmp $_[0] -> bstr()
: $_[0] -> bstr() cmp "$_[1]"; },
# overload key: str_comparison
# 'lt' => sub { $_[2] ? ref($_[0]) -> new($_[1]) -> bstrlt($_[0])
# : $_[0] -> bstrlt($_[1]); },
#
# 'le' => sub { $_[2] ? ref($_[0]) -> new($_[1]) -> bstrle($_[0])
# : $_[0] -> bstrle($_[1]); },
#
# 'gt' => sub { $_[2] ? ref($_[0]) -> new($_[1]) -> bstrgt($_[0])
# : $_[0] -> bstrgt($_[1]); },
#
# 'ge' => sub { $_[2] ? ref($_[0]) -> new($_[1]) -> bstrge($_[0])
# : $_[0] -> bstrge($_[1]); },
#
# 'eq' => sub { $_[0] -> bstreq($_[1]); },
#
# 'ne' => sub { $_[0] -> bstrne($_[1]); },
# overload key: binary
'&' => sub { $_[2] ? ref($_[0]) -> new($_[1]) -> band($_[0])
: $_[0] -> copy() -> band($_[1]); },
'&=' => sub { $_[0] -> band($_[1]); },
'|' => sub { $_[2] ? ref($_[0]) -> new($_[1]) -> bior($_[0])
: $_[0] -> copy() -> bior($_[1]); },
'|=' => sub { $_[0] -> bior($_[1]); },
'^' => sub { $_[2] ? ref($_[0]) -> new($_[1]) -> bxor($_[0])
: $_[0] -> copy() -> bxor($_[1]); },
'^=' => sub { $_[0] -> bxor($_[1]); },
# '&.' => sub { },
# '&.=' => sub { },
# '|.' => sub { },
# '|.=' => sub { },
# '^.' => sub { },
# '^.=' => sub { },
# overload key: unary
'neg' => sub { $_[0] -> copy() -> bneg(); },
# '!' => sub { },
'~' => sub { $_[0] -> copy() -> bnot(); },
# '~.' => sub { },
# overload key: mutators
'++' => sub { $_[0] -> binc() },
'--' => sub { $_[0] -> bdec() },
# overload key: func
'atan2' => sub { $_[2] ? ref($_[0]) -> new($_[1]) -> batan2($_[0])
: $_[0] -> copy() -> batan2($_[1]); },
'cos' => sub { $_[0] -> copy() -> bcos(); },
'sin' => sub { $_[0] -> copy() -> bsin(); },
'exp' => sub { $_[0] -> copy() -> bexp($_[1]); },
'abs' => sub { $_[0] -> copy() -> babs(); },
'log' => sub { $_[0] -> copy() -> blog(); },
'sqrt' => sub { $_[0] -> copy() -> bsqrt(); },
'int' => sub { $_[0] -> copy() -> bint(); },
# overload key: conversion
'bool' => sub { $_[0] -> is_zero() ? '' : 1; },
'""' => sub { $_[0] -> bstr(); },
'0+' => sub { $_[0] -> numify(); },
'=' => sub { $_[0] -> copy(); },
;
##############################################################################
# global constants, flags and accessory
# These vars are public, but their direct usage is not recommended, use the
# accessor methods instead
# $round_mode is 'even', 'odd', '+inf', '-inf', 'zero', 'trunc', or 'common'.
our $round_mode = 'even';
our $accuracy = undef;
our $precision = undef;
our $div_scale = 40;
our $upgrade = undef; # default is no upgrade
our $downgrade = undef; # default is no downgrade
# These are internally, and not to be used from the outside at all
our $_trap_nan = 0; # are NaNs ok? set w/ config()
our $_trap_inf = 0; # are infs ok? set w/ config()
my $nan = 'NaN'; # constants for easier life
# Module to do the low level math.
my $DEFAULT_LIB = 'Math::BigInt::Calc';
my $LIB;
# Has import() been called yet? This variable is needed to make "require" work.
my $IMPORT = 0;
##############################################################################
# the old code had $rnd_mode, so we need to support it, too
our $rnd_mode = 'even';
sub TIESCALAR {
my ($class) = @_;
bless \$round_mode, $class;
}
sub FETCH {
return $round_mode;
}
sub STORE {
$rnd_mode = (ref $_[0]) -> round_mode($_[1]);
}
BEGIN {
# tie to enable $rnd_mode to work transparently
tie $rnd_mode, 'Math::BigInt';
# set up some handy alias names
*is_pos = \&is_positive;
*is_neg = \&is_negative;
*as_number = \&as_int;
}
###############################################################################
# Configuration methods
###############################################################################
sub round_mode {
my $self = shift;
my $class = ref($self) || $self || __PACKAGE__;
# setter/mutator
if (@_) {
my $m = shift;
croak("The value for 'round_mode' must be defined")
unless defined $m;
croak("Unknown round mode '$m'")
unless $m =~ /^(even|odd|\+inf|\-inf|zero|trunc|common)$/;
if (ref($self) && exists $self -> {round_mode}) {
$self->{round_mode} = $m;
} else {
no strict 'refs';
${"${class}::round_mode"} = $m;
}
}
# getter/accessor
else {
if (ref($self) && exists $self -> {round_mode}) {
return $self->{round_mode};
} else {
no strict 'refs';
my $m = ${"${class}::round_mode"};
return defined($m) ? $m : $round_mode;
}
}
}
sub upgrade {
my $self = shift;
my $class = ref($self) || $self || __PACKAGE__;
# setter/mutator
if (@_) {
my $u = shift;
if (ref($self) && exists $self -> {upgrade}) {
$self -> {upgrade} = $u;
} else {
no strict 'refs';
${"${class}::upgrade"} = $u;
}
}
# getter/accessor
else {
if (ref($self) && exists $self -> {upgrade}) {
return $self -> {upgrade};
} else {
no strict 'refs';
return ${"${class}::upgrade"};
}
}
}
sub downgrade {
my $self = shift;
my $class = ref($self) || $self || __PACKAGE__;
# setter/mutator
if (@_) {
my $d = shift;
if (ref($self) && exists $self -> {downgrade}) {
$self -> {downgrade} = $d;
} else {
no strict 'refs';
${"${class}::downgrade"} = $d;
}
}
# getter/accessor
else {
if (ref($self) && exists $self -> {downgrade}) {
return $self -> {downgrade};
} else {
no strict 'refs';
return ${"${class}::downgrade"};
}
}
}
sub div_scale {
my $self = shift;
my $class = ref($self) || $self || __PACKAGE__;
# setter/mutator
if (@_) {
my $f = shift;
croak("The value for 'div_scale' must be defined") unless defined $f;
$f = $f -> can('numify') ? $f -> numify() : 0 + "$f" if ref($f);
# also croak on non-numerical
croak "div_scale must be a number, not '$f'"
unless $f =~/^[+-]?(?:\d+(?:\.\d*)?|\.\d+)(?:[Ee][+-]?\d+)?\z/;
croak "div_scale must be an integer, not '$f'"
if $f != int $f;
# It is not documented what div_scale <= 0 means, but Astro::Units sets
# div_scale to 0 and fails its tests if this is not supported. So we
# silently support div_scale = 0.
croak "div_scale must be positive, not '$f'" if $f < 0;
if (ref($self) && exists $self -> {div_scale}) {
$self -> {div_scale} = $f;
} else {
no strict 'refs';
${"${class}::div_scale"} = $f;
}
}
# getter/accessor
else {
if (ref($self) && exists $self -> {div_scale}) {
return $self -> {div_scale};
} else {
no strict 'refs';
my $f = ${"${class}::div_scale"};
return defined($f) ? $f : $div_scale;
}
}
}
sub accuracy {
my $x = shift;
my $class = ref($x) || $x || __PACKAGE__;
# setter/mutator
if (@_) {
my $a = shift;
if (defined $a) {
$a = $a -> can('numify') ? $a -> numify() : 0 + "$a" if ref($a);
croak "accuracy must be a number, not '$a'"
if $a !~ /^\s*[+-]?(?:\d+(?:\.\d*)?|\.\d+)(?:[Ee][+-]?\d+)?\s*\z/;
croak "accuracy must be an integer, not '$a'"
if $a != int $a;
}
if (ref($x)) {
$x = $x -> bround($a) if defined $a;
$x -> {precision} = undef; # clear instance P
$x -> {accuracy} = $a; # set instance A
} else {
no strict 'refs';
${"${class}::precision"} = undef; # clear class P
${"${class}::accuracy"} = $a; # set class A
}
}
# getter/accessor
else {
if (ref($x)) {
return $x -> {accuracy};
} else {
no strict 'refs';
return ${"${class}::accuracy"};
}
}
}
sub precision {
my $x = shift;
my $class = ref($x) || $x || __PACKAGE__;
# setter/mutator
if (@_) {
my $p = shift;
if (defined $p) {
$p = $p -> can('numify') ? $p -> numify() : 0 + "$p" if ref($p);
croak "precision must be a number, not '$p'"
if $p !~ /^\s*[+-]?(?:\d+(?:\.\d*)?|\.\d+)(?:[Ee][+-]?\d+)?\s*\z/;
croak "precision must be an integer, not '$p'"
if $p != int $p;
}
if (ref($x)) {
$x = $x -> bfround($p) if defined $p;
$x -> {accuracy} = undef; # clear instance A
$x -> {precision} = $p; # set instance P
} else {
no strict 'refs';
${"${class}::accuracy"} = undef; # clear class A
${"${class}::precision"} = $p; # set class P
}
}
# getter/accessor
else {
if (ref($x)) {
return $x -> {precision};
} else {
no strict 'refs';
return ${"${class}::precision"};
}
}
}
sub trap_inf {
my $self = shift;
my $class = ref($self) || $self || __PACKAGE__;
# setter/mutator
if (@_) {
my $b = shift() ? 1 : 0;
if (ref($self) && exists $self -> {trap_inf}) {
$self -> {trap_inf} = $b;
} else {
no strict 'refs';
${"${class}::_trap_inf"} = $b;
}
}
# getter/accessor
else {
if (ref($self) && exists $self -> {trap_inf}) {
return $self -> {trap_inf};
} else {
no strict 'refs';
return ${"${class}::_trap_inf"};
}
}
}
sub trap_nan {
my $self = shift;
my $class = ref($self) || $self || __PACKAGE__;
# setter/mutator
if (@_) {
my $b = shift() ? 1 : 0;
if (ref($self) && exists $self -> {trap_nan}) {
$self -> {trap_nan} = $b;
} else {
no strict 'refs';
${"${class}::_trap_nan"} = $b;
}
}
# getter/accessor
else {
if (ref($self) && exists $self -> {trap_nan}) {
return $self -> {trap_nan};
} else {
no strict 'refs';
return ${"${class}::_trap_nan"};
}
}
}
sub config {
# return (or set) configuration data.
my $class = shift || __PACKAGE__;
# setter/mutator
#
# $class -> config(var => value, ...)
# $class -> config({ var => value, ... })
if (@_ > 1 || (@_ == 1 && (ref($_[0]) eq 'HASH'))) {
# try to set given options as arguments from hash
# If the argument is a hash ref, make a copy of it, since keys will be
# deleted below and we don't want to modify the input hash.
my $args = ref($_[0]) eq 'HASH' ? { %{ $_[0] } }: { @_ };
# We use this special handling of accuracy and precision because
# accuracy() always sets precision to undef and precision() always sets
# accuracy to undef. With out this special treatment, the following
# would result in both accuracy and precision being undef.
#
# $x -> config(accuracy => 3, precision => undef)
croak "config(): both accuracy and precision are defined"
if defined($args -> {accuracy}) && defined ($args -> {precision});
if (defined $args -> {accuracy}) {
$class -> accuracy($args -> {accuracy});
} elsif (defined $args -> {precision}) {
$class -> precision($args -> {precision});
} else {
$class -> accuracy(undef); # also sets precision to undef
}
delete $args->{accuracy};
delete $args->{precision};
# Set any remaining keys.
foreach my $key (qw/
round_mode div_scale
upgrade downgrade
trap_inf trap_nan
/)
{
# use a method call to check argument
$class->$key($args->{$key}) if exists $args->{$key};
delete $args->{$key};
}
# If there are any keys left, they are invalid.
if (keys %$args) {
croak("Illegal key(s) '", join("', '", keys %$args),
"' passed to $class\->config()");
}
}
# Now build the full configuration.
my $cfg = {
lib => $LIB,
lib_version => $LIB -> VERSION(),
class => $class,
version => $class -> VERSION(),
};
foreach my $key (qw/
accuracy precision
round_mode div_scale
upgrade downgrade
trap_inf trap_nan
/)
{
$cfg->{$key} = $class -> $key();
}
# getter/accessor
#
# $class -> config("var")
if (@_ == 1 && (ref($_[0]) ne 'HASH')) {
return $cfg->{$_[0]};
}
$cfg;
}
sub _scale_a {
# select accuracy parameter based on precedence,
# used by bround() and bfround(), may return undef for scale (means no op)
my ($x, $scale, $mode) = @_;
$scale = $x->{accuracy} unless defined $scale;
my $class = ref($x);
$scale = $class -> accuracy() unless defined $scale;
$mode = $class -> round_mode() unless defined $mode;
if (defined $scale) {
$scale = $scale->can('numify') ? $scale->numify()
: "$scale" if ref($scale);
$scale = int($scale);
}
($scale, $mode);
}
sub _scale_p {
# select precision parameter based on precedence,
# used by bround() and bfround(), may return undef for scale (means no op)
my ($x, $scale, $mode) = @_;
$scale = $x->{precision} unless defined $scale;
my $class = ref($x);
$scale = $class -> precision() unless defined $scale;
$mode = $class -> round_mode() unless defined $mode;
if (defined $scale) {
$scale = $scale->can('numify') ? $scale->numify()
: "$scale" if ref($scale);
$scale = int($scale);
}
($scale, $mode);
}
###############################################################################
# Constructor methods
###############################################################################
sub new {
# Create a new Math::BigInt object from a string or another Math::BigInt
# object. See hash keys documented at top.
# The argument could be an object, so avoid ||, && etc. on it. This would
# cause costly overloaded code to be called. The only allowed ops are ref()
# and defined.
my $self = shift;
my $selfref = ref $self;
my $class = $selfref || $self;
# Make "require" work.
$class -> import() if $IMPORT == 0;
# Calling new() with no input arguments has been discouraged for more than
# 10 years, but people apparently still use it, so we still support it.
return $class -> bzero() unless @_;
my ($wanted, @r) = @_;
if (!defined($wanted)) {
#carp("Use of uninitialized value in new()")
# if warnings::enabled("uninitialized");
return $class -> bzero(@r);
}
if (!ref($wanted) && $wanted eq "") {
#carp(q|Argument "" isn't numeric in new()|)
# if warnings::enabled("numeric");
#return $class -> bzero(@r);
return $class -> bnan(@r);
}
# Initialize a new object.
$self = bless {}, $class;
# Math::BigInt or subclass
if (defined(blessed($wanted)) && $wanted -> isa(__PACKAGE__)) {
# Don't copy the accuracy and precision, because a new object should get
# them from the global configuration.
$self -> {sign} = $wanted -> {sign};
$self -> {value} = $LIB -> _copy($wanted -> {value});
$self = $self->round(@r)
unless @r >= 2 && !defined($r[0]) && !defined($r[1]);
return $self;
}
# Shortcut for non-zero scalar integers with no non-zero exponent.
if ($wanted =~
/ ^
( [+-]? ) # optional sign
( [1-9] [0-9]* ) # non-zero significand
( \.0* )? # ... with optional zero fraction
( [Ee] [+-]? 0+ )? # optional zero exponent
\z
/x)
{
my $sgn = $1;
my $abs = $2;
$self->{sign} = $sgn || '+';
$self->{value} = $LIB->_new($abs);
$self = $self->round(@r);
return $self;
}
# Handle Infs.
if ($wanted =~ / ^
\s*
( [+-]? )
inf (?: inity )?
\s*
\z
/ix)
{
my $sgn = $1 || '+';
return $class -> binf($sgn, @r);
}
# Handle explicit NaNs (not the ones returned due to invalid input).
if ($wanted =~ / ^
\s*
( [+-]? )
nan
\s*
\z
/ix)
{
return $class -> bnan(@r);
}
my @parts;
if (
# Handle hexadecimal numbers. We auto-detect hexadecimal numbers if they
# have a "0x", "0X", "x", or "X" prefix, cf. CORE::oct().
$wanted =~ /^\s*[+-]?0?[Xx]/ and
@parts = $class -> _hex_str_to_flt_lib_parts($wanted)
or
# Handle octal numbers. We auto-detect octal numbers if they have a
# "0o", "0O", "o", "O" prefix, cf. CORE::oct().
$wanted =~ /^\s*[+-]?0?[Oo]/ and
@parts = $class -> _oct_str_to_flt_lib_parts($wanted)
or
# Handle binary numbers. We auto-detect binary numbers if they have a
# "0b", "0B", "b", or "B" prefix, cf. CORE::oct().
$wanted =~ /^\s*[+-]?0?[Bb]/ and
@parts = $class -> _bin_str_to_flt_lib_parts($wanted)
or
# At this point, what is left are decimal numbers that aren't handled
# above and octal floating point numbers that don't have any of the
# "0o", "0O", "o", or "O" prefixes. First see if it is a decimal number.
@parts = $class -> _dec_str_to_flt_lib_parts($wanted)
or
# See if it is an octal floating point number. The extra check is
# included because _oct_str_to_flt_lib_parts() accepts octal numbers
# that don't have a prefix (this is needed to make it work with, e.g.,
# from_oct() that don't require a prefix). However, Perl requires a
# prefix for octal floating point literals. For example, "1p+0" is not
# valid, but "01p+0" and "0__1p+0" are.
$wanted =~ /^\s*[+-]?0_*\d/ and
@parts = $class -> _oct_str_to_flt_lib_parts($wanted))
{
# The value is an integer iff the exponent is non-negative.
if ($parts[2] eq '+') {
$self -> {sign} = $parts[0];
$self -> {value} = $LIB -> _lsft($parts[1], $parts[3], 10);
$self = $self->round(@r)
unless @r >= 2 && !defined($r[0]) && !defined($r[1]);
return $self;
}
# The value is not an integer, so upgrade if upgrading is enabled.
return $upgrade -> new($wanted, @r) if defined $upgrade;
}
# If we get here, the value is neither a valid decimal, binary, octal, or
# hexadecimal number. It is not explicit an Inf or a NaN either.
return $class -> bnan(@r);
}
# Create a Math::BigInt from a decimal string. This is an equivalent to
# from_hex(), from_oct(), and from_bin(). It is like new() except that it does
# not accept anything but a string representing a finite decimal number.
sub from_dec {
my $self = shift;
my $selfref = ref $self;
my $class = $selfref || $self;
# Make "require" work.
$class -> import() if $IMPORT == 0;
# Don't modify constant (read-only) objects.
return $self if $selfref && $self->modify('from_dec');
my $str = shift;
my @r = @_;
# If called as a class method, initialize a new object.
$self = $class -> bzero(@r) unless $selfref;
if (my @parts = $class -> _dec_str_to_flt_lib_parts($str)) {
# The value is an integer iff the exponent is non-negative.
if ($parts[2] eq '+') {
$self -> {sign} = $parts[0];
$self -> {value} = $LIB -> _lsft($parts[1], $parts[3], 10);
return $self -> round(@r);
}
# The value is not an integer, so upgrade if upgrading is enabled.
return $upgrade -> new($str, @r) if defined $upgrade;
}
return $self -> bnan(@r);
}
# Create a Math::BigInt from a hexadecimal string.
sub from_hex {
my $self = shift;
my $selfref = ref $self;
my $class = $selfref || $self;
# Make "require" work.
$class -> import() if $IMPORT == 0;
# Don't modify constant (read-only) objects.
return $self if $selfref && $self->modify('from_hex');
my $str = shift;
my @r = @_;
# If called as a class method, initialize a new object.
$self = $class -> bzero(@r) unless $selfref;
if (my @parts = $class -> _hex_str_to_flt_lib_parts($str)) {
# The value is an integer iff the exponent is non-negative.
if ($parts[2] eq '+') {
$self -> {sign} = $parts[0];
$self -> {value} = $LIB -> _lsft($parts[1], $parts[3], 10);
return $self -> round(@r);
}
# The value is not an integer, so upgrade if upgrading is enabled.
return $upgrade -> new($str, @r) if defined $upgrade;
}
return $self -> bnan(@r);
}
# Create a Math::BigInt from an octal string.
sub from_oct {
my $self = shift;
my $selfref = ref $self;
my $class = $selfref || $self;
# Make "require" work.
$class -> import() if $IMPORT == 0;
# Don't modify constant (read-only) objects.
return $self if $selfref && $self->modify('from_oct');
my $str = shift;
my @r = @_;
# If called as a class method, initialize a new object.
$self = $class -> bzero(@r) unless $selfref;
if (my @parts = $class -> _oct_str_to_flt_lib_parts($str)) {
# The value is an integer iff the exponent is non-negative.
if ($parts[2] eq '+') {
$self -> {sign} = $parts[0];
$self -> {value} = $LIB -> _lsft($parts[1], $parts[3], 10);
return $self -> round(@r);
}
# The value is not an integer, so upgrade if upgrading is enabled.
return $upgrade -> new($str, @r) if defined $upgrade;
}
return $self -> bnan(@r);
}
# Create a Math::BigInt from a binary string.
sub from_bin {
my $self = shift;
my $selfref = ref $self;
my $class = $selfref || $self;
# Make "require" work.
$class -> import() if $IMPORT == 0;
# Don't modify constant (read-only) objects.
return $self if $selfref && $self->modify('from_bin');
my $str = shift;
my @r = @_;
# If called as a class method, initialize a new object.
$self = $class -> bzero(@r) unless $selfref;
if (my @parts = $class -> _bin_str_to_flt_lib_parts($str)) {
# The value is an integer iff the exponent is non-negative.
if ($parts[2] eq '+') {
$self -> {sign} = $parts[0];
$self -> {value} = $LIB -> _lsft($parts[1], $parts[3], 10);
return $self -> round(@r);
}
# The value is not an integer, so upgrade if upgrading is enabled.
return $upgrade -> new($str, @r) if defined $upgrade;
}
return $self -> bnan(@r);
}
# Create a Math::BigInt from a byte string.
sub from_bytes {
my $self = shift;
my $selfref = ref $self;
my $class = $selfref || $self;
# Make "require" work.
$class -> import() if $IMPORT == 0;
# Don't modify constant (read-only) objects.
return $self if $selfref && $self->modify('from_bytes');
croak("from_bytes() requires a newer version of the $LIB library.")
unless $LIB->can('_from_bytes');
my $str = shift;
my @r = @_;
# If called as a class method, initialize a new object.
$self = $class -> bzero(@r) unless $selfref;
$self -> {sign} = '+';
$self -> {value} = $LIB -> _from_bytes($str);
return $self -> round(@r);
}
sub from_base {
my $self = shift;
my $selfref = ref $self;
my $class = $selfref || $self;
# Make "require" work.
$class -> import() if $IMPORT == 0;
# Don't modify constant (read-only) objects.
return $self if $selfref && $self->modify('from_base');
my ($str, $base, $cs, @r) = @_; # $cs is the collation sequence
$base = $class->new($base) unless ref($base);
croak("the base must be a finite integer >= 2")
if $base < 2 || ! $base -> is_int();
# If called as a class method, initialize a new object.
$self = $class -> bzero() unless $selfref;
# If no collating sequence is given, pass some of the conversions to
# methods optimized for those cases.
unless (defined $cs) {
return $self -> from_bin($str, @r) if $base == 2;
return $self -> from_oct($str, @r) if $base == 8;
return $self -> from_hex($str, @r) if $base == 16;
if ($base == 10) {
my $tmp = $class -> from_dec($str, @r);
$self -> {value} = $tmp -> {value};
$self -> {sign} = '+';
return $self -> bround(@r);
}
}
croak("from_base() requires a newer version of the $LIB library.")
unless $LIB->can('_from_base');
$self -> {sign} = '+';
$self -> {value}
= $LIB->_from_base($str, $base -> {value}, defined($cs) ? $cs : ());
return $self -> bround(@r);
}
sub from_base_num {
my $self = shift;
my $selfref = ref $self;
my $class = $selfref || $self;
# Make "require" work.
$class -> import() if $IMPORT == 0;
# Don't modify constant (read-only) objects.
return $self if $selfref && $self->modify('from_base_num');
# Make sure we have an array of non-negative, finite, numerical objects.
my $nums = shift;
$nums = [ @$nums ]; # create new reference
for my $i (0 .. $#$nums) {
# Make sure we have an object.
$nums -> [$i] = $class -> new($nums -> [$i])
unless defined(blessed($nums -> [$i]))
&& $nums -> [$i] -> isa(__PACKAGE__);
# Make sure we have a finite, non-negative integer.
croak "the elements must be finite non-negative integers"
if $nums -> [$i] -> is_neg() || ! $nums -> [$i] -> is_int();
}
my $base = shift;
$base = $class -> new($base)
unless defined(blessed($base)) && $base -> isa(__PACKAGE__);
my @r = @_;
# If called as a class method, initialize a new object.
$self = $class -> bzero(@r) unless $selfref;
croak("from_base_num() requires a newer version of the $LIB library.")
unless $LIB->can('_from_base_num');
$self -> {sign} = '+';
$self -> {value} = $LIB -> _from_base_num([ map { $_ -> {value} } @$nums ],
$base -> {value});
return $self -> round(@r);
}
sub bzero {
# create/assign '+0'
# Class::method(...) -> Class->method(...)
unless (@_ && (defined(blessed($_[0])) && $_[0] -> isa(__PACKAGE__) ||
$_[0] =~ /^[a-z]\w*(?:::[a-z]\w*)*$/i))
{
#carp "Using ", (caller(0))[3], "() as a function is deprecated;",
# " use is as a method instead";
unshift @_, __PACKAGE__;
}
my $self = shift;
my $selfref = ref $self;
my $class = $selfref || $self;
# Make "require" work.
$class -> import() if $IMPORT == 0;
# Don't modify constant (read-only) objects.
return $self if $selfref && $self->modify('bzero');
# Get the rounding parameters, if any.
my @r = @_;
# If called as a class method, initialize a new object.
$self = bless {}, $class unless $selfref;
$self->{sign} = '+';
$self->{value} = $LIB->_zero();
# If rounding parameters are given as arguments, use them. If no rounding
# parameters are given, and if called as a class method, initialize the new
# instance with the class variables.
if (@r) {
if (@r >= 2 && defined($r[0]) && defined($r[1])) {
carp "can't specify both accuracy and precision";
return $self -> bnan();
}
$self->{accuracy} = $_[0];
$self->{precision} = $_[1];
} elsif (!$selfref) {
$self->{accuracy} = $class -> accuracy();
$self->{precision} = $class -> precision();
}
return $self;
}
sub bone {
# Create or assign '+1' (or -1 if given sign '-').
# Class::method(...) -> Class->method(...)
unless (@_ && (defined(blessed($_[0])) && $_[0] -> isa(__PACKAGE__) ||
$_[0] =~ /^[a-z]\w*(?:::[a-z]\w*)*$/i))
{
#carp "Using ", (caller(0))[3], "() as a function is deprecated;",
# " use is as a method instead";
unshift @_, __PACKAGE__;
}
my $self = shift;
my $selfref = ref $self;
my $class = $selfref || $self;
# Make "require" work.
$class -> import() if $IMPORT == 0;
# Don't modify constant (read-only) objects.
return $self if $selfref && $self->modify('bone');
my ($sign, @r) = @_;
# Get the sign.
if (defined($_[0]) && $_[0] =~ /^\s*([+-])\s*$/) {
$sign = $1;
shift;
} else {
$sign = '+';
}
# If called as a class method, initialize a new object.
$self = bless {}, $class unless $selfref;
$self->{sign} = $sign;
$self->{value} = $LIB->_one();
# If rounding parameters are given as arguments, use them. If no rounding
# parameters are given, and if called as a class method, initialize the new
# instance with the class variables.
if (@r) {
if (@r >= 2 && defined($r[0]) && defined($r[1])) {
carp "can't specify both accuracy and precision";
return $self -> bnan();
}
$self->{accuracy} = $_[0];
$self->{precision} = $_[1];
} elsif (!$selfref) {
$self->{accuracy} = $class -> accuracy();
$self->{precision} = $class -> precision();
}
return $self;
}
sub binf {
# create/assign a '+inf' or '-inf'
# Class::method(...) -> Class->method(...)
unless (@_ && (defined(blessed($_[0])) && $_[0] -> isa(__PACKAGE__) ||
$_[0] =~ /^[a-z]\w*(?:::[a-z]\w*)*$/i))
{
#carp "Using ", (caller(0))[3], "() as a function is deprecated;",
# " use is as a method instead";
unshift @_, __PACKAGE__;
}
my $self = shift;
my $selfref = ref $self;
my $class = $selfref || $self;
{
no strict 'refs';
if (${"${class}::_trap_inf"}) {
croak("Tried to create +-inf in $class->binf()");
}
}
# Make "require" work.
$class -> import() if $IMPORT == 0;
# Don't modify constant (read-only) objects.
return $self if $selfref && $self->modify('binf');
# Get the sign.
my $sign = '+'; # default is to return positive infinity
if (defined($_[0]) && $_[0] =~ /^\s*([+-])(inf|$)/i) {
$sign = $1;
shift;
}
# Get the rounding parameters, if any.
my @r = @_;
# If called as a class method, initialize a new object.
$self = bless {}, $class unless $selfref;
$self -> {sign} = $sign . 'inf';
$self -> {value} = $LIB -> _zero();
# If rounding parameters are given as arguments, use them. If no rounding
# parameters are given, and if called as a class method, initialize the new
# instance with the class variables.
if (@r) {
if (@r >= 2 && defined($r[0]) && defined($r[1])) {
carp "can't specify both accuracy and precision";
return $self -> bnan();
}
$self->{accuracy} = $_[0];
$self->{precision} = $_[1];
} elsif (!$selfref) {
$self->{accuracy} = $class -> accuracy();
$self->{precision} = $class -> precision();
}
return $self;
}
sub bnan {
# create/assign a 'NaN'
# Class::method(...) -> Class->method(...)
unless (@_ && (defined(blessed($_[0])) && $_[0] -> isa(__PACKAGE__) ||
$_[0] =~ /^[a-z]\w*(?:::[a-z]\w*)*$/i))
{
#carp "Using ", (caller(0))[3], "() as a function is deprecated;",
# " use is as a method instead";
unshift @_, __PACKAGE__;
}
my $self = shift;
my $selfref = ref($self);
my $class = $selfref || $self;
{
no strict 'refs';
if (${"${class}::_trap_nan"}) {
croak("Tried to create NaN in $class->bnan()");
}
}
# Make "require" work.
$class -> import() if $IMPORT == 0;
# Don't modify constant (read-only) objects.
return $self if $selfref && $self->modify('bnan');
# Get the rounding parameters, if any.
my @r = @_;
$self = bless {}, $class unless $selfref;
$self -> {sign} = $nan;
$self -> {value} = $LIB -> _zero();
# If rounding parameters are given as arguments, use them. If no rounding
# parameters are given, and if called as a class method, initialize the new
# instance with the class variables.
if (@r) {
if (@r >= 2 && defined($r[0]) && defined($r[1])) {
carp "can't specify both accuracy and precision";
return $self -> bnan();
}
$self->{accuracy} = $_[0];
$self->{precision} = $_[1];
} elsif (!$selfref) {
$self->{accuracy} = $class -> accuracy();
$self->{precision} = $class -> precision();
}
return $self;
}
sub bpi {
# Class::method(...) -> Class->method(...)
unless (@_ && (defined(blessed($_[0])) && $_[0] -> isa(__PACKAGE__) ||
$_[0] =~ /^[a-z]\w*(?:::[a-z]\w*)*$/i))
{
#carp "Using ", (caller(0))[3], "() as a function is deprecated;",
# " use is as a method instead";
unshift @_, __PACKAGE__;
}
# Called as Argument list
# --------- -------------
# Math::BigFloat->bpi() ("Math::BigFloat")
# Math::BigFloat->bpi(10) ("Math::BigFloat", 10)
# $x->bpi() ($x)
# $x->bpi(10) ($x, 10)
# Math::BigFloat::bpi() ()
# Math::BigFloat::bpi(10) (10)
#
# In ambiguous cases, we favour the OO-style, so the following case
#
# $n = Math::BigFloat->new("10");
# $x = Math::BigFloat->bpi($n);
#
# which gives an argument list with the single element $n, is resolved as
#
# $n->bpi();
my $self = shift;
my $selfref = ref $self;
my $class = $selfref || $self;
my @r = @_; # rounding paramters
# Make "require" work.
$class -> import() if $IMPORT == 0;
if ($selfref) { # bpi() called as an instance method
return $self if $self -> modify('bpi');
} else { # bpi() called as a class method
$self = bless {}, $class; # initialize new instance
}
return $upgrade -> bpi(@r) if defined $upgrade;
# hard-wired to "3"
$self -> {sign} = '+';
$self -> {value} = $LIB -> _new("3");
$self = $self -> round(@r);
return $self;
}
sub copy {
my ($x, $class);
if (ref($_[0])) { # $y = $x -> copy()
$x = shift;
$class = ref($x);
} else { # $y = Math::BigInt -> copy($y)
$class = shift;
$x = shift;
}
carp "Rounding is not supported for ", (caller(0))[3], "()" if @_;
my $copy = bless {}, $class;
$copy->{sign} = $x->{sign};
$copy->{value} = $LIB->_copy($x->{value});
$copy->{accuracy} = $x->{accuracy} if exists $x->{accuracy};
$copy->{precision} = $x->{precision} if exists $x->{precision};
return $copy;
}
sub as_int {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
return $x -> copy() if $x -> isa("Math::BigInt");
# Disable upgrading and downgrading.
my $upg = Math::BigInt -> upgrade();
my $dng = Math::BigInt -> downgrade();
Math::BigInt -> upgrade(undef);
Math::BigInt -> downgrade(undef);
# Copy the value.
my $y = Math::BigInt -> new($x);
# Copy the remaining instance variables.
($y->{accuracy}, $y->{precision}) = ($x->{accuracy}, $x->{precision});
# Restore upgrading and downgrading
Math::BigInt -> upgrade($upg);
Math::BigInt -> downgrade($dng);
return $y;
}
sub as_float {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
# Disable upgrading and downgrading.
require Math::BigFloat;
my $upg = Math::BigFloat -> upgrade();
my $dng = Math::BigFloat -> downgrade();
Math::BigFloat -> upgrade(undef);
Math::BigFloat -> downgrade(undef);
# Copy the value.
my $y = Math::BigFloat -> new($x);
# Copy the remaining instance variables.
($y->{accuracy}, $y->{precision}) = ($x->{accuracy}, $x->{precision});
# Restore upgrading and downgrading..
Math::BigFloat -> upgrade($upg);
Math::BigFloat -> downgrade($dng);
return $y;
}
sub as_rat {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
# Disable upgrading and downgrading.
require Math::BigRat;
my $upg = Math::BigRat -> upgrade();
my $dng = Math::BigRat -> downgrade();
Math::BigRat -> upgrade(undef);
Math::BigRat -> downgrade(undef);
my $y = Math::BigRat -> new($x);
# Copy the remaining instance variables.
($y->{accuracy}, $y->{precision}) = ($x->{accuracy}, $x->{precision});
# Restore upgrading and downgrading.
Math::BigRat -> upgrade($upg);
Math::BigRat -> downgrade($dng);
return $y;
}
###############################################################################
# Boolean methods
###############################################################################
sub is_zero {
# return true if arg (BINT or num_str) is zero (array '+', '0')
my (undef, $x) = ref($_[0]) ? (undef, @_) : objectify(1, @_);
return 0 if $x->{sign} !~ /^\+$/; # -, NaN & +-inf aren't
$LIB->_is_zero($x->{value});
}
sub is_one {
# return true if arg (BINT or num_str) is +1, or -1 if sign is given
my (undef, $x, $sign) = ref($_[0]) ? (undef, @_) : objectify(1, @_);
$sign = '+' if !defined($sign) || $sign ne '-';
return 0 if $x->{sign} ne $sign; # -1 != +1, NaN, +-inf aren't either
$LIB->_is_one($x->{value});
}
sub is_finite {
my (undef, $x) = ref($_[0]) ? (undef, @_) : objectify(1, @_);
return $x->{sign} eq '+' || $x->{sign} eq '-';
}
sub is_inf {
# return true if arg (BINT or num_str) is +-inf
my (undef, $x, $sign) = ref($_[0]) ? (undef, @_) : objectify(1, @_);
if (defined $sign) {
$sign = '[+-]inf' if $sign eq ''; # +- doesn't matter, only that's inf
$sign = "[$1]inf" if $sign =~ /^([+-])(inf)?$/; # extract '+' or '-'
return $x->{sign} =~ /^$sign$/ ? 1 : 0;
}
$x->{sign} =~ /^[+-]inf$/ ? 1 : 0; # only +-inf is infinity
}
sub is_nan {
# return true if arg (BINT or num_str) is NaN
my (undef, $x) = ref($_[0]) ? (undef, @_) : objectify(1, @_);
$x->{sign} eq $nan ? 1 : 0;
}
sub is_positive {
# return true when arg (BINT or num_str) is positive (> 0)
my (undef, $x) = ref($_[0]) ? (undef, @_) : objectify(1, @_);
return 1 if $x->{sign} eq '+inf'; # +inf is positive
# 0+ is neither positive nor negative
($x->{sign} eq '+' && !$x->is_zero()) ? 1 : 0;
}
sub is_negative {
# return true when arg (BINT or num_str) is negative (< 0)
my (undef, $x) = ref($_[0]) ? (undef, @_) : objectify(1, @_);
$x->{sign} =~ /^-/ ? 1 : 0; # -inf is negative, but NaN is not
}
sub is_non_negative {
# Return true if argument is non-negative (>= 0).
my (undef, $x) = ref($_[0]) ? (undef, @_) : objectify(1, @_);
return 1 if $x->{sign} =~ /^\+/;
return 1 if $x -> is_zero();
return 0;
}
sub is_non_positive {
# Return true if argument is non-positive (<= 0).
my (undef, $x) = ref($_[0]) ? (undef, @_) : objectify(1, @_);
return 1 if $x->{sign} =~ /^\-/;
return 1 if $x -> is_zero();
return 0;
}
sub is_odd {
# return true when arg (BINT or num_str) is odd, false for even
my (undef, $x) = ref($_[0]) ? (undef, @_) : objectify(1, @_);
return 0 if $x->{sign} !~ /^[+-]$/; # NaN & +-inf aren't
$LIB->_is_odd($x->{value});
}
sub is_even {
# return true when arg (BINT or num_str) is even, false for odd
my (undef, $x) = ref($_[0]) ? (undef, @_) : objectify(1, @_);
return 0 if $x->{sign} !~ /^[+-]$/; # NaN & +-inf aren't
$LIB->_is_even($x->{value});
}
sub is_int {
# return true when arg (BINT or num_str) is an integer
my (undef, $x) = ref($_[0]) ? (undef, @_) : objectify(1, @_);
$x->{sign} =~ /^[+-]$/ ? 1 : 0; # inf/-inf/NaN aren't
}
###############################################################################
# Comparison methods
###############################################################################
sub bcmp {
# Compares 2 values. Returns one of undef, <0, =0, >0. (suitable for sort)
# (BINT or num_str, BINT or num_str) return cond_code
# set up parameters
my ($class, $x, $y, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (ref($_[0]), @_)
: objectify(2, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
return $upgrade->bcmp($x, $y)
if defined($upgrade) && (!$x->isa(__PACKAGE__) || !$y->isa(__PACKAGE__));
if (($x->{sign} !~ /^[+-]$/) || ($y->{sign} !~ /^[+-]$/)) {
# handle +-inf and NaN
return if (($x->{sign} eq $nan) || ($y->{sign} eq $nan));
return 0 if $x->{sign} eq $y->{sign} && $x->{sign} =~ /^[+-]inf$/;
return +1 if $x->{sign} eq '+inf';
return -1 if $x->{sign} eq '-inf';
return -1 if $y->{sign} eq '+inf';
return +1;
}
# check sign for speed first
return 1 if $x->{sign} eq '+' && $y->{sign} eq '-'; # does also 0 <=> -y
return -1 if $x->{sign} eq '-' && $y->{sign} eq '+'; # does also -x <=> 0
# have same sign, so compare absolute values. Don't make tests for zero
# here because it's actually slower than testing in Calc (especially w/ Pari
# et al)
# post-normalized compare for internal use (honors signs)
if ($x->{sign} eq '+') {
# $x and $y both > 0
return $LIB->_acmp($x->{value}, $y->{value});
}
# $x && $y both < 0
$LIB->_acmp($y->{value}, $x->{value}); # swapped acmp (lib returns 0, 1, -1)
}
sub bacmp {
# Compares 2 values, ignoring their signs.
# Returns one of undef, <0, =0, >0. (suitable for sort)
# (BINT, BINT) return cond_code
# set up parameters
my ($class, $x, $y, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (ref($_[0]), @_)
: objectify(2, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
return $upgrade->bacmp($x, $y)
if defined($upgrade) && (!$x->isa(__PACKAGE__) || !$y->isa(__PACKAGE__));
if (($x->{sign} !~ /^[+-]$/) || ($y->{sign} !~ /^[+-]$/)) {
# handle +-inf and NaN
return if (($x->{sign} eq $nan) || ($y->{sign} eq $nan));
return 0 if $x->{sign} =~ /^[+-]inf$/ && $y->{sign} =~ /^[+-]inf$/;
return 1 if $x->{sign} =~ /^[+-]inf$/ && $y->{sign} !~ /^[+-]inf$/;
return -1;
}
$LIB->_acmp($x->{value}, $y->{value}); # lib does only 0, 1, -1
}
sub beq {
my (undef, $x, $y, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (undef, @_)
: objectify(2, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
my $cmp = $x -> bcmp($y); # bcmp() upgrades if necessary
return defined($cmp) && !$cmp;
}
sub bne {
my (undef, $x, $y, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (undef, @_)
: objectify(2, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
my $cmp = $x -> bcmp($y); # bcmp() upgrades if necessary
return defined($cmp) && !$cmp ? '' : 1;
}
sub blt {
my (undef, $x, $y, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (undef, @_)
: objectify(2, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
my $cmp = $x -> bcmp($y); # bcmp() upgrades if necessary
return defined($cmp) && $cmp < 0;
}
sub ble {
my (undef, $x, $y, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (undef, @_)
: objectify(2, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
my $cmp = $x -> bcmp($y); # bcmp() upgrades if necessary
return defined($cmp) && $cmp <= 0;
}
sub bgt {
my (undef, $x, $y, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (undef, @_)
: objectify(2, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
my $cmp = $x -> bcmp($y); # bcmp() upgrades if necessary
return defined($cmp) && $cmp > 0;
}
sub bge {
my (undef, $x, $y, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (undef, @_)
: objectify(2, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
my $cmp = $x -> bcmp($y); # bcmp() upgrades if necessary
return defined($cmp) && $cmp >= 0;
}
###############################################################################
# Arithmetic methods
###############################################################################
sub bneg {
# (BINT or num_str) return BINT
# negate number or make a negated number from string
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
return $x if $x->modify('bneg');
return $upgrade -> bneg($x, @r)
if defined($upgrade) && !$x->isa(__PACKAGE__);
# Don't negate +0 so we always have the normalized form +0. Does nothing for
# 'NaN'.
$x->{sign} =~ tr/+-/-+/
unless $x->{sign} eq '+' && $LIB->_is_zero($x->{value});
$x -> round(@r);
}
sub babs {
# (BINT or num_str) return BINT
# make number absolute, or return absolute BINT from string
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
return $x if $x->modify('babs');
# This call to the upgrade class must either be commented out or the method
# must be implemented in the upgrade class(es) to avoid infinite recursion.
# It doesn't help to check whether $x isa $upgrade, because there might be
# several levels of upgrading. Also see the test file t/upgrade2.t
#return $upgrade -> babs($x, @r)
# if defined($upgrade) && !$x->isa(__PACKAGE__);
$x->{sign} =~ s/^-/+/;
$x -> round(@r);
}
sub bsgn {
# Signum function.
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
return $x if $x->modify('bsgn');
# This call to the upgrade class must either be commented out or the method
# must be implemented in the upgrade class(es) to avoid infinite recursion.
# It doesn't help to check whether $x isa $upgrade, because there might be
# several levels of upgrading. Also see the test file t/upgrade2.t
#return $upgrade -> bsgn($x, @r)
# if defined($upgrade) && !$x->isa(__PACKAGE__);
return $x -> bone("+", @r) if $x -> is_pos();
return $x -> bone("-", @r) if $x -> is_neg();
$x -> round(@r);
}
sub bnorm {
# (numstr or BINT) return BINT
# Normalize number -- no-op here
my ($class, $x, @r) = ref($_[0]) ? (undef, $_[0]) : objectify(1, @_);
# This method is called from the rounding methods, so if this method
# supports rounding by calling the rounding methods, we get an infinite
# recursion.
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
$x;
}
sub binc {
# increment arg by one
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
return $x if $x->modify('binc');
return $x->round(@r) if $x -> is_inf() || $x -> is_nan();
return $upgrade -> binc($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
if ($x->{sign} eq '+') {
$x->{value} = $LIB->_inc($x->{value});
} elsif ($x->{sign} eq '-') {
$x->{value} = $LIB->_dec($x->{value});
$x->{sign} = '+' if $LIB->_is_zero($x->{value}); # -1 +1 => -0 => +0
}
return $x->round(@r);
}
sub bdec {
# decrement arg by one
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
return $x if $x->modify('bdec');
return $x->round(@r) if $x -> is_inf() || $x -> is_nan();
return $upgrade -> bdec($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);;
if ($x->{sign} eq '-') {
$x->{value} = $LIB->_inc($x->{value});
} elsif ($x->{sign} eq '+') {
if ($LIB->_is_zero($x->{value})) { # +1 - 1 => +0
$x->{value} = $LIB->_one();
$x->{sign} = '-';
} else {
$x->{value} = $LIB->_dec($x->{value});
}
}
return $x->round(@r);
}
#sub bstrcmp {
# my $self = shift;
# my $selfref = ref $self;
# my $class = $selfref || $self;
#
# croak 'bstrcmp() is an instance method, not a class method'
# unless $selfref;
# croak 'Wrong number of arguments for bstrcmp()' unless @_ == 1;
#
# return $self -> bstr() CORE::cmp shift;
#}
#
#sub bstreq {
# my $self = shift;
# my $selfref = ref $self;
# my $class = $selfref || $self;
#
# croak 'bstreq() is an instance method, not a class method'
# unless $selfref;
# croak 'Wrong number of arguments for bstreq()' unless @_ == 1;
#
# my $cmp = $self -> bstrcmp(shift);
# return defined($cmp) && ! $cmp;
#}
#
#sub bstrne {
# my $self = shift;
# my $selfref = ref $self;
# my $class = $selfref || $self;
#
# croak 'bstrne() is an instance method, not a class method'
# unless $selfref;
# croak 'Wrong number of arguments for bstrne()' unless @_ == 1;
#
# my $cmp = $self -> bstrcmp(shift);
# return defined($cmp) && ! $cmp ? '' : 1;
#}
#
#sub bstrlt {
# my $self = shift;
# my $selfref = ref $self;
# my $class = $selfref || $self;
#
# croak 'bstrlt() is an instance method, not a class method'
# unless $selfref;
# croak 'Wrong number of arguments for bstrlt()' unless @_ == 1;
#
# my $cmp = $self -> bstrcmp(shift);
# return defined($cmp) && $cmp < 0;
#}
#
#sub bstrle {
# my $self = shift;
# my $selfref = ref $self;
# my $class = $selfref || $self;
#
# croak 'bstrle() is an instance method, not a class method'
# unless $selfref;
# croak 'Wrong number of arguments for bstrle()' unless @_ == 1;
#
# my $cmp = $self -> bstrcmp(shift);
# return defined($cmp) && $cmp <= 0;
#}
#
#sub bstrgt {
# my $self = shift;
# my $selfref = ref $self;
# my $class = $selfref || $self;
#
# croak 'bstrgt() is an instance method, not a class method'
# unless $selfref;
# croak 'Wrong number of arguments for bstrgt()' unless @_ == 1;
#
# my $cmp = $self -> bstrcmp(shift);
# return defined($cmp) && $cmp > 0;
#}
#
#sub bstrge {
# my $self = shift;
# my $selfref = ref $self;
# my $class = $selfref || $self;
#
# croak 'bstrge() is an instance method, not a class method'
# unless $selfref;
# croak 'Wrong number of arguments for bstrge()' unless @_ == 1;
#
# my $cmp = $self -> bstrcmp(shift);
# return defined($cmp) && $cmp >= 0;
#}
sub badd {
# add second arg (BINT or string) to first (BINT) (modifies first)
# return result as BINT
# set up parameters
my ($class, $x, $y, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (ref($_[0]), @_)
: objectify(2, @_);
return $x if $x->modify('badd');
$r[3] = $y; # no push!
return $upgrade->badd($x, $y, @r)
if defined($upgrade) && (!$x->isa(__PACKAGE__) || !$y->isa(__PACKAGE__));
# Inf and NaN handling
if ($x->{sign} !~ /^[+-]$/ || $y->{sign} !~ /^[+-]$/) {
# NaN first
return $x->bnan(@r) if (($x->{sign} eq $nan) || ($y->{sign} eq $nan));
# Inf handling
if (($x->{sign} =~ /^[+-]inf$/) && ($y->{sign} =~ /^[+-]inf$/)) {
# +Inf + +Inf or -Inf + -Inf => same, rest is NaN
return $x->round(@r) if $x->{sign} eq $y->{sign};
return $x->bnan(@r);
}
# ±Inf + something => ±Inf
# something + ±Inf => ±Inf
if ($y->{sign} =~ /^[+-]inf$/) {
$x->{sign} = $y->{sign};
}
return $x -> round(@r);
}
($x->{value}, $x->{sign})
= $LIB -> _sadd($x->{value}, $x->{sign}, $y->{value}, $y->{sign});
$x->round(@r);
}
sub bsub {
# (BINT or num_str, BINT or num_str) return BINT
# subtract second arg from first, modify first
# set up parameters
my ($class, $x, $y, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (ref($_[0]), @_)
: objectify(2, @_);
return $x if $x -> modify('bsub');
return $upgrade -> bsub($x, $y, @r)
if defined($upgrade) && (!$x->isa(__PACKAGE__) || !$y->isa(__PACKAGE__));
return $x -> round(@r) if $y -> is_zero();
# To correctly handle the lone special case $x -> bsub($x), we note the
# sign of $x, then flip the sign from $y, and if the sign of $x did change,
# too, then we caught the special case:
my $xsign = $x -> {sign};
$y -> {sign} =~ tr/+-/-+/; # does nothing for NaN
if ($xsign ne $x -> {sign}) {
# special case of $x -> bsub($x) results in 0
return $x -> bzero(@r) if $xsign =~ /^[+-]$/;
return $x -> bnan(@r); # NaN, -inf, +inf
}
$x = $x -> badd($y, @r); # badd() does not leave internal zeros
$y -> {sign} =~ tr/+-/-+/; # refix $y (does nothing for NaN)
$x; # already rounded by badd() or no rounding
}
sub bmul {
# multiply the first number by the second number
# (BINT or num_str, BINT or num_str) return BINT
# set up parameters
my ($class, $x, $y, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (ref($_[0]), @_)
: objectify(2, @_);
return $x if $x->modify('bmul');
return $x->bnan(@r) if (($x->{sign} eq $nan) || ($y->{sign} eq $nan));
# inf handling
if (($x->{sign} =~ /^[+-]inf$/) || ($y->{sign} =~ /^[+-]inf$/)) {
return $x->bnan(@r) if $x->is_zero() || $y->is_zero();
# result will always be +-inf:
# +inf * +/+inf => +inf, -inf * -/-inf => +inf
# +inf * -/-inf => -inf, -inf * +/+inf => -inf
return $x->binf(@r) if ($x->{sign} =~ /^\+/ && $y->{sign} =~ /^\+/);
return $x->binf(@r) if ($x->{sign} =~ /^-/ && $y->{sign} =~ /^-/);
return $x->binf('-', @r);
}
return $upgrade->bmul($x, $y, @r)
if defined($upgrade) && (!$x->isa(__PACKAGE__) || !$y->isa(__PACKAGE__));
$r[3] = $y; # no push here
$x->{sign} = $x->{sign} eq $y->{sign} ? '+' : '-'; # +1 * +1 or -1 * -1 => +
$x->{value} = $LIB->_mul($x->{value}, $y->{value}); # do actual math
$x->{sign} = '+' if $LIB->_is_zero($x->{value}); # no -0
$x->round(@r);
}
sub bmuladd {
# multiply two numbers and then add the third to the result
# (BINT or num_str, BINT or num_str, BINT or num_str) return BINT
# set up parameters
my ($class, $x, $y, $z, @r)
= ref($_[0]) && ref($_[0]) eq ref($_[1]) && ref($_[1]) eq ref($_[2])
? (ref($_[0]), @_)
: objectify(3, @_);
return $x if $x->modify('bmuladd');
# x, y, and z are finite numbers
if ($x->{sign} =~ /^[+-]$/ &&
$y->{sign} =~ /^[+-]$/ &&
$z->{sign} =~ /^[+-]$/)
{
return $upgrade->bmuladd($x, $y, $z, @r)
if defined($upgrade) && (!$x->isa(__PACKAGE__) ||
!$y->isa(__PACKAGE__) ||
!$z->isa(__PACKAGE__));
# TODO: what if $y and $z have A or P set?
$r[3] = $z; # no push here
my $zs = $z->{sign};
my $zv = $z->{value};
$zv = $LIB -> _copy($zv) if refaddr($x) eq refaddr($z);
$x->{sign} = $x->{sign} eq $y->{sign} ? '+' : '-'; # +1 * +1 or -1 * -1 => +
$x->{value} = $LIB->_mul($x->{value}, $y->{value}); # do actual math
$x->{sign} = '+' if $LIB->_is_zero($x->{value}); # no -0
($x->{value}, $x->{sign})
= $LIB -> _sadd($x->{value}, $x->{sign}, $zv, $zs);
return $x->round(@r);
}
# At least one of x, y, and z is a NaN
return $x->bnan(@r) if (($x->{sign} eq $nan) ||
($y->{sign} eq $nan) ||
($z->{sign} eq $nan));
# At least one of x, y, and z is an Inf
if ($x->{sign} eq "-inf") {
if ($y -> is_neg()) { # x = -inf, y < 0
if ($z->{sign} eq "-inf") {
return $x->bnan(@r);
} else {
return $x->binf("+", @r);
}
} elsif ($y -> is_zero()) { # x = -inf, y = 0
return $x->bnan(@r);
} else { # x = -inf, y > 0
if ($z->{sign} eq "+inf") {
return $x->bnan(@r);
} else {
return $x->binf("-", @r);
}
}
} elsif ($x->{sign} eq "+inf") {
if ($y -> is_neg()) { # x = +inf, y < 0
if ($z->{sign} eq "+inf") {
return $x->bnan(@r);
} else {
return $x->binf("-", @r);
}
} elsif ($y -> is_zero()) { # x = +inf, y = 0
return $x->bnan(@r);
} else { # x = +inf, y > 0
if ($z->{sign} eq "-inf") {
return $x->bnan(@r);
} else {
return $x->binf("+", @r);
}
}
} elsif ($x -> is_neg()) {
if ($y->{sign} eq "-inf") { # -inf < x < 0, y = -inf
if ($z->{sign} eq "-inf") {
return $x->bnan(@r);
} else {
return $x->binf("+", @r);
}
} elsif ($y->{sign} eq "+inf") { # -inf < x < 0, y = +inf
if ($z->{sign} eq "+inf") {
return $x->bnan(@r);
} else {
return $x->binf("-", @r);
}
} else { # -inf < x < 0, -inf < y < +inf
if ($z->{sign} eq "-inf") {
return $x->binf("-", @r);
} elsif ($z->{sign} eq "+inf") {
return $x->binf("+", @r);
}
}
} elsif ($x -> is_zero()) {
if ($y->{sign} eq "-inf") { # x = 0, y = -inf
return $x->bnan(@r);
} elsif ($y->{sign} eq "+inf") { # x = 0, y = +inf
return $x->bnan(@r);
} else { # x = 0, -inf < y < +inf
if ($z->{sign} eq "-inf") {
return $x->binf("-", @r);
} elsif ($z->{sign} eq "+inf") {
return $x->binf("+", @r);
}
}
} elsif ($x -> is_pos()) {
if ($y->{sign} eq "-inf") { # 0 < x < +inf, y = -inf
if ($z->{sign} eq "+inf") {
return $x->bnan(@r);
} else {
return $x->binf("-", @r);
}
} elsif ($y->{sign} eq "+inf") { # 0 < x < +inf, y = +inf
if ($z->{sign} eq "-inf") {
return $x->bnan(@r);
} else {
return $x->binf("+", @r);
}
} else { # 0 < x < +inf, -inf < y < +inf
if ($z->{sign} eq "-inf") {
return $x->binf("-", @r);
} elsif ($z->{sign} eq "+inf") {
return $x->binf("+", @r);
}
}
}
die;
}
sub bdiv {
# This does floored division, where the quotient is floored, i.e., rounded
# towards negative infinity. As a consequence, the remainder has the same
# sign as the divisor.
# Set up parameters.
my ($class, $x, $y, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (ref($_[0]), @_)
: objectify(2, @_);
return $x if $x -> modify('bdiv');
my $wantarray = wantarray; # call only once
# At least one argument is NaN. Return NaN for both quotient and the
# modulo/remainder.
if ($x -> is_nan() || $y -> is_nan()) {
return $wantarray ? ($x -> bnan(@r), $class -> bnan(@r))
: $x -> bnan(@r);
}
# Divide by zero and modulo zero.
#
# Division: Use the common convention that x / 0 is inf with the same sign
# as x, except when x = 0, where we return NaN. This is also what earlier
# versions did.
#
# Modulo: In modular arithmetic, the congruence relation z = x (mod y)
# means that there is some integer k such that z - x = k y. If y = 0, we
# get z - x = 0 or z = x. This is also what earlier versions did, except
# that 0 % 0 returned NaN.
#
# inf / 0 = inf inf % 0 = inf
# 5 / 0 = inf 5 % 0 = 5
# 0 / 0 = NaN 0 % 0 = 0
# -5 / 0 = -inf -5 % 0 = -5
# -inf / 0 = -inf -inf % 0 = -inf
if ($y -> is_zero()) {
my $rem;
if ($wantarray) {
$rem = $x -> copy() -> round(@r);
}
if ($x -> is_zero()) {
$x = $x -> bnan(@r);
} else {
$x = $x -> binf($x -> {sign}, @r);
}
return $wantarray ? ($x, $rem) : $x;
}
# Numerator (dividend) is +/-inf, and denominator is finite and non-zero.
# The divide by zero cases are covered above. In all of the cases listed
# below we return the same as core Perl.
#
# inf / -inf = NaN inf % -inf = NaN
# inf / -5 = -inf inf % -5 = NaN
# inf / 5 = inf inf % 5 = NaN
# inf / inf = NaN inf % inf = NaN
#
# -inf / -inf = NaN -inf % -inf = NaN
# -inf / -5 = inf -inf % -5 = NaN
# -inf / 5 = -inf -inf % 5 = NaN
# -inf / inf = NaN -inf % inf = NaN
if ($x -> is_inf()) {
my $rem;
$rem = $class -> bnan(@r) if $wantarray;
if ($y -> is_inf()) {
$x = $x -> bnan(@r);
} else {
my $sign = $x -> bcmp(0) == $y -> bcmp(0) ? '+' : '-';
$x = $x -> binf($sign, @r);
}
return $wantarray ? ($x, $rem) : $x;
}
# Denominator (divisor) is +/-inf. The cases when the numerator is +/-inf
# are covered above. In the modulo cases (in the right column) we return
# the same as core Perl, which does floored division, so for consistency we
# also do floored division in the division cases (in the left column).
#
# -5 / inf = -1 -5 % inf = inf
# 0 / inf = 0 0 % inf = 0
# 5 / inf = 0 5 % inf = 5
#
# -5 / -inf = 0 -5 % -inf = -5
# 0 / -inf = 0 0 % -inf = 0
# 5 / -inf = -1 5 % -inf = -inf
if ($y -> is_inf()) {
my $rem;
if ($x -> is_zero() || $x -> bcmp(0) == $y -> bcmp(0)) {
$rem = $x -> copy() -> round(@r) if $wantarray;
$x = $x -> bzero(@r);
} else {
$rem = $class -> binf($y -> {sign}, @r) if $wantarray;
$x = $x -> bone('-', @r);
}
return $wantarray ? ($x, $rem) : $x;
}
# At this point, both the numerator and denominator are finite numbers, and
# the denominator (divisor) is non-zero.
# Division might return a non-integer result, so upgrade unconditionally, if
# upgrading is enabled.
return $upgrade -> bdiv($x, $y, @r) if defined $upgrade;
$r[3] = $y; # no push!
# Inialize remainder.
my $rem = $class -> bzero();
# Are both operands the same object, i.e., like $x -> bdiv($x)? If so,
# flipping the sign of $y also flips the sign of $x.
my $xsign = $x -> {sign};
my $ysign = $y -> {sign};
$y -> {sign} =~ tr/+-/-+/; # Flip the sign of $y, and see ...
my $same = $xsign ne $x -> {sign}; # ... if that changed the sign of $x.
$y -> {sign} = $ysign; # Re-insert the original sign.
if ($same) {
$x = $x -> bone();
} else {
($x -> {value}, $rem -> {value}) =
$LIB -> _div($x -> {value}, $y -> {value});
if ($LIB -> _is_zero($rem -> {value})) {
if ($xsign eq $ysign || $LIB -> _is_zero($x -> {value})) {
$x -> {sign} = '+';
} else {
$x -> {sign} = '-';
}
} else {
if ($xsign eq $ysign) {
$x -> {sign} = '+';
} else {
if ($xsign eq '+') {
$x = $x -> badd(1);
} else {
$x = $x -> bsub(1);
}
$x -> {sign} = '-';
}
}
}
$x = $x -> round(@r);
if ($wantarray) {
unless ($LIB -> _is_zero($rem -> {value})) {
if ($xsign ne $ysign) {
$rem = $y -> copy() -> babs() -> bsub($rem);
}
$rem -> {sign} = $ysign;
}
$rem -> {accuracy} = $x -> {accuracy};
$rem -> {precision} = $x -> {precision};
$rem = $rem -> round(@r);
return ($x, $rem);
}
return $x;
}
sub btdiv {
# This does truncated division, where the quotient is truncted, i.e.,
# rounded towards zero.
#
# ($q, $r) = $x -> btdiv($y) returns $q and $r so that $q is int($x / $y)
# and $q * $y + $r = $x.
# Set up parameters
my ($class, $x, $y, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (ref($_[0]), @_)
: objectify(2, @_);
return $x if $x -> modify('btdiv');
my $wantarray = wantarray; # call only once
# At least one argument is NaN. Return NaN for both quotient and the
# modulo/remainder.
if ($x -> is_nan() || $y -> is_nan()) {
return $wantarray ? ($x -> bnan(@r), $class -> bnan(@r))
: $x -> bnan(@r);
}
# Divide by zero and modulo zero.
#
# Division: Use the common convention that x / 0 is inf with the same sign
# as x, except when x = 0, where we return NaN. This is also what earlier
# versions did.
#
# Modulo: In modular arithmetic, the congruence relation z = x (mod y)
# means that there is some integer k such that z - x = k y. If y = 0, we
# get z - x = 0 or z = x. This is also what earlier versions did, except
# that 0 % 0 returned NaN.
#
# inf / 0 = inf inf % 0 = inf
# 5 / 0 = inf 5 % 0 = 5
# 0 / 0 = NaN 0 % 0 = 0
# -5 / 0 = -inf -5 % 0 = -5
# -inf / 0 = -inf -inf % 0 = -inf
if ($y -> is_zero()) {
my $rem;
if ($wantarray) {
$rem = $x -> copy(@r);
}
if ($x -> is_zero()) {
$x = $x -> bnan(@r);
} else {
$x = $x -> binf($x -> {sign}, @r);
}
return $wantarray ? ($x, $rem) : $x;
}
# Numerator (dividend) is +/-inf, and denominator is finite and non-zero.
# The divide by zero cases are covered above. In all of the cases listed
# below we return the same as core Perl.
#
# inf / -inf = NaN inf % -inf = NaN
# inf / -5 = -inf inf % -5 = NaN
# inf / 5 = inf inf % 5 = NaN
# inf / inf = NaN inf % inf = NaN
#
# -inf / -inf = NaN -inf % -inf = NaN
# -inf / -5 = inf -inf % -5 = NaN
# -inf / 5 = -inf -inf % 5 = NaN
# -inf / inf = NaN -inf % inf = NaN
if ($x -> is_inf()) {
my $rem;
$rem = $class -> bnan(@r) if $wantarray;
if ($y -> is_inf()) {
$x = $x -> bnan(@r);
} else {
my $sign = $x -> bcmp(0) == $y -> bcmp(0) ? '+' : '-';
$x = $x -> binf($sign,@r );
}
return $wantarray ? ($x, $rem) : $x;
}
# Denominator (divisor) is +/-inf. The cases when the numerator is +/-inf
# are covered above. In the modulo cases (in the right column) we return
# the same as core Perl, which does floored division, so for consistency we
# also do floored division in the division cases (in the left column).
#
# -5 / inf = 0 -5 % inf = -5
# 0 / inf = 0 0 % inf = 0
# 5 / inf = 0 5 % inf = 5
#
# -5 / -inf = 0 -5 % -inf = -5
# 0 / -inf = 0 0 % -inf = 0
# 5 / -inf = 0 5 % -inf = 5
if ($y -> is_inf()) {
my $rem;
$rem = $x -> copy() -> round(@r) if $wantarray;
$x = $x -> bzero(@r);
return $wantarray ? ($x, $rem) : $x;
}
# Division might return a non-integer result, so upgrade unconditionally, if
# upgrading is enabled.
return $upgrade -> btdiv($x, $y, @r) if defined $upgrade;
$r[3] = $y; # no push!
# Inialize remainder.
my $rem = $class -> bzero();
# Are both operands the same object, i.e., like $x -> bdiv($x)? If so,
# flipping the sign of $y also flips the sign of $x.
my $xsign = $x -> {sign};
my $ysign = $y -> {sign};
$y -> {sign} =~ tr/+-/-+/; # Flip the sign of $y, and see ...
my $same = $xsign ne $x -> {sign}; # ... if that changed the sign of $x.
$y -> {sign} = $ysign; # Re-insert the original sign.
if ($same) {
$x = $x -> bone(@r);
} else {
($x -> {value}, $rem -> {value}) =
$LIB -> _div($x -> {value}, $y -> {value});
$x -> {sign} = $xsign eq $ysign ? '+' : '-';
$x -> {sign} = '+' if $LIB -> _is_zero($x -> {value});
$x = $x -> round(@r);
}
if (wantarray) {
$rem -> {sign} = $xsign;
$rem -> {sign} = '+' if $LIB -> _is_zero($rem -> {value});
$rem -> {accuracy} = $x -> {accuracy};
$rem -> {precision} = $x -> {precision};
$rem = $rem -> round(@r);
return ($x, $rem);
}
return $x;
}
sub bmod {
# This is the remainder after floored division.
# Set up parameters.
my ($class, $x, $y, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (ref($_[0]), @_)
: objectify(2, @_);
return $x if $x -> modify('bmod');
$r[3] = $y; # no push!
# At least one argument is NaN.
if ($x -> is_nan() || $y -> is_nan()) {
return $x -> bnan(@r);
}
# Modulo zero. See documentation for bdiv().
if ($y -> is_zero()) {
return $x -> round(@r);
}
# Numerator (dividend) is +/-inf.
if ($x -> is_inf()) {
return $x -> bnan(@r);
}
# Denominator (divisor) is +/-inf.
if ($y -> is_inf()) {
if ($x -> is_zero() || $x -> bcmp(0) == $y -> bcmp(0)) {
return $x -> round(@r);
} else {
return $x -> binf($y -> sign(), @r);
}
}
return $upgrade -> bmod($x, $y, @r)
if defined($upgrade) && (!$x -> isa(__PACKAGE__) ||
!$y -> isa(__PACKAGE__));
# Calc new sign and in case $y == +/- 1, return $x.
$x -> {value} = $LIB -> _mod($x -> {value}, $y -> {value});
if ($LIB -> _is_zero($x -> {value})) {
$x -> {sign} = '+'; # do not leave -0
} else {
$x -> {value} = $LIB -> _sub($y -> {value}, $x -> {value}, 1) # $y-$x
if ($x -> {sign} ne $y -> {sign});
$x -> {sign} = $y -> {sign};
}
$x -> round(@r);
}
sub btmod {
# Remainder after truncated division.
# set up parameters
my ($class, $x, $y, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (ref($_[0]), @_)
: objectify(2, @_);
return $x if $x -> modify('btmod');
# At least one argument is NaN.
if ($x -> is_nan() || $y -> is_nan()) {
return $x -> bnan(@r);
}
# Modulo zero. See documentation for btdiv().
if ($y -> is_zero()) {
return $x -> round(@r);
}
# Numerator (dividend) is +/-inf.
if ($x -> is_inf()) {
return $x -> bnan(@r);
}
# Denominator (divisor) is +/-inf.
if ($y -> is_inf()) {
return $x -> round(@r);
}
return $upgrade -> btmod($x, $y, @r)
if defined($upgrade) && (!$x -> isa(__PACKAGE__) ||
!$y -> isa(__PACKAGE__));
$r[3] = $y; # no push!
my $xsign = $x -> {sign};
$x -> {value} = $LIB -> _mod($x -> {value}, $y -> {value});
$x -> {sign} = $xsign;
$x -> {sign} = '+' if $LIB -> _is_zero($x -> {value});
$x -> round(@r);
}
sub bmodinv {
# Return modular multiplicative inverse:
#
# z is the modular inverse of x (mod y) if and only if
#
# x*z ≡ 1 (mod y)
#
# If the modulus y is larger than one, x and z are relative primes (i.e.,
# their greatest common divisor is one).
#
# If no modular multiplicative inverse exists, NaN is returned.
# set up parameters
my ($class, $x, $y, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (ref($_[0]), @_)
: objectify(2, @_);
return $x if $x->modify('bmodinv');
# Return NaN if one or both arguments is +inf, -inf, or nan.
return $x->bnan(@r) if ($y->{sign} !~ /^[+-]$/ ||
$x->{sign} !~ /^[+-]$/);
# Return NaN if $y is zero; 1 % 0 makes no sense.
return $x->bnan(@r) if $y->is_zero();
# Return 0 in the trivial case. $x % 1 or $x % -1 is zero for all finite
# integers $x.
return $x->bzero(@r) if ($y->is_one('+') ||
$y->is_one('-'));
return $upgrade -> bmodinv($x, $y, @r)
if defined($upgrade) && (!$x -> isa(__PACKAGE__) ||
!$y -> isa(__PACKAGE__));
# Return NaN if $x = 0, or $x modulo $y is zero. The only valid case when
# $x = 0 is when $y = 1 or $y = -1, but that was covered above.
#
# Note that computing $x modulo $y here affects the value we'll feed to
# $LIB->_modinv() below when $x and $y have opposite signs. E.g., if $x =
# 5 and $y = 7, those two values are fed to _modinv(), but if $x = -5 and
# $y = 7, the values fed to _modinv() are $x = 2 (= -5 % 7) and $y = 7.
# The value if $x is affected only when $x and $y have opposite signs.
$x = $x->bmod($y);
return $x->bnan(@r) if $x->is_zero();
# Compute the modular multiplicative inverse of the absolute values. We'll
# correct for the signs of $x and $y later. Return NaN if no GCD is found.
($x->{value}, $x->{sign}) = $LIB->_modinv($x->{value}, $y->{value});
return $x->bnan(@r) if !defined($x->{value});
# Library inconsistency workaround: _modinv() in Math::BigInt::GMP versions
# <= 1.32 return undef rather than a "+" for the sign.
$x->{sign} = '+' unless defined $x->{sign};
# When one or both arguments are negative, we have the following
# relations. If x and y are positive:
#
# modinv(-x, -y) = -modinv(x, y)
# modinv(-x, y) = y - modinv(x, y) = -modinv(x, y) (mod y)
# modinv( x, -y) = modinv(x, y) - y = modinv(x, y) (mod -y)
# We must swap the sign of the result if the original $x is negative.
# However, we must compensate for ignoring the signs when computing the
# inverse modulo. The net effect is that we must swap the sign of the
# result if $y is negative.
$x = $x -> bneg() if $y->{sign} eq '-';
# Compute $x modulo $y again after correcting the sign.
$x = $x -> bmod($y) if $x->{sign} ne $y->{sign};
$x -> round(@r);
}
sub bmodpow {
# Modular exponentiation. Raises a very large number to a very large
# exponent in a given very large modulus quickly, thanks to binary
# exponentiation. Supports negative exponents.
my ($class, $num, $exp, $mod, @r)
= ref($_[0]) && ref($_[0]) eq ref($_[1]) && ref($_[1]) eq ref($_[2])
? (ref($_[0]), @_)
: objectify(3, @_);
return $num if $num->modify('bmodpow');
# When the exponent 'e' is negative, use the following relation, which is
# based on finding the multiplicative inverse 'd' of 'b' modulo 'm':
#
# b^(-e) (mod m) = d^e (mod m) where b*d = 1 (mod m)
$num = $num -> bmodinv($mod) if ($exp->{sign} eq '-');
# Check for valid input. All operands must be finite, and the modulus must
# be non-zero.
return $num->bnan(@r) if ($num->{sign} =~ /NaN|inf/ || # NaN, -inf, +inf
$exp->{sign} =~ /NaN|inf/ || # NaN, -inf, +inf
$mod->{sign} =~ /NaN|inf/); # NaN, -inf, +inf
# Modulo zero. See documentation for Math::BigInt's bmod() method.
if ($mod -> is_zero()) {
if ($num -> is_zero()) {
return $class -> bnan(@r);
} else {
return $num -> copy(@r);
}
}
return $upgrade -> bmodinv($num, $exp, $mod, @r)
if defined($upgrade) && (!$num -> isa(__PACKAGE__) ||
!$exp -> isa(__PACKAGE__) ||
!$mod -> ($class));
# Compute 'a (mod m)', ignoring the signs on 'a' and 'm'. If the resulting
# value is zero, the output is also zero, regardless of the signs on 'a' and
# 'm'.
my $value = $LIB->_modpow($num->{value}, $exp->{value}, $mod->{value});
my $sign = '+';
# If the resulting value is non-zero, we have four special cases, depending
# on the signs on 'a' and 'm'.
unless ($LIB->_is_zero($value)) {
# There is a negative sign on 'a' (= $num**$exp) only if the number we
# are exponentiating ($num) is negative and the exponent ($exp) is odd.
if ($num->{sign} eq '-' && $exp->is_odd()) {
# When both the number 'a' and the modulus 'm' have a negative sign,
# use this relation:
#
# -a (mod -m) = -(a (mod m))
if ($mod->{sign} eq '-') {
$sign = '-';
}
# When only the number 'a' has a negative sign, use this relation:
#
# -a (mod m) = m - (a (mod m))
else {
# Use copy of $mod since _sub() modifies the first argument.
my $mod = $LIB->_copy($mod->{value});
$value = $LIB->_sub($mod, $value);
$sign = '+';
}
} else {
# When only the modulus 'm' has a negative sign, use this relation:
#
# a (mod -m) = (a (mod m)) - m
# = -(m - (a (mod m)))
if ($mod->{sign} eq '-') {
# Use copy of $mod since _sub() modifies the first argument.
my $mod = $LIB->_copy($mod->{value});
$value = $LIB->_sub($mod, $value);
$sign = '-';
}
# When neither the number 'a' nor the modulus 'm' have a negative
# sign, directly return the already computed value.
#
# (a (mod m))
}
}
$num->{value} = $value;
$num->{sign} = $sign;
return $num -> round(@r);
}
sub bpow {
# (BINT or num_str, BINT or num_str) return BINT
# compute power of two numbers -- stolen from Knuth Vol 2 pg 233
# modifies first argument
# set up parameters
my ($class, $x, $y, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (ref($_[0]), @_)
: objectify(2, @_);
return $x if $x -> modify('bpow');
# $x and/or $y is a NaN
return $x -> bnan(@r) if $x -> is_nan() || $y -> is_nan();
# $x and/or $y is a +/-Inf
if ($x -> is_inf("-")) {
return $x -> bzero(@r) if $y -> is_negative();
return $x -> bnan(@r) if $y -> is_zero();
return $x -> round(@r) if $y -> is_odd();
return $x -> bneg(@r);
} elsif ($x -> is_inf("+")) {
return $x -> bzero(@r) if $y -> is_negative();
return $x -> bnan(@r) if $y -> is_zero();
return $x -> round(@r);
} elsif ($y -> is_inf("-")) {
return $x -> bnan(@r) if $x -> is_one("-");
return $x -> binf("+", @r) if $x -> is_zero();
return $x -> bone(@r) if $x -> is_one("+");
return $x -> bzero(@r);
} elsif ($y -> is_inf("+")) {
return $x -> bnan(@r) if $x -> is_one("-");
return $x -> bzero(@r) if $x -> is_zero();
return $x -> bone(@r) if $x -> is_one("+");
return $x -> binf("+", @r);
}
if ($x -> is_zero()) {
return $x -> bone(@r) if $y -> is_zero();
return $x -> binf(@r) if $y -> is_negative();
return $x -> round(@r);
}
if ($x -> is_one("+")) {
return $x -> round(@r);
}
if ($x -> is_one("-")) {
return $x -> round(@r) if $y -> is_odd();
return $x -> bneg(@r);
}
return $upgrade -> bpow($x, $y, @r) if defined $upgrade;
# We don't support finite non-integers, so return zero. The reason for
# returning zero, not NaN, is that all output is in the open interval (0,1),
# and truncating that to integer gives zero.
if ($y->{sign} eq '-' || !$y -> isa(__PACKAGE__)) {
return $x -> bzero(@r);
}
$r[3] = $y; # no push!
$x->{value} = $LIB -> _pow($x->{value}, $y->{value});
$x->{sign} = $x -> is_negative() && $y -> is_odd() ? '-' : '+';
$x -> round(@r);
}
sub binv {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), $_[0]) : objectify(1, @_);
return $x if $x -> modify('binv');
return $x -> binf("+", @r) if $x -> is_zero();
return $x -> bzero(@r) if $x -> is_inf();
return $x -> bnan(@r) if $x -> is_nan();
return $x -> round(@r) if $x -> is_one("+") || $x -> is_one("-");
return $upgrade -> binv($x, @r) if defined $upgrade;
$x -> bzero(@r);
}
sub blog {
# Return the logarithm of the operand. If a second operand is defined, that
# value is used as the base, otherwise the base is assumed to be Euler's
# constant.
my ($class, $x, $base, @r);
# Only objectify the base if it is defined, since an undefined base, as in
# $x->blog() or $x->blog(undef) signals that the base is Euler's number =
# 2.718281828...
if (!ref($_[0]) && $_[0] =~ /^[a-z]\w*(?:::\w+)*$/i) {
# E.g., Math::BigInt->blog(256, 2)
($class, $x, $base, @r) =
defined $_[2] ? objectify(2, @_) : objectify(1, @_);
} else {
# E.g., $x->blog(2) or the deprecated Math::BigInt::blog(256, 2)
($class, $x, $base, @r) =
defined $_[1] ? objectify(2, @_) : objectify(1, @_);
}
return $x if $x->modify('blog');
# Handle all exception cases and all trivial cases. I have used Wolfram
# Alpha (http://www.wolframalpha.com) as the reference for these cases.
return $x -> bnan(@r) if $x -> is_nan();
if (defined $base) {
$base = $class -> new($base)
unless defined(blessed($base)) && $base -> isa(__PACKAGE__);
if ($base -> is_nan() || $base -> is_one()) {
return $x -> bnan(@r);
} elsif ($base -> is_inf() || $base -> is_zero()) {
return $x -> bnan(@r) if $x -> is_inf() || $x -> is_zero();
return $x -> bzero(@r);
} elsif ($base -> is_negative()) { # -inf < base < 0
return $x -> bzero(@r) if $x -> is_one(); # x = 1
return $x -> bone('+', @r) if $x == $base; # x = base
# we can't handle these cases, so upgrade, if we can
return $upgrade -> blog($x, $base, @r) if defined $upgrade;
return $x -> bnan(@r);
}
return $x -> bone(@r) if $x == $base; # 0 < base && 0 < x < inf
}
# We now know that the base is either undefined or >= 2 and finite.
if ($x -> is_inf()) { # x = +/-inf
return $x -> binf('+', @r);
} elsif ($x -> is_neg()) { # -inf < x < 0
return $upgrade -> blog($x, $base, @r) if defined $upgrade;
return $x -> bnan(@r);
} elsif ($x -> is_one()) { # x = 1
return $x -> bzero(@r);
} elsif ($x -> is_zero()) { # x = 0
return $x -> binf('-', @r);
}
# At this point we are done handling all exception cases and trivial cases.
return $upgrade -> blog($x, $base, @r) if defined $upgrade;
# fix for bug #24969:
# the default base is e (Euler's number) which is not an integer
if (!defined $base) {
require Math::BigFloat;
# disable upgrading and downgrading
my $upg = Math::BigFloat -> upgrade();
my $dng = Math::BigFloat -> downgrade();
Math::BigFloat -> upgrade(undef);
Math::BigFloat -> downgrade(undef);
my $u = Math::BigFloat -> blog($x) -> as_int();
# reset upgrading and downgrading
Math::BigFloat -> upgrade($upg);
Math::BigFloat -> downgrade($dng);
# modify $x in place
$x->{value} = $u->{value};
$x->{sign} = $u->{sign};
return $x -> round(@r);
}
my ($rc) = $LIB -> _log_int($x->{value}, $base->{value});
return $x -> bnan(@r) unless defined $rc; # not possible to take log?
$x->{value} = $rc;
$x = $x -> round(@r);
}
sub bexp {
# Calculate e ** $x (Euler's number to the power of X), truncated to
# an integer value.
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
return $x if $x->modify('bexp');
# inf, -inf, NaN, <0 => NaN
return $x -> bnan(@r) if $x->{sign} eq 'NaN';
return $x -> bone(@r) if $x->is_zero();
return $x -> round(@r) if $x->{sign} eq '+inf';
return $x -> bzero(@r) if $x->{sign} eq '-inf';
return $upgrade -> bexp($x, @r) if defined $upgrade;
require Math::BigFloat;
my $tmp = Math::BigFloat -> bexp($x, @r) -> as_int();
$x->{value} = $tmp->{value};
return $x -> round(@r);
}
sub bilog2 {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
return $x if $x -> modify('bilog2');
return $upgrade -> new($x, @r) unless $x -> isa(__PACKAGE__);
return $x -> bnan(@r) if $x -> is_nan();
return $x -> binf("+", @r) if $x -> is_inf("+");
return $x -> binf("-", @r) if $x -> is_zero();
if ($x -> is_neg()) {
return $upgrade -> bilog2($x, @r) if $upgrade;
return $x -> bnan(@r);
}
$x -> {value} = $LIB -> _ilog2($x -> {value});
return $x -> round(@r);
}
sub bilog10 {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
return $x if $x -> modify('bilog10');
return $upgrade -> new($x, @r) unless $x -> isa(__PACKAGE__);
return $x -> bnan(@r) if $x -> is_nan();
return $x -> binf("+", @r) if $x -> is_inf("+");
return $x -> binf("-", @r) if $x -> is_zero();
if ($x -> is_neg()) {
return $upgrade -> bilog2($x, @r) if $upgrade;
return $x -> bnan(@r);
}
$x -> {value} = $LIB -> _ilog10($x -> {value});
return $x -> round(@r);
}
sub bclog2 {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
return $x if $x -> modify('bclog2');
return $upgrade -> new($x, @r) unless $x -> isa(__PACKAGE__);
return $x -> bnan(@r) if $x -> is_nan();
return $x -> binf("+", @r) if $x -> is_inf("+");
return $x -> binf("-", @r) if $x -> is_zero();
if ($x -> is_neg()) {
return $upgrade -> bilog2($x, @r) if $upgrade;
return $x -> bnan(@r);
}
$x -> {value} = $LIB -> _clog2($x -> {value});
return $x -> round(@r);
}
sub bclog10 {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
return $x if $x -> modify('bclog10');
return $upgrade -> new($x, @r) unless $x -> isa(__PACKAGE__);
return $x -> bnan(@r) if $x -> is_nan();
return $x -> binf("+", @r) if $x -> is_inf("+");
return $x -> binf("-", @r) if $x -> is_zero();
if ($x -> is_neg()) {
return $upgrade -> bilog2($x, @r) if $upgrade;
return $x -> bnan(@r);
}
$x -> {value} = $LIB -> _clog10($x -> {value});
return $x -> round(@r);
}
sub bnok {
# Calculate n over k (binomial coefficient or "choose" function) as
# integer.
# Set up parameters.
my ($class, $n, $k, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (ref($_[0]), @_)
: objectify(2, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
return $n if $n->modify('bnok');
# All cases where at least one argument is NaN.
return $n->bnan(@r) if $n->{sign} eq 'NaN' || $k->{sign} eq 'NaN';
# All cases where at least one argument is +/-inf.
if ($n -> is_inf()) {
if ($k -> is_inf()) { # bnok(+/-inf,+/-inf)
return $n -> bnan(@r);
} elsif ($k -> is_neg()) { # bnok(+/-inf,k), k < 0
return $n -> bzero(@r);
} elsif ($k -> is_zero()) { # bnok(+/-inf,k), k = 0
return $n -> bone(@r);
} else {
if ($n -> is_inf("+", @r)) { # bnok(+inf,k), 0 < k < +inf
return $n -> binf("+");
} else { # bnok(-inf,k), k > 0
my $sign = $k -> is_even() ? "+" : "-";
return $n -> binf($sign, @r);
}
}
}
elsif ($k -> is_inf()) { # bnok(n,+/-inf), -inf <= n <= inf
return $n -> bnan(@r);
}
# At this point, both n and k are real numbers.
return $upgrade -> bnok($n, $k, @r)
if defined($upgrade) && (!$n -> isa(__PACKAGE__) ||
!$k -> isa(__PACKAGE__));
my $sign = 1;
if ($n >= 0) {
if ($k < 0 || $k > $n) {
return $n -> bzero(@r);
}
} else {
if ($k >= 0) {
# n < 0 and k >= 0: bnok(n,k) = (-1)^k * bnok(-n+k-1,k)
$sign = (-1) ** $k;
$n = $n -> bneg() -> badd($k) -> bdec();
} elsif ($k <= $n) {
# n < 0 and k <= n: bnok(n,k) = (-1)^(n-k) * bnok(-k-1,n-k)
$sign = (-1) ** ($n - $k);
my $x0 = $n -> copy();
$n = $n -> bone() -> badd($k) -> bneg();
$k = $k -> copy();
$k = $k -> bneg() -> badd($x0);
} else {
# n < 0 and n < k < 0:
return $n -> bzero(@r);
}
}
$n->{value} = $LIB->_nok($n->{value}, $k->{value});
$n = $n -> bneg() if $sign == -1;
$n -> round(@r);
}
sub buparrow {
my $a = shift;
my $y = $a -> uparrow(@_);
$a -> {value} = $y -> {value};
return $a;
}
sub uparrow {
# Knuth's up-arrow notation buparrow(a, n, b)
#
# The following is a simple, recursive implementation of the up-arrow
# notation, just to show the idea. Such implementations cause "Deep
# recursion on subroutine ..." warnings, so we use a faster, non-recursive
# algorithm below with @_ as a stack.
#
# sub buparrow {
# my ($a, $n, $b) = @_;
# return $a ** $b if $n == 1;
# return $a * $b if $n == 0;
# return 1 if $b == 0;
# return buparrow($a, $n - 1, buparrow($a, $n, $b - 1));
# }
my ($a, $b, $n) = @_;
my $class = ref $a;
croak("a must be non-negative") if $a < 0;
croak("n must be non-negative") if $n < 0;
croak("b must be non-negative") if $b < 0;
while (@_ >= 3) {
# return $a ** $b if $n == 1;
if ($_[-2] == 1) {
my ($a, $n, $b) = splice @_, -3;
push @_, $a ** $b;
next;
}
# return $a * $b if $n == 0;
if ($_[-2] == 0) {
my ($a, $n, $b) = splice @_, -3;
push @_, $a * $b;
next;
}
# return 1 if $b == 0;
if ($_[-1] == 0) {
splice @_, -3;
push @_, $class -> bone();
next;
}
# return buparrow($a, $n - 1, buparrow($a, $n, $b - 1));
my ($a, $n, $b) = splice @_, -3;
push @_, ($a, $n - 1,
$a, $n, $b - 1);
}
pop @_;
}
sub backermann {
my $m = shift;
my $y = $m -> ackermann(@_);
$m -> {value} = $y -> {value};
return $m;
}
sub ackermann {
# Ackermann's function ackermann(m, n)
#
# The following is a simple, recursive implementation of the ackermann
# function, just to show the idea. Such implementations cause "Deep
# recursion on subroutine ..." warnings, so we use a faster, non-recursive
# algorithm below with @_ as a stack.
#
# sub ackermann {
# my ($m, $n) = @_;
# return $n + 1 if $m == 0;
# return ackermann($m - 1, 1) if $m > 0 && $n == 0;
# return ackermann($m - 1, ackermann($m, $n - 1) if $m > 0 && $n > 0;
# }
my ($m, $n) = @_;
my $class = ref $m;
croak("m must be non-negative") if $m < 0;
croak("n must be non-negative") if $n < 0;
my $two = $class -> new("2");
my $three = $class -> new("3");
my $thirteen = $class -> new("13");
$n = pop;
$n = $class -> new($n) unless ref($n);
while (@_) {
my $m = pop;
if ($m > $three) {
push @_, (--$m) x $n;
while (--$m >= $three) {
push @_, $m;
}
$n = $thirteen;
} elsif ($m == $three) {
$n = $class -> bone() -> blsft($n + $three) -> bsub($three);
} elsif ($m == $two) {
$n = $n -> bmul($two) -> badd($three);
} elsif ($m >= 0) {
$n = $n -> badd($m) -> binc();
} else {
die "negative m!";
}
}
$n;
}
sub bsin {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
return $x if $x -> modify('bsin');
# Trivial cases.
return $x -> bzero(@r) if $x -> is_zero();
return $x -> bnan(@r) if $x -> is_inf() || $x -> is_nan();
if ($upgrade) {
my $xtmp = $upgrade -> bsin($x, @r);
if ($xtmp -> is_int()) {
$xtmp = $xtmp -> as_int();
%$x = %$xtmp;
} else {
%$x = %$xtmp;
bless $x, $upgrade;
}
return $x;
}
# When x is an integer, sin(x) truncated to an integer is always zero.
$x -> bzero(@r);
}
sub bcos {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
return $x if $x -> modify('bcos');
# Trivial cases.
return $x -> bone(@r) if $x -> is_zero();
return $x -> bnan(@r) if $x -> is_inf() || $x -> is_nan();
if ($upgrade) {
my $xtmp = $upgrade -> bcos($x, @r);
if ($xtmp -> is_int()) {
$xtmp = $xtmp -> as_int();
%$x = %$xtmp;
} else {
%$x = %$xtmp;
bless $x, $upgrade;
}
return $x;
}
# When x is a non-zero integer, cos(x) truncated to an integer is always
# zero.
$x -> bzero(@r);
}
sub batan {
# Calculate arctan(x) to N digits. Unless upgrading is in effect, returns
# the result truncated to an integer.
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
return $x if $x->modify('batan');
return $x -> bnan(@r) if $x -> is_nan();
return $x -> bzero(@r) if $x -> is_zero();
return $upgrade -> batan($x, @r) if defined $upgrade;
return $x -> bone("+", @r) if $x -> bgt("1");
return $x -> bone("-", @r) if $x -> blt("-1");
$x -> bzero(@r);
}
sub batan2 {
# calculate arcus tangens of ($y/$x)
my ($class, $y, $x, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (ref($_[0]), @_) : objectify(2, @_);
return $y if $y->modify('batan2');
return $y->bnan() if ($y->{sign} eq $nan) || ($x->{sign} eq $nan);
return $upgrade->batan2($y, $x, @r) if defined $upgrade;
# Y X
# != 0 -inf result is +- pi
if ($x->is_inf() || $y->is_inf()) {
if ($y->is_inf()) {
if ($x->{sign} eq '-inf') {
# calculate 3 pi/4 => 2.3.. => 2
$y = $y->bone(substr($y->{sign}, 0, 1));
$y = $y->bmul($class->new(2));
} elsif ($x->{sign} eq '+inf') {
# calculate pi/4 => 0.7 => 0
$y = $y->bzero();
} else {
# calculate pi/2 => 1.5 => 1
$y = $y->bone(substr($y->{sign}, 0, 1));
}
} else {
if ($x->{sign} eq '+inf') {
# calculate pi/4 => 0.7 => 0
$y = $y->bzero();
} else {
# PI => 3.1415.. => 3
$y = $y->bone(substr($y->{sign}, 0, 1));
$y = $y->bmul($class->new(3));
}
}
return $y;
}
require Math::BigFloat;
my $r = Math::BigFloat->new($y)
->batan2(Math::BigFloat->new($x), @r)
->as_int();
$x->{value} = $r->{value};
$x->{sign} = $r->{sign};
$x->round(@r);
}
sub bsqrt {
# calculate square root of $x
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
return $x if $x -> modify('bsqrt');
return $x -> bnan(@r) if $x -> is_nan();
return $x -> round(@r) if $x -> is_zero() || $x -> is_inf("+");
if ($upgrade) {
$x = $upgrade -> bsqrt($x, @r);
$x = $x -> as_int() if $x -> is_int();
return $x;
}
return $x -> bnan(@r) if $x -> is_neg();
$x->{value} = $LIB -> _sqrt($x->{value});
return $x -> round(@r);
}
sub broot {
# calculate $y'th root of $x
# set up parameters
my ($class, $x, $y, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (ref($_[0]), @_) : objectify(2, @_);
$y = $class->new(2) unless defined $y;
return $x if $x->modify('broot');
# NaN handling: $x ** 1/0, x or y NaN, or y inf/-inf or y == 0
return $x->bnan(@r) if $x->{sign} !~ /^\+/ || $y->is_zero() ||
$y->{sign} !~ /^\+$/;
return $x->round(@r)
if $x->is_zero() || $x->is_one() || $x->is_inf() || $y->is_one();
return $upgrade->broot($x, $y, @r) if defined $upgrade;
$x->{value} = $LIB->_root($x->{value}, $y->{value});
$x->round(@r);
}
sub bfac {
# (BINT or num_str, BINT or num_str) return BINT
# compute factorial number from $x, modify $x in place
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
return $x if $x->modify('bfac') || $x->{sign} eq '+inf'; # inf => inf
return $x->bnan(@r) if $x->{sign} ne '+'; # NaN, <0 => NaN
return $upgrade -> bfac($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
$x->{value} = $LIB->_fac($x->{value});
$x->round(@r);
}
sub bdfac {
# compute double factorial, modify $x in place
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
return $x if $x->modify('bdfac') || $x->{sign} eq '+inf'; # inf => inf
return $x->bnan(@r) if $x->is_nan() || $x <= -2;
return $x->bone(@r) if $x <= 1;
return $upgrade -> bdfac($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
croak("bdfac() requires a newer version of the $LIB library.")
unless $LIB->can('_dfac');
$x->{value} = $LIB->_dfac($x->{value});
$x->round(@r);
}
sub btfac {
# compute triple factorial, modify $x in place
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
return $x if $x->modify('btfac') || $x->{sign} eq '+inf'; # inf => inf
return $x->bnan(@r) if $x->is_nan();
return $upgrade -> btfac($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
my $k = $class -> new("3");
return $x->bnan(@r) if $x <= -$k;
my $one = $class -> bone();
return $x->bone(@r) if $x <= $one;
my $f = $x -> copy();
while ($f -> bsub($k) > $one) {
$x = $x -> bmul($f);
}
$x->round(@r);
}
sub bmfac {
# compute multi-factorial
my ($class, $x, $k, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (ref($_[0]), @_) : objectify(2, @_);
return $x if $x->modify('bmfac') || $x->{sign} eq '+inf';
return $x->bnan(@r) if $x->is_nan() || $k->is_nan() || $k < 1 || $x <= -$k;
return $upgrade -> bmfac($x, $k, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
my $one = $class -> bone();
return $x->bone(@r) if $x <= $one;
my $f = $x -> copy();
while ($f -> bsub($k) > $one) {
$x = $x -> bmul($f);
}
$x->round(@r);
}
sub bfib {
# compute Fibonacci number(s)
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
croak("bfib() requires a newer version of the $LIB library.")
unless $LIB->can('_fib');
return $x if $x->modify('bfib');
return $upgrade -> bfib($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
# List context.
if (wantarray) {
return () if $x -> is_nan();
croak("bfib() can't return an infinitely long list of numbers")
if $x -> is_inf();
# Use the backend library to compute the first $x Fibonacci numbers.
my @values = $LIB->_fib($x->{value});
# Make objects out of them. The last element in the array is the
# invocand.
for (my $i = 0 ; $i < $#values ; ++ $i) {
my $fib = $class -> bzero();
$fib -> {value} = $values[$i];
$values[$i] = $fib;
}
$x -> {value} = $values[-1];
$values[-1] = $x;
# If negative, insert sign as appropriate.
if ($x -> is_neg()) {
for (my $i = 2 ; $i <= $#values ; $i += 2) {
$values[$i]{sign} = '-';
}
}
@values = map { $_ -> round(@r) } @values;
return @values;
}
# Scalar context.
else {
return $x if $x->modify('bdfac') || $x -> is_inf('+');
return $x->bnan() if $x -> is_nan() || $x -> is_inf('-');
$x->{sign} = $x -> is_neg() && $x -> is_even() ? '-' : '+';
$x->{value} = $LIB->_fib($x->{value});
return $x->round(@r);
}
}
sub blucas {
# compute Lucas number(s)
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
croak("blucas() requires a newer version of the $LIB library.")
unless $LIB->can('_lucas');
return $x if $x->modify('blucas');
return $upgrade -> blucas($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
# List context.
if (wantarray) {
return () if $x -> is_nan();
croak("blucas() can't return an infinitely long list of numbers")
if $x -> is_inf();
# Use the backend library to compute the first $x Lucas numbers.
my @values = $LIB->_lucas($x->{value});
# Make objects out of them. The last element in the array is the
# invocand.
for (my $i = 0 ; $i < $#values ; ++ $i) {
my $lucas = $class -> bzero();
$lucas -> {value} = $values[$i];
$values[$i] = $lucas;
}
$x -> {value} = $values[-1];
$values[-1] = $x;
# If negative, insert sign as appropriate.
if ($x -> is_neg()) {
for (my $i = 2 ; $i <= $#values ; $i += 2) {
$values[$i]{sign} = '-';
}
}
@values = map { $_ -> round(@r) } @values;
return @values;
}
# Scalar context.
else {
return $x if $x -> is_inf('+');
return $x->bnan() if $x -> is_nan() || $x -> is_inf('-');
$x->{sign} = $x -> is_neg() && $x -> is_even() ? '-' : '+';
$x->{value} = $LIB->_lucas($x->{value});
return $x->round(@r);
}
}
sub blsft {
# (BINT or num_str, BINT or num_str) return BINT
# compute $x << $y, base $n
my ($class, $x, $y, $b, @r);
# Objectify the base only when it is defined, since an undefined base, as
# in $x->blsft(3) or $x->blog(3, undef) means use the default base 2.
if (!ref($_[0]) && $_[0] =~ /^[A-Za-z]|::/) {
# E.g., Math::BigInt->blog(256, 5, 2)
($class, $x, $y, $b, @r) =
defined $_[3] ? objectify(3, @_) : objectify(2, @_);
} else {
# E.g., Math::BigInt::blog(256, 5, 2) or $x->blog(5, 2)
($class, $x, $y, $b, @r) =
defined $_[2] ? objectify(3, @_) : objectify(2, @_);
}
return $x if $x -> modify('blsft');
# The default base is 2.
$b = 2 unless defined $b;
$b = $class -> new($b) unless defined(blessed($b));
# Handle "foreign" objects.
return $upgrade -> blsft($x, $y, $b, @r)
if defined($upgrade) && (!$x -> isa(__PACKAGE__) ||
!$y -> isa(__PACKAGE__) ||
!$b -> isa(__PACKAGE__));
# Handle NaN cases.
return $x -> bnan(@r)
if $x -> is_nan() || $y -> is_nan() || $b -> is_nan();
# blsft($x, -$y, $b) = brsft($x, $y, $b)
return $x -> brsft($y -> copy() -> bneg(), $b, @r) if $y -> is_neg();
# Now handle all cases where at least one operand is ±Inf or the result
# will be ±Inf or NaN.
if ($y -> is_inf("+")) {
if ($b -> is_one("-")) {
return $x -> bnan(@r);
} elsif ($b -> is_one("+")) {
return $x -> round(@r);
} elsif ($b -> is_zero()) {
return $x -> bnan(@r) if $x -> is_inf();
return $x -> bzero(@r);
} else {
return $x -> binf("-", @r) if $x -> is_negative();
return $x -> binf("+", @r) if $x -> is_positive();
return $x -> bnan(@r);
}
}
if ($b -> is_inf()) {
return $x -> bnan(@r) if $x -> is_zero() || $y -> is_zero();
if ($b -> is_inf("-")) {
return $x -> binf("+", @r)
if ($x -> is_negative() && $y -> is_odd() ||
$x -> is_positive() && $y -> is_even());
return $x -> binf("-", @r);
} else {
return $x -> binf("-", @r) if $x -> is_negative();
return $x -> binf("+", @r);
}
}
if ($b -> is_zero()) {
return $x -> round(@r) if $y -> is_zero();
return $x -> bnan(@r) if $x -> is_inf();
return $x -> bzero(@r);
}
if ($x -> is_inf()) {
if ($b -> is_negative()) {
if ($x -> is_inf("-")) {
if ($y -> is_even()) {
return $x -> round(@r);
} else {
return $x -> binf("+", @r);
}
} else {
if ($y -> is_even()) {
return $x -> round(@r);
} else {
return $x -> binf("-", @r);
}
}
} else {
return $x -> round(@r);
}
}
# At this point, we know that both the input and the output is finite.
# Handle some trivial cases.
return $x -> round(@r) if $x -> is_zero() || $y -> is_zero()
|| $b -> is_one("+")
|| $b -> is_one("-") && $y -> is_even();
return $x -> bneg(@r) if $b -> is_one("-") && $y -> is_odd();
# While some of the libraries support an arbitrarily large base, not all of
# them do, so rather than returning an incorrect result in those cases,
# disallow bases that don't work with all libraries.
my $uintmax = ~0;
if ($x -> bcmp($uintmax) > 0) {
$x = $x -> bmul($b -> bpow($y));
} else {
my $neg = 0;
if ($b -> is_negative()) {
$neg = 1 if $y -> is_odd();
$b = $b -> babs();
}
$b = $b -> numify();
$x -> {value} = $LIB -> _lsft($x -> {value}, $y -> {value}, $b);
$x -> {sign} =~ tr/+-/-+/ if $neg;
}
$x -> round(@r);
}
sub brsft {
# (BINT or num_str, BINT or num_str) return BINT
# compute $x >> $y, base $n
my ($class, $x, $y, $b, @r);
# Objectify the base only when it is defined, since an undefined base, as
# in $x->blsft(3) or $x->blog(3, undef) means use the default base 2.
if (!ref($_[0]) && $_[0] =~ /^[A-Za-z]|::/) {
# E.g., Math::BigInt->blog(256, 5, 2)
($class, $x, $y, $b, @r) =
defined $_[3] ? objectify(3, @_) : objectify(2, @_);
} else {
# E.g., Math::BigInt::blog(256, 5, 2) or $x->blog(5, 2)
($class, $x, $y, $b, @r) =
defined $_[2] ? objectify(3, @_) : objectify(2, @_);
}
return $x if $x -> modify('brsft');
# The default base is 2.
$b = 2 unless defined $b;
$b = $class -> new($b) unless defined(blessed($b));
# Handle "foreign" objects.
return $upgrade -> brsft($x, $y, $b, @r)
if defined($upgrade) && (!$x -> isa(__PACKAGE__) ||
!$y -> isa(__PACKAGE__) ||
!$b -> isa(__PACKAGE__));
# Handle NaN cases.
return $x -> bnan(@r)
if $x -> is_nan() || $y -> is_nan() || $b -> is_nan();
# brsft($x, -$y, $b) = blsft($x, $y, $b)
return $x -> blsft($y -> copy() -> bneg(), $b, @r) if $y -> is_neg();
# Now handle all cases where at least one operand is ±Inf or the result
# will be ±Inf or NaN.
if ($b -> is_inf()) {
return $x -> bnan(@r) if $x -> is_inf() || $y -> is_zero();
if ($b -> is_inf("+")) {
if ($x -> is_negative()) {
return $x -> bone("-", @r);
} else {
return $x -> bzero(@r);
}
} else {
if ($x -> is_negative()) {
return $y -> is_odd() ? $x -> bzero(@r)
: $x -> bone("-", @r);
} elsif ($x -> is_positive()) {
return $y -> is_odd() ? $x -> bone("-", @r)
: $x -> bzero(@r);
} else {
return $x -> bzero(@r);
}
}
}
if ($b -> is_zero()) {
return $x -> round(@r) if $y -> is_zero();
return $x -> bnan(@r) if $x -> is_zero();
return $x -> is_negative() ? $x -> binf("-", @r)
: $x -> binf("+", @r);
}
if ($y -> is_inf("+")) {
if ($b -> is_one("-")) {
return $x -> bnan(@r);
} elsif ($b -> is_one("+")) {
return $x -> round(@r);
} else {
return $x -> bnan(@r) if $x -> is_inf();
return $x -> is_negative() ? $x -> bone("-", @r)
: $x -> bzero(@r);
}
}
if ($x -> is_inf()) {
if ($b -> is_negative()) {
if ($x -> is_inf("-")) {
if ($y -> is_even()) {
return $x -> round(@r);
} else {
return $x -> binf("+", @r);
}
} else {
if ($y -> is_even()) {
return $x -> round(@r);
} else {
return $x -> binf("-", @r);
}
}
} else {
return $x -> round(@r);
}
}
# At this point, we know that both the input and the output is finite.
# Handle some trivial cases.
return $x -> round(@r) if $x -> is_zero() || $y -> is_zero()
|| $b -> is_one("+")
|| $b -> is_one("-") && $y -> is_even();
return $x -> bneg(@r) if $b -> is_one("-") && $y -> is_odd();
# We know that $y is positive. Shifting right by a positive amount might
# lead to a non-integer result.
return $upgrade -> brsft($x, $y, $b, @r) if defined($upgrade);
# This only works for negative numbers when shifting in base 2.
if ($x -> is_neg() && $b -> bcmp("2") == 0) {
return $x -> round(@r) if $x -> is_one('-'); # -1 => -1
# Although this is O(N*N) in Math::BigInt::Calc->_as_bin(), it is O(N)
# in Pari et al., but perhaps there is a better emulation for two's
# complement shift ... if $y != 1, we must simulate it by doing:
# convert to bin, flip all bits, shift, and be done
$x = $x -> binc(); # -3 => -2
my $bin = $x -> to_bin(); # convert to string
$bin =~ s/^-//; # strip leading minus
$bin =~ tr/10/01/; # flip bits
my $nbits = CORE::length($bin);
return $x -> bone("-", @r) if $y >= $nbits;
$bin = substr $bin, 0, $nbits - $y; # keep most significant bits
$bin = '1' . $bin; # prepend one dummy '1'
$bin =~ tr/10/01/; # flip bits back
my $res = $class -> from_bin($bin); # convert back from string
$res = $res -> binc(); # remember to increment
$x -> {value} = $res -> {value}; # take over value
return $x -> round(@r);
}
# While some of the libraries support an arbitrarily large base, not all of
# them do, so rather than returning an incorrect result in those cases, use
# division.
my $uintmax = ~0;
if ($x -> bcmp($uintmax) > 0 || $x -> is_neg() || $b -> is_negative()) {
$x = $x -> bdiv($b -> bpow($y));
} else {
$b = $b -> numify();
$x -> {value} = $LIB -> _rsft($x -> {value}, $y -> {value}, $b);
}
return $x -> round(@r);
}
###############################################################################
# Bitwise methods
###############################################################################
# Bitwise left shift.
sub bblsft {
# We don't call objectify(), because the bitwise methods should not
# upgrade/downgrade, even when upgrading/downgrading is enabled.
my ($class, $x, $y, @r);
# $x -> bblsft($y)
if (ref($_[0])) {
($class, $x, $y, @r) = (ref($_[0]), @_);
$y = $y -> as_int()
if ref($y) && !$y -> isa(__PACKAGE__) && $y -> can('as_int');
$y = $class -> new(int($y)) unless ref($y);
}
# $class -> bblsft($x, $y)
else {
($class, $x, $y, @r) = @_;
for ($x, $y) {
$_ = $_ -> as_int()
if ref($_) && !$_ -> isa(__PACKAGE__) && $_ -> can('as_int');
$_ = $class -> new(int($_)) unless ref($_);
}
}
return $x if $x -> modify('bblsft');
return $x -> bnan(@r) if $x -> is_nan() || $y -> is_nan();
# bblsft($x, -$y) = bbrsft($x, $y)
return $x -> bbrsft($y -> copy() -> bneg()) if $y -> is_neg();
# Shifting infinitely far to the left.
if ($y -> is_inf("+")) {
return $x -> binf("+", @r) if $x -> is_pos();
return $x -> binf("-", @r) if $x -> is_neg();
return $x -> bnan(@r);
}
# These cases change nothing.
return $x -> round(@r) if $x -> is_zero() || $x -> is_inf() ||
$y -> is_zero();
$x -> {value} = $LIB -> _lsft($x -> {value}, $y -> {value}, 2);
$x -> round(@r);
}
# Bitwise right shift.
sub bbrsft {
# We don't call objectify(), because the bitwise methods should not
# upgrade/downgrade, even when upgrading/downgrading is enabled.
my ($class, $x, $y, @r);
# $x -> bblsft($y)
if (ref($_[0])) {
($class, $x, $y, @r) = (ref($_[0]), @_);
$y = $y -> as_int()
if ref($y) && !$y -> isa(__PACKAGE__) && $y -> can('as_int');
$y = $class -> new(int($y)) unless ref($y);
}
# $class -> bblsft($x, $y)
else {
($class, $x, $y, @r) = @_;
for ($x, $y) {
$_ = $_ -> as_int()
if ref($_) && !$_ -> isa(__PACKAGE__) && $_ -> can('as_int');
$_ = $class -> new(int($_)) unless ref($_);
}
}
return $x if $x -> modify('bbrsft');
return $x -> bnan(@r) if $x -> is_nan() || $y -> is_nan();
# bbrsft($x, -$y) = bblsft($x, $y)
return $x -> bblsft($y -> copy() -> bneg()) if $y -> is_neg();
# Shifting infinitely far to the right.
if ($y -> is_inf("+")) {
return $x -> bnan(@r) if $x -> is_inf();
return $x -> bone("-", @r) if $x -> is_neg();
return $x -> bzero(@r);
}
# These cases change nothing.
return $x -> round(@r) if $x -> is_zero() || $x -> is_inf() ||
$y -> is_zero();
# At this point, $x is either positive or negative, not zero.
if ($x -> is_pos()) {
$x -> {value} = $LIB -> _rsft($x -> {value}, $y -> {value}, 2);
} else {
my $n = $x -> {value};
my $d = $LIB -> _pow($LIB -> _new("2"), $y -> {value});
my ($p, $q) = $LIB -> _div($n, $d);
$p = $LIB -> _inc($p) unless $LIB -> _is_zero($q);
$x -> {value} = $p;
}
$x -> round(@r);
}
sub band {
#(BINT or num_str, BINT or num_str) return BINT
# compute x & y
my ($class, $x, $y, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (ref($_[0]), @_) : objectify(2, @_);
return $x if $x->modify('band');
return $upgrade -> band($x, $y, @r)
if defined($upgrade) && (!$x -> isa(__PACKAGE__) ||
!$y -> isa(__PACKAGE__));
$r[3] = $y; # no push!
return $x->bnan(@r) if $x->{sign} !~ /^[+-]$/ || $y->{sign} !~ /^[+-]$/;
if ($x->{sign} eq '+' && $y->{sign} eq '+') {
$x->{value} = $LIB->_and($x->{value}, $y->{value});
} else {
($x->{value}, $x->{sign}) = $LIB->_sand($x->{value}, $x->{sign},
$y->{value}, $y->{sign});
}
return $x->round(@r);
}
sub bior {
#(BINT or num_str, BINT or num_str) return BINT
# compute x | y
my ($class, $x, $y, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (ref($_[0]), @_) : objectify(2, @_);
return $x if $x->modify('bior');
return $upgrade -> bior($x, $y, @r)
if defined($upgrade) && (!$x -> isa(__PACKAGE__) ||
!$y -> isa(__PACKAGE__));
$r[3] = $y; # no push!
return $x->bnan() if ($x->{sign} !~ /^[+-]$/ || $y->{sign} !~ /^[+-]$/);
if ($x->{sign} eq '+' && $y->{sign} eq '+') {
$x->{value} = $LIB->_or($x->{value}, $y->{value});
} else {
($x->{value}, $x->{sign}) = $LIB->_sor($x->{value}, $x->{sign},
$y->{value}, $y->{sign});
}
return $x->round(@r);
}
sub bxor {
#(BINT or num_str, BINT or num_str) return BINT
# compute x ^ y
my ($class, $x, $y, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (ref($_[0]), @_) : objectify(2, @_);
return $x if $x->modify('bxor');
return $upgrade -> bxor($x, $y, @r)
if defined($upgrade) && (!$x -> isa(__PACKAGE__) ||
!$y -> isa(__PACKAGE__));
$r[3] = $y; # no push!
return $x->bnan(@r) if $x->{sign} !~ /^[+-]$/ || $y->{sign} !~ /^[+-]$/;
if ($x->{sign} eq '+' && $y->{sign} eq '+') {
$x->{value} = $LIB->_xor($x->{value}, $y->{value});
} else {
($x->{value}, $x->{sign}) = $LIB->_sxor($x->{value}, $x->{sign},
$y->{value}, $y->{sign});
}
return $x->round(@r);
}
sub bnot {
# (num_str or BINT) return BINT
# represent ~x as twos-complement number
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
return $x if $x->modify('bnot');
return $upgrade -> bnot($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
$x -> binc() -> bneg(@r);
}
###############################################################################
# Rounding methods
###############################################################################
sub round {
# Round $self according to given parameters, or given second argument's
# parameters or global defaults
my ($class, $self, @args) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
# These signal no rounding:
#
# $x->round(undef)
# $x->round(undef, undef, ...)
#
# The "@args <= 3" is necessary because the final set of parameters that
# will be used for rounding depend on the "extra arguments", if any.
if (@args == 1 && !defined($args[0]) ||
@args >= 2 && @args <= 3 && !defined($args[0]) && !defined($args[1]))
{
$self->{accuracy} = undef;
$self->{precision} = undef;
return $self;
}
my ($a, $p, $r) = splice @args, 0, 3;
# $a accuracy, if given by caller
# $p precision, if given by caller
# $r round_mode, if given by caller
# @args all 'other' arguments (0 for unary, 1 for binary ops)
if (defined $a) {
croak "accuracy must be a number, not '$a'"
unless $a =~/^[+-]?(?:\d+(?:\.\d*)?|\.\d+)(?:[Ee][+-]?\d+)?\z/;
}
if (defined $p) {
croak "precision must be a number, not '$p'"
unless $p =~/^[+-]?(?:\d+(?:\.\d*)?|\.\d+)(?:[Ee][+-]?\d+)?\z/;
}
# now pick $a or $p, but only if we have got "arguments"
if (!defined $a) {
foreach ($self, @args) {
# take the defined one, or if both defined, the one that is smaller
$a = $_->{accuracy}
if (defined $_->{accuracy}) && (!defined $a || $_->{accuracy} < $a);
}
}
if (!defined $p) {
# even if $a is defined, take $p, to signal error for both defined
foreach ($self, @args) {
# take the defined one, or if both defined, the one that is bigger
# -2 > -3, and 3 > 2
$p = $_->{precision}
if (defined $_->{precision}) && (!defined $p || $_->{precision} > $p);
}
}
# if still none defined, use globals
unless (defined $a || defined $p) {
$a = $class -> accuracy();
$p = $class -> precision();
}
# A == 0 is useless, so undef it to signal no rounding
$a = undef if defined $a && $a == 0;
# no rounding today?
return $self unless defined $a || defined $p; # early out
# set A and set P is an fatal error
return $self->bnan() if defined $a && defined $p;
$r = $class -> round_mode() unless defined $r;
if ($r !~ /^(even|odd|[+-]inf|zero|trunc|common)$/) {
croak("Unknown round mode '$r'");
}
# now round, by calling either bround or bfround:
if (defined $a) {
$self = $self->bround(int($a), $r)
if !defined $self->{accuracy} || $self->{accuracy} >= $a;
} else { # both can't be undefined due to early out
$self = $self->bfround(int($p), $r)
if !defined $self->{precision} || $self->{precision} <= $p;
}
# bround() or bfround() already called bnorm() if nec.
$self;
}
sub bround {
# accuracy: +$n preserve $n digits from left,
# -$n preserve $n digits from right (f.i. for 0.1234 style in MBF)
# no-op for $n == 0
# and overwrite the rest with 0's, return normalized number
# do not return $x->bnorm(), but $x
my ($class, $x, @a) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
my ($scale, $mode) = $x->_scale_a(@a);
return $x if !defined $scale || $x->modify('bround'); # no-op
if ($x->is_zero() || $scale == 0) {
$x->{accuracy} = $scale if !defined $x->{accuracy} || $x->{accuracy} > $scale; # 3 > 2
return $x;
}
return $x if $x->{sign} !~ /^[+-]$/; # inf, NaN
# we have fewer digits than we want to scale to
my $len = $x->length();
# convert $scale to a scalar in case it is an object (put's a limit on the
# number length, but this would already limited by memory constraints),
# makes it faster
$scale = $scale->numify() if ref ($scale);
# scale < 0, but > -len (not >=!)
if (($scale < 0 && $scale < -$len-1) || ($scale >= $len)) {
$x->{accuracy} = $scale if !defined $x->{accuracy} || $x->{accuracy} > $scale; # 3 > 2
return $x;
}
# count of 0's to pad, from left (+) or right (-): 9 - +6 => 3, or |-6| => 6
my ($pad, $digit_round, $digit_after);
$pad = $len - $scale;
$pad = abs($scale-1) if $scale < 0;
# do not use digit(), it is very costly for binary => decimal
# getting the entire string is also costly, but we need to do it only once
my $xs = $LIB->_str($x->{value});
my $pl = -$pad-1;
# pad: 123: 0 => -1, at 1 => -2, at 2 => -3, at 3 => -4
# pad+1: 123: 0 => 0, at 1 => -1, at 2 => -2, at 3 => -3
$digit_round = '0';
$digit_round = substr($xs, $pl, 1) if $pad <= $len;
$pl++;
$pl ++ if $pad >= $len;
$digit_after = '0';
$digit_after = substr($xs, $pl, 1) if $pad > 0;
# in case of 01234 we round down, for 6789 up, and only in case 5 we look
# closer at the remaining digits of the original $x, remember decision
my $round_up = 1; # default round up
$round_up -- if
($mode eq 'trunc') || # trunc by round down
($digit_after =~ /[01234]/) || # round down anyway,
# 6789 => round up
($digit_after eq '5') && # not 5000...0000
($x->_scan_for_nonzero($pad, $xs, $len) == 0) &&
(
($mode eq 'even') && ($digit_round =~ /[24680]/) ||
($mode eq 'odd') && ($digit_round =~ /[13579]/) ||
($mode eq '+inf') && ($x->{sign} eq '-') ||
($mode eq '-inf') && ($x->{sign} eq '+') ||
($mode eq 'zero') # round down if zero, sign adjusted below
);
my $put_back = 0; # not yet modified
if (($pad > 0) && ($pad <= $len)) {
substr($xs, -$pad, $pad) = '0' x $pad; # replace with '00...'
$xs =~ s/^0+(\d)/$1/; # "00000" -> "0"
$put_back = 1; # need to put back
} elsif ($pad > $len) {
$x = $x->bzero(); # round to '0'
}
if ($round_up) { # what gave test above?
$put_back = 1; # need to put back
$pad = $len, $xs = '0' x $pad if $scale < 0; # tlr: whack 0.51=>1.0
# we modify directly the string variant instead of creating a number and
# adding it, since that is faster (we already have the string)
my $c = 0;
$pad ++; # for $pad == $len case
while ($pad <= $len) {
$c = substr($xs, -$pad, 1) + 1;
$c = '0' if $c eq '10';
substr($xs, -$pad, 1) = $c;
$pad++;
last if $c != 0; # no overflow => early out
}
$xs = '1'.$xs if $c == 0;
}
$x->{value} = $LIB->_new($xs) if $put_back == 1; # put back, if needed
$x->{accuracy} = $scale if $scale >= 0;
if ($scale < 0) {
$x->{accuracy} = $len+$scale;
$x->{accuracy} = 0 if $scale < -$len;
}
$x;
}
sub bfround {
# precision: round to the $Nth digit left (+$n) or right (-$n) from the '.'
# $n == 0 || $n == 1 => round to integer
my ($class, $x, @p) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
my ($scale, $mode) = $x->_scale_p(@p);
return $x if !defined $scale || $x->modify('bfround'); # no-op
# no-op for Math::BigInt objects if $n <= 0
$x = $x->bround($x->length()-$scale, $mode) if $scale > 0;
$x->{accuracy} = undef;
$x->{precision} = $scale; # store new precision
$x;
}
sub fround {
# Exists to make life easier for switch between MBF and MBI (should we
# autoload fxxx() like MBF does for bxxx()?)
my $x = shift;
$x = __PACKAGE__->new($x) unless ref $x;
$x->bround(@_);
}
sub bfloor {
# round towards minus infinity; no-op since it's already integer
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
return $upgrade -> bfloor($x)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
$x->round(@r);
}
sub bceil {
# round towards plus infinity; no-op since it's already int
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
return $upgrade -> bceil($x)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
$x->round(@r);
}
sub bint {
# round towards zero; no-op since it's already integer
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
return $upgrade -> bint($x)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
$x->round(@r);
}
###############################################################################
# Other mathematical methods
###############################################################################
sub bgcd {
# (BINT or num_str, BINT or num_str) return BINT
# does not modify arguments, but returns new object
# GCD -- Euclid's algorithm, variant C (Knuth Vol 3, pg 341 ff)
# Class::method(...) -> Class->method(...)
unless (@_ && (defined(blessed($_[0])) && $_[0] -> isa(__PACKAGE__) ||
$_[0] =~ /^[a-z]\w*(?:::[a-z]\w*)*$/i))
{
#carp "Using ", (caller(0))[3], "() as a function is deprecated;",
# " use is as a method instead";
unshift @_, __PACKAGE__;
}
my ($class, @args) = objectify(0, @_);
# Upgrade?
if (defined $upgrade) {
my $do_upgrade = 0;
for my $arg (@args) {
unless ($arg -> isa(__PACKAGE__)) {
$do_upgrade = 1;
last;
}
}
return $upgrade -> bgcd(@args) if $do_upgrade;
}
my $x = shift @args;
$x = defined(blessed($x)) && $x -> isa(__PACKAGE__) ? $x -> copy()
: $class -> new($x);
return $class->bnan() if $x->{sign} !~ /^[+-]$/; # x NaN?
while (@args) {
my $y = shift @args;
$y = $class->new($y)
unless defined(blessed($y)) && $y -> isa(__PACKAGE__);
return $class->bnan() if $y->{sign} !~ /^[+-]$/; # y NaN?
$x->{value} = $LIB->_gcd($x->{value}, $y->{value});
last if $LIB->_is_one($x->{value});
}
return $x -> babs();
}
sub blcm {
# (BINT or num_str, BINT or num_str) return BINT
# does not modify arguments, but returns new object
# Least Common Multiple
# Class::method(...) -> Class->method(...)
unless (@_ && (defined(blessed($_[0])) && $_[0] -> isa(__PACKAGE__) ||
$_[0] =~ /^[a-z]\w*(?:::[a-z]\w*)*$/i))
{
#carp "Using ", (caller(0))[3], "() as a function is deprecated;",
# " use is as a method instead";
unshift @_, __PACKAGE__;
}
my ($class, @args) = objectify(0, @_);
# Upgrade?
if (defined $upgrade) {
my $do_upgrade = 0;
for my $arg (@args) {
unless ($arg -> isa(__PACKAGE__)) {
$do_upgrade = 1;
last;
}
}
return $upgrade -> blcm(@args) if $do_upgrade;
}
my $x = shift @args;
$x = defined(blessed($x)) && $x -> isa(__PACKAGE__) ? $x -> copy()
: $class -> new($x);
return $class->bnan() if $x->{sign} !~ /^[+-]$/; # x NaN?
while (@args) {
my $y = shift @args;
$y = $class -> new($y)
unless defined(blessed($y)) && $y -> isa(__PACKAGE__);
return $x->bnan() if $y->{sign} !~ /^[+-]$/; # y not integer
$x -> {value} = $LIB->_lcm($x -> {value}, $y -> {value});
}
return $x -> babs();
}
###############################################################################
# Object property methods
###############################################################################
sub sign {
# return the sign of the number: +/-/-inf/+inf/NaN
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
$x->{sign};
}
sub digit {
# return the nth decimal digit, negative values count backward, 0 is right
my (undef, $x, $n, @r) = ref($_[0]) ? (undef, @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
$n = $n->numify() if ref($n);
$LIB->_digit($x->{value}, $n || 0);
}
sub bdigitsum {
# like digitsum(), but assigns the result to the invocand
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
return $x if $x -> is_nan();
return $x -> bnan() if $x -> is_inf();
$x -> {value} = $LIB -> _digitsum($x -> {value});
$x -> {sign} = '+';
return $x;
}
sub digitsum {
# compute sum of decimal digits and return it
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
return $class -> bnan() if $x -> is_nan();
return $class -> bnan() if $x -> is_inf();
my $y = $class -> bzero();
$y -> {value} = $LIB -> _digitsum($x -> {value});
$y -> round(@r);
}
sub length {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
my $e = $LIB->_len($x->{value});
wantarray ? ($e, 0) : $e;
}
sub exponent {
# return a copy of the exponent (here always 0, NaN or 1 for $m == 0)
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
# Upgrade?
return $upgrade -> exponent($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
if ($x->{sign} !~ /^[+-]$/) {
my $s = $x->{sign};
$s =~ s/^[+-]//; # NaN, -inf, +inf => NaN or inf
return $class->new($s, @r);
}
return $class->bzero(@r) if $x->is_zero();
# 12300 => 2 trailing zeros => exponent is 2
$class->new($LIB->_zeros($x->{value}), @r);
}
sub mantissa {
# return the mantissa (compatible to Math::BigFloat, e.g. reduced)
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
# Upgrade?
return $upgrade -> mantissa($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
if ($x->{sign} !~ /^[+-]$/) {
# for NaN, +inf, -inf: keep the sign
return $class->new($x->{sign}, @r);
}
my $m = $x->copy();
$m -> precision(undef);
$m -> accuracy(undef);
# that's a bit inefficient:
my $zeros = $LIB->_zeros($m->{value});
$m = $m->brsft($zeros, 10) if $zeros != 0;
$m -> round(@r);
}
sub parts {
# return a copy of both the exponent and the mantissa
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
# Upgrade?
return $upgrade -> parts($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
($x->mantissa(@r), $x->exponent(@r));
}
# Parts used for scientific notation with significand/mantissa and exponent as
# integers. E.g., "12345.6789" is returned as "123456789" (mantissa) and "-4"
# (exponent).
sub sparts {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
# Not-a-number.
if ($x -> is_nan()) {
my $mant = $class -> bnan(@r); # mantissa
return $mant unless wantarray; # scalar context
my $expo = $class -> bnan(@r); # exponent
return ($mant, $expo); # list context
}
# Infinity.
if ($x -> is_inf()) {
my $mant = $class -> binf($x->{sign}, @r); # mantissa
return $mant unless wantarray; # scalar context
my $expo = $class -> binf('+', @r); # exponent
return ($mant, $expo); # list context
}
# Upgrade?
return $upgrade -> sparts($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
# Finite number.
my $mant = $x -> copy();
my $nzeros = $LIB -> _zeros($mant -> {value});
$mant -> {value}
= $LIB -> _rsft($mant -> {value}, $LIB -> _new($nzeros), 10)
if $nzeros != 0;
return $mant unless wantarray;
my $expo = $class -> new($nzeros, @r);
return ($mant, $expo);
}
# Parts used for normalized notation with significand/mantissa as either 0 or a
# number in the semi-open interval [1,10). E.g., "12345.6789" is returned as
# "1.23456789" and "4".
sub nparts {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
# Not-a-Number and Infinity.
return $x -> sparts(@r) if $x -> is_nan() || $x -> is_inf();
# Upgrade?
return $upgrade -> nparts($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
# Finite number.
my ($mant, $expo) = $x -> sparts(@r);
if ($mant -> bcmp(0)) {
my ($ndigtot, $ndigfrac) = $mant -> length();
my $expo10adj = $ndigtot - $ndigfrac - 1;
if ($expo10adj > 0) { # if mantissa is not an integer
return $upgrade -> nparts($x, @r) if defined $upgrade;
$mant = $mant -> bnan(@r);
return $mant unless wantarray;
$expo = $expo -> badd($expo10adj, @r);
return ($mant, $expo);
}
}
return $mant unless wantarray;
return ($mant, $expo);
}
# Parts used for engineering notation with significand/mantissa as either 0 or a
# number in the semi-open interval [1,1000) and the exponent is a multiple of 3.
# E.g., "12345.6789" is returned as "12.3456789" and "3".
sub eparts {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
# Not-a-number and Infinity.
return $x -> sparts(@r) if $x -> is_nan() || $x -> is_inf();
# Upgrade?
return $upgrade -> eparts($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
# Finite number.
my ($mant, $expo) = $x -> sparts(@r);
if ($mant -> bcmp(0)) {
my $ndigmant = $mant -> length();
$expo = $expo -> badd($ndigmant, @r);
# $c is the number of digits that will be in the integer part of the
# final mantissa.
my $c = $expo -> copy() -> bdec() -> bmod(3) -> binc();
$expo = $expo -> bsub($c);
if ($ndigmant > $c) {
return $upgrade -> eparts($x, @r) if defined $upgrade;
$mant = $mant -> bnan(@r);
return $mant unless wantarray;
return ($mant, $expo);
}
$mant = $mant -> blsft($c - $ndigmant, 10, @r);
}
return $mant unless wantarray;
return ($mant, $expo);
}
# Parts used for decimal notation, e.g., "12345.6789" is returned as "12345"
# (integer part) and "0.6789" (fraction part).
sub dparts {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
# Not-a-number.
if ($x -> is_nan()) {
my $int = $class -> bnan(@r);
return $int unless wantarray;
my $frc = $class -> bzero(@r); # or NaN?
return ($int, $frc);
}
# Infinity.
if ($x -> is_inf()) {
my $int = $class -> binf($x->{sign}, @r);
return $int unless wantarray;
my $frc = $class -> bzero(@r);
return ($int, $frc);
}
# Upgrade?
return $upgrade -> dparts($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
# Finite number.
my $int = $x -> copy() -> round(@r);
return $int unless wantarray;
my $frc = $class -> bzero(@r);
return ($int, $frc);
}
# Fractional parts with the numerator and denominator as integers. E.g.,
# "123.4375" is returned as "1975" and "16".
sub fparts {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
# NaN => NaN/NaN
if ($x -> is_nan()) {
return $class -> bnan(@r) unless wantarray;
return $class -> bnan(@r), $class -> bnan(@r);
}
# ±Inf => ±Inf/1
if ($x -> is_inf()) {
my $numer = $class -> binf($x->{sign}, @r);
return $numer unless wantarray;
my $denom = $class -> bone(@r);
return $numer, $denom;
}
# Upgrade?
return $upgrade -> fparts($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
# N => N/1
my $numer = $x -> copy() -> round(@r);
return $numer unless wantarray;
my $denom = $class -> bone(@r);
return $numer, $denom;
}
sub numerator {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
return $upgrade -> numerator($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
return $x -> copy() -> round(@r);
}
sub denominator {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
return $upgrade -> denominator($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
return $x -> is_nan() ? $class -> bnan(@r) : $class -> bone(@r);
}
###############################################################################
# String conversion methods
###############################################################################
sub bstr {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
# Inf and NaN
if ($x->{sign} ne '+' && $x->{sign} ne '-') {
return $x->{sign} unless $x->{sign} eq '+inf'; # -inf, NaN
return 'inf'; # +inf
}
# Upgrade?
return $upgrade -> bstr($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
# Finite number
my $str = $LIB->_str($x->{value});
return $x->{sign} eq '-' ? "-$str" : $str;
}
# Scientific notation with significand/mantissa as an integer, e.g., "12345" is
# written as "1.2345e+4".
sub bsstr {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
# Inf and NaN
if ($x->{sign} ne '+' && $x->{sign} ne '-') {
return $x->{sign} unless $x->{sign} eq '+inf'; # -inf, NaN
return 'inf'; # +inf
}
# Upgrade?
return $upgrade -> bsstr($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
# Finite number
my $expo = $LIB -> _zeros($x->{value});
my $mant = $LIB -> _str($x->{value});
$mant = substr($mant, 0, -$expo) if $expo; # strip trailing zeros
($x->{sign} eq '-' ? '-' : '') . $mant . 'e+' . $expo;
}
# Normalized notation, e.g., "12345" is written as "1.2345e+4".
sub bnstr {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
# Inf and NaN
if ($x->{sign} ne '+' && $x->{sign} ne '-') {
return $x->{sign} unless $x->{sign} eq '+inf'; # -inf, NaN
return 'inf'; # +inf
}
# Upgrade?
return $upgrade -> bnstr($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
# Finite number
my $expo = $LIB -> _zeros($x->{value});
my $mant = $LIB -> _str($x->{value});
$mant = substr($mant, 0, -$expo) if $expo; # strip trailing zeros
my $mantlen = CORE::length($mant);
if ($mantlen > 1) {
$expo += $mantlen - 1; # adjust exponent
substr $mant, 1, 0, "."; # insert decimal point
}
($x->{sign} eq '-' ? '-' : '') . $mant . 'e+' . $expo;
}
# Engineering notation, e.g., "12345" is written as "12.345e+3".
sub bestr {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
# Inf and NaN
if ($x->{sign} ne '+' && $x->{sign} ne '-') {
return $x->{sign} unless $x->{sign} eq '+inf'; # -inf, NaN
return 'inf'; # +inf
}
# Upgrade?
return $upgrade -> bestr($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
# Finite number
my $expo = $LIB -> _zeros($x->{value}); # number of trailing zeros
my $mant = $LIB -> _str($x->{value}); # mantissa as a string
$mant = substr($mant, 0, -$expo) if $expo; # strip trailing zeros
my $mantlen = CORE::length($mant); # length of mantissa
$expo += $mantlen;
my $dotpos = ($expo - 1) % 3 + 1; # offset of decimal point
$expo -= $dotpos;
if ($dotpos < $mantlen) {
substr $mant, $dotpos, 0, "."; # insert decimal point
} elsif ($dotpos > $mantlen) {
$mant .= "0" x ($dotpos - $mantlen); # append zeros
}
($x->{sign} eq '-' ? '-' : '') . $mant . 'e+' . $expo;
}
# Decimal notation, e.g., "12345" (no exponent).
sub bdstr {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
# Inf and NaN
if ($x->{sign} ne '+' && $x->{sign} ne '-') {
return $x->{sign} unless $x->{sign} eq '+inf'; # -inf, NaN
return 'inf'; # +inf
}
# Upgrade?
return $upgrade -> bdstr($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
# Finite number
($x->{sign} eq '-' ? '-' : '') . $LIB->_str($x->{value});
}
# Fraction notation, e.g., "123.4375" is written as "1975/16", but "123" is
# written as "123", not "123/1".
sub bfstr {
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
# Inf and NaN
if ($x->{sign} ne '+' && $x->{sign} ne '-') {
return $x->{sign} unless $x->{sign} eq '+inf'; # -inf, NaN
return 'inf'; # +inf
}
# Upgrade?
return $upgrade -> bfstr($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
# Finite number
($x->{sign} eq '-' ? '-' : '') . $LIB->_str($x->{value});
}
sub to_hex {
# return as hex string with no prefix
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
# Inf and NaN
if ($x->{sign} ne '+' && $x->{sign} ne '-') {
return $x->{sign} unless $x->{sign} eq '+inf'; # -inf, NaN
return 'inf'; # +inf
}
# Upgrade?
return $upgrade -> to_hex($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
# Finite number
my $hex = $LIB->_to_hex($x->{value});
return $x->{sign} eq '-' ? "-$hex" : $hex;
}
sub to_oct {
# return as octal string with no prefix
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
# Inf and NaN
if ($x->{sign} ne '+' && $x->{sign} ne '-') {
return $x->{sign} unless $x->{sign} eq '+inf'; # -inf, NaN
return 'inf'; # +inf
}
# Upgrade?
return $upgrade -> to_oct($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
# Finite number
my $oct = $LIB->_to_oct($x->{value});
return $x->{sign} eq '-' ? "-$oct" : $oct;
}
sub to_bin {
# return as binary string with no prefix
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
# Inf and NaN
if ($x->{sign} ne '+' && $x->{sign} ne '-') {
return $x->{sign} unless $x->{sign} eq '+inf'; # -inf, NaN
return 'inf'; # +inf
}
# Upgrade?
return $upgrade -> to_bin($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
# Finite number
my $bin = $LIB->_to_bin($x->{value});
return $x->{sign} eq '-' ? "-$bin" : $bin;
}
sub to_bytes {
# return a byte string
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
croak("to_bytes() requires a finite, non-negative integer")
if $x -> is_neg() || ! $x -> is_int();
return $upgrade -> to_bytes($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
croak("to_bytes() requires a newer version of the $LIB library.")
unless $LIB->can('_to_bytes');
return $LIB->_to_bytes($x->{value});
}
sub to_base {
# return a base anything string
# $cs is the collation sequence
my ($class, $x, $base, $cs, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (ref($_[0]), @_) : objectify(2, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
croak("the value to convert must be a finite, non-negative integer")
if $x -> is_neg() || !$x -> is_int();
croak("the base must be a finite integer >= 2")
if $base < 2 || ! $base -> is_int();
# If no collating sequence is given, pass some of the conversions to
# methods optimized for those cases.
unless (defined $cs) {
return $x -> to_bin() if $base == 2;
return $x -> to_oct() if $base == 8;
return uc $x -> to_hex() if $base == 16;
return $x -> bstr() if $base == 10;
}
croak("to_base() requires a newer version of the $LIB library.")
unless $LIB->can('_to_base');
return $upgrade -> to_base($x, $base, $cs, @r)
if defined($upgrade) && (!$x -> isa(__PACKAGE__) ||
!$base -> isa(__PACKAGE__));
return $LIB->_to_base($x->{value}, $base -> {value},
defined($cs) ? $cs : ());
}
sub to_base_num {
# return a base anything array ref, e.g.,
# Math::BigInt -> new(255) -> to_base_num(10) returns [2, 5, 5];
# $cs is the collation sequence
my ($class, $x, $base, @r) = ref($_[0]) && ref($_[0]) eq ref($_[1])
? (ref($_[0]), @_) : objectify(2, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
croak("the value to convert must be a finite non-negative integer")
if $x -> is_neg() || !$x -> is_int();
croak("the base must be a finite integer >= 2")
if $base < 2 || ! $base -> is_int();
croak("to_base() requires a newer version of the $LIB library.")
unless $LIB->can('_to_base');
return $upgrade -> to_base_num($x, $base, @r)
if defined($upgrade) && (!$x -> isa(__PACKAGE__) ||
!$base -> isa(__PACKAGE__));
# Get a reference to an array of library thingies, and replace each element
# with a Math::BigInt object using that thingy.
my $vals = $LIB -> _to_base_num($x->{value}, $base -> {value});
for my $i (0 .. $#$vals) {
my $x = $class -> bzero();
$x -> {value} = $vals -> [$i];
$vals -> [$i] = $x;
}
return $vals;
}
sub as_hex {
# return as hex string, with prefixed 0x
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
return $x->bstr() if $x->{sign} !~ /^[+-]$/; # inf, nan etc
return $upgrade -> as_hex($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
my $hex = $LIB->_as_hex($x->{value});
return $x->{sign} eq '-' ? "-$hex" : $hex;
}
sub as_oct {
# return as octal string, with prefixed 0
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
return $x->bstr() if $x->{sign} !~ /^[+-]$/; # inf, nan etc
return $upgrade -> as_oct($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
my $oct = $LIB->_as_oct($x->{value});
return $x->{sign} eq '-' ? "-$oct" : $oct;
}
sub as_bin {
# return as binary string, with prefixed 0b
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
return $x->bstr() if $x->{sign} !~ /^[+-]$/; # inf, nan etc
return $upgrade -> as_bin($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
my $bin = $LIB->_as_bin($x->{value});
return $x->{sign} eq '-' ? "-$bin" : $bin;
}
*as_bytes = \&to_bytes;
###############################################################################
# Other conversion methods
###############################################################################
sub numify {
# Make a Perl scalar number from a Math::BigInt object.
my ($class, $x, @r) = ref($_[0]) ? (ref($_[0]), @_) : objectify(1, @_);
carp "Rounding is not supported for ", (caller(0))[3], "()" if @r;
if ($x -> is_nan()) {
require Math::Complex;
my $inf = $Math::Complex::Inf;
return $inf - $inf;
}
if ($x -> is_inf()) {
require Math::Complex;
my $inf = $Math::Complex::Inf;
return $x -> is_negative() ? -$inf : $inf;
}
return $upgrade -> numify($x, @r)
if defined($upgrade) && !$x -> isa(__PACKAGE__);
my $num = 0 + $LIB->_num($x->{value});
return $x->{sign} eq '-' ? -$num : $num;
}
###############################################################################
# Private methods and functions.
###############################################################################
sub objectify {
# Convert strings and "foreign objects" to the objects we want.
# The first argument, $count, is the number of following arguments that
# objectify() looks at and converts to objects. The first is a classname.
# If the given count is 0, all arguments will be used.
# After the count is read, objectify obtains the name of the class to which
# the following arguments are converted. If the second argument is a
# reference, use the reference type as the class name. Otherwise, if it is
# a string that looks like a class name, use that. Otherwise, use $class.
# Caller: Gives us:
#
# $x->badd(1); => ref x, scalar y
# Class->badd(1, 2); => classname x (scalar), scalar x, scalar y
# Class->badd(Class->(1), 2); => classname x (scalar), ref x, scalar y
# Math::BigInt::badd(1, 2); => scalar x, scalar y
# A shortcut for the common case $x->unary_op(), in which case the argument
# list is (0, $x) or (1, $x).
return (ref($_[1]), $_[1]) if @_ == 2 && ($_[0] || 0) == 1 && ref($_[1]);
# Check the context.
unless (wantarray) {
croak(__PACKAGE__ . "::objectify() needs list context");
}
# Get the number of arguments to objectify.
my $count = shift;
# Initialize the output array.
my @a = @_;
# If the first argument is a reference, use that reference type as our
# class name. Otherwise, if the first argument looks like a class name,
# then use that as our class name. Otherwise, use the default class name.
my $class;
if (ref($a[0])) { # reference?
$class = ref($a[0]);
} elsif ($a[0] =~ /^[A-Z].*::/) { # string with class name?
$class = shift @a;
} else {
$class = __PACKAGE__; # default class name
}
$count ||= @a;
unshift @a, $class;
# What we upgrade to, if anything. Note that we need the whole upgrade
# chain, since there might be multiple levels of upgrading. E.g., class A
# upgrades to class B, which upgrades to class C. Delay getting the chain
# until we actually need it.
my @upg = ();
my $have_upgrade_chain = 0;
# Disable downgrading, because Math::BigFloat -> foo('1.0', '2.0') needs
# floats.
my $dng = $class -> downgrade();
$class -> downgrade(undef);
ARG: for my $i (1 .. $count) {
my $ref = ref $a[$i];
# Perl scalars are fed to the appropriate constructor.
unless ($ref) {
$a[$i] = $class -> new($a[$i]);
next;
}
# If it is an object of the right class, all is fine.
next if $ref -> isa($class);
# Upgrading is OK, so skip further tests if the argument is upgraded,
# but first get the whole upgrade chain if we haven't got it yet.
unless ($have_upgrade_chain) {
my $cls = $class;
my $upg = $cls -> upgrade();
while (defined $upg) {
last if $upg eq $cls;
push @upg, $upg;
$cls = $upg;
$upg = $cls -> upgrade();
}
$have_upgrade_chain = 1;
}
for my $upg (@upg) {
next ARG if $ref -> isa($upg);
}
# See if we can call one of the as_xxx() methods. We don't know whether
# the as_xxx() method returns an object or a scalar, so re-check
# afterwards.
my $recheck = 0;
if ($class -> isa('Math::BigInt')) {
if ($a[$i] -> can('as_int')) {
$a[$i] = $a[$i] -> as_int();
$recheck = 1;
} elsif ($a[$i] -> can('as_number')) {
$a[$i] = $a[$i] -> as_number();
$recheck = 1;
}
}
elsif ($class -> isa('Math::BigRat')) {
if ($a[$i] -> can('as_rat')) {
$a[$i] = $a[$i] -> as_rat();
$recheck = 1;
}
}
elsif ($class -> isa('Math::BigFloat')) {
if ($a[$i] -> can('as_float')) {
$a[$i] = $a[$i] -> as_float();
$recheck = 1;
}
}
# If we called one of the as_xxx() methods, recheck.
if ($recheck) {
$ref = ref($a[$i]);
# Perl scalars are fed to the appropriate constructor.
unless ($ref) {
$a[$i] = $class -> new($a[$i]);
next;
}
# If it is an object of the right class, all is fine.
next if $ref -> isa($class);
}
# Last resort.
$a[$i] = $class -> new($a[$i]);
}
# Restore the downgrading.
$class -> downgrade($dng);
return @a;
}
sub import {
my $class = shift;
$IMPORT++; # remember we did import()
my @a; # unrecognized arguments
while (@_) {
my $param = shift;
# Enable overloading of constants.
if ($param eq ':constant') {
overload::constant
integer => sub {
$class -> new(shift);
},
float => sub {
$class -> new(shift);
},
binary => sub {
# E.g., a literal 0377 shall result in an object whose value
# is decimal 255, but new("0377") returns decimal 377.
return $class -> from_oct($_[0]) if $_[0] =~ /^0_*[0-7]/;
$class -> new(shift);
};
next;
}
# Upgrading.
if ($param eq 'upgrade') {
$class -> upgrade(shift);
next;
}
# Downgrading.
if ($param eq 'downgrade') {
$class -> downgrade(shift);
next;
}
# Accuracy.
if ($param eq 'accuracy') {
$class -> accuracy(shift);
next;
}
# Precision.
if ($param eq 'precision') {
$class -> precision(shift);
next;
}
# Rounding mode.
if ($param eq 'round_mode') {
$class -> round_mode(shift);
next;
}
# Fall-back accuracy.
if ($param eq 'div_scale') {
$class -> div_scale(shift);
next;
}
# Backend library.
if ($param =~ /^(lib|try|only)\z/) {
# try => 0 (no warn if unavailable module)
# lib => 1 (warn on fallback)
# only => 2 (die on fallback)
# Get the list of user-specified libraries.
croak "Library argument for import parameter '$param' is missing"
unless @_;
my $libs = shift;
croak "Library argument for import parameter '$param' is undefined"
unless defined($libs);
# Check and clean up the list of user-specified libraries.
my @libs;
for my $lib (split /,/, $libs) {
$lib =~ s/^\s+//;
$lib =~ s/\s+$//;
if ($lib =~ /[^a-zA-Z0-9_:]/) {
carp "Library name '$lib' contains invalid characters";
next;
}
if (! CORE::length $lib) {
carp "Library name is empty";
next;
}
$lib = "Math::BigInt::$lib" if $lib !~ /^Math::BigInt::/i;
# If a library has already been loaded, that is OK only if the
# requested library is identical to the loaded one.
if (defined($LIB)) {
if ($lib ne $LIB) {
#carp "Library '$LIB' has already been loaded, so",
# " ignoring requested library '$lib'";
}
next;
}
push @libs, $lib;
}
next if defined $LIB;
croak "Library list contains no valid libraries" unless @libs;
# Try to load the specified libraries, if any.
for (my $i = 0 ; $i <= $#libs ; $i++) {
my $lib = $libs[$i];
eval "require $lib";
unless ($@) {
$LIB = $lib;
last;
}
}
next if defined $LIB;
# No library has been loaded, and none of the requested libraries
# could be loaded, and fallback and the user doesn't allow fallback.
if ($param eq 'only') {
croak "Couldn't load the specified math lib(s) ",
join(", ", map "'$_'", @libs),
", and fallback to '$DEFAULT_LIB' is not allowed";
}
# No library has been loaded, and none of the requested libraries
# could be loaded, but the user accepts the use of a fallback
# library, so try to load it.
eval "require $DEFAULT_LIB";
if ($@) {
croak "Couldn't load the specified math lib(s) ",
join(", ", map "'$_'", @libs),
", not even the fallback lib '$DEFAULT_LIB'";
}
# The fallback library was successfully loaded, but the user
# might want to know that we are using the fallback.
if ($param eq 'lib') {
carp "Couldn't load the specified math lib(s) ",
join(", ", map "'$_'", @libs),
", so using fallback lib '$DEFAULT_LIB'";
}
next;
}
# Unrecognized parameter.
push @a, $param;
}
# Any non-':constant' stuff is handled by our parent, Exporter
$class -> SUPER::import(@a); # for subclasses
$class -> export_to_level(1, $class, @a) if @a; # need this, too
# We might not have loaded any backend library yet, either because the user
# didn't specify any, or because the specified libraries failed to load and
# the user allows the use of a fallback library.
unless (defined $LIB) {
eval "require $DEFAULT_LIB";
if ($@) {
croak "No lib specified, and couldn't load the default",
" lib '$DEFAULT_LIB'";
}
$LIB = $DEFAULT_LIB;
}
# import done
}
sub _trailing_zeros {
# return the amount of trailing zeros in $x (as scalar)
my $x = shift;
$x = __PACKAGE__->new($x) unless ref $x;
return 0 if $x->{sign} !~ /^[+-]$/; # NaN, inf, -inf etc
$LIB->_zeros($x->{value}); # must handle odd values, 0 etc
}
sub _scan_for_nonzero {
# internal, used by bround() to scan for non-zeros after a '5'
my ($x, $pad, $xs, $len) = @_;
return 0 if $len == 1; # "5" is trailed by invisible zeros
my $follow = $pad - 1;
return 0 if $follow > $len || $follow < 1;
# use the string form to check whether only '0's follow or not
substr ($xs, -$follow) =~ /[^0]/ ? 1 : 0;
}
sub _find_round_parameters {
# After any operation or when calling round(), the result is rounded by
# regarding the A & P from arguments, local parameters, or globals.
# !!!!!!! If you change this, remember to change round(), too! !!!!!!!!!!
# This procedure finds the round parameters, but it is for speed reasons
# duplicated in round. Otherwise, it is tested by the testsuite and used
# by bdiv().
# returns ($self) or ($self, $a, $p, $r) - sets $self to NaN of both A and P
# were requested/defined (locally or globally or both)
my ($self, $a, $p, $r, @args) = @_;
# $a accuracy, if given by caller
# $p precision, if given by caller
# $r round_mode, if given by caller
# @args all 'other' arguments (0 for unary, 1 for binary ops)
my $class = ref($self); # find out class of argument(s)
# convert to normal scalar for speed and correctness in inner parts
$a = $a->can('numify') ? $a->numify() : "$a" if defined $a && ref($a);
$p = $p->can('numify') ? $p->numify() : "$p" if defined $p && ref($p);
# now pick $a or $p, but only if we have got "arguments"
if (!defined $a) {
foreach ($self, @args) {
# take the defined one, or if both defined, the one that is smaller
$a = $_->{accuracy}
if (defined $_->{accuracy}) && (!defined $a || $_->{accuracy} < $a);
}
}
if (!defined $p) {
# even if $a is defined, take $p, to signal error for both defined
foreach ($self, @args) {
# take the defined one, or if both defined, the one that is bigger
# -2 > -3, and 3 > 2
$p = $_->{precision}
if (defined $_->{precision}) && (!defined $p || $_->{precision} > $p);
}
}
# if still none defined, use globals (#2)
$a = $class -> accuracy() unless defined $a;
$p = $class -> precision() unless defined $p;
# A == 0 is useless, so undef it to signal no rounding
$a = undef if defined $a && $a == 0;
# no rounding today?
return ($self) unless defined $a || defined $p; # early out
# set A and set P is an fatal error
return ($self->bnan()) if defined $a && defined $p; # error
$r = $class -> round_mode() unless defined $r;
if ($r !~ /^(even|odd|[+-]inf|zero|trunc|common)$/) {
croak("Unknown round mode '$r'");
}
$a = int($a) if defined $a;
$p = int($p) if defined $p;
($self, $a, $p, $r);
}
# Return true if the input is numeric and false if it is a string.
sub _is_numeric {
shift; # class name
my $value = shift;
no warnings 'numeric';
# detect numbers
# string & "" -> ""
# number & "" -> 0 (with warning)
# nan and inf can detect as numbers, so check with * 0
return unless CORE::length((my $dummy = "") & $value);
return unless 0 + $value eq $value;
return 1 if $value * 0 == 0;
return -1; # Inf/NaN
}
# Trims the sign of the significand, the (absolute value of the) significand,
# the sign of the exponent, and the (absolute value of the) exponent. The
# returned values have no underscores ("_") or unnecessary leading or trailing
# zeros.
sub _trim_split_parts {
shift; # class name
my $sig_sgn = shift() || '+';
my $sig_str = shift() || '0';
my $exp_sgn = shift() || '+';
my $exp_str = shift() || '0';
$sig_str =~ tr/_//d; # "1.0_0_0" -> "1.000"
$sig_str =~ s/^0+//; # "01.000" -> "1.000"
$sig_str =~ s/\.0*$// # "1.000" -> "1"
|| $sig_str =~ s/(\..*[^0])0+$/$1/; # "1.010" -> "1.01"
$sig_str = '0' unless CORE::length($sig_str);
return '+', '0', '+', '0' if $sig_str eq '0';
$exp_str =~ tr/_//d; # "01_234" -> "01234"
$exp_str =~ s/^0+//; # "01234" -> "1234"
$exp_str = '0' unless CORE::length($exp_str);
$exp_sgn = '+' if $exp_str eq '0'; # "+3e-0" -> "+3e+0"
return $sig_sgn, $sig_str, $exp_sgn, $exp_str;
}
# Takes any string representing a valid decimal number and splits it into four
# strings: the sign of the significand, the absolute value of the significand,
# the sign of the exponent, and the absolute value of the exponent. Both the
# significand and the exponent are in base 10.
#
# Perl accepts literals like the following. The value is 100.1.
#
# 1__0__.__0__1__e+0__1__ (prints "Misplaced _ in number")
# 1_0.0_1e+0_1
#
# Strings representing decimal numbers do not allow underscores, so only the
# following is valid
#
# "10.01e+01"
sub _dec_str_to_dec_str_parts {
my $class = shift;
my $str = shift;
if ($str =~ /
^
# optional leading whitespace
\s*
# optional sign
( [+-]? )
# significand
(
# integer part and optional fraction part ...
\d+ (?: _+ \d+ )* _*
(?:
\.
(?: _* \d+ (?: _+ \d+ )* _* )?
)?
|
# ... or mandatory fraction part
\.
\d+ (?: _+ \d+ )* _*
)
# optional exponent
(?:
[Ee]
( [+-]? )
( \d+ (?: _+ \d+ )* _* )
)?
# optional trailing whitespace
\s*
$
/x)
{
return $class -> _trim_split_parts($1, $2, $3, $4);
}
return;
}
# Takes any string representing a valid hexadecimal number and splits it into
# four strings: the sign of the significand, the absolute value of the
# significand, the sign of the exponent, and the absolute value of the exponent.
# The significand is in base 16, and the exponent is in base 2.
#
# Perl accepts literals like the following. The "x" might be a capital "X". The
# value is 32.0078125.
#
# 0x__1__0__.0__1__p+0__1__ (prints "Misplaced _ in number")
# 0x1_0.0_1p+0_1
#
# The CORE::hex() function does not accept floating point accepts
#
# "0x_1_0"
# "x_1_0"
# "_1_0"
sub _hex_str_to_hex_str_parts {
my $class = shift;
my $str = shift;
if ($str =~ /
^
# optional leading whitespace
\s*
# optional sign
( [+-]? )
# optional hex prefix
(?: 0? [Xx] _* )?
# significand using the hex digits 0..9 and a..f
(
# integer part and optional fraction part ...
[0-9a-fA-F]+ (?: _+ [0-9a-fA-F]+ )* _*
(?:
\.
(?: _* [0-9a-fA-F]+ (?: _+ [0-9a-fA-F]+ )* _* )?
)?
|
# ... or mandatory fraction part
\.
[0-9a-fA-F]+ (?: _+ [0-9a-fA-F]+ )* _*
)
# optional exponent (power of 2) using decimal digits
(?:
[Pp]
( [+-]? )
( \d+ (?: _+ \d+ )* _* )
)?
# optional trailing whitespace
\s*
$
/x)
{
return $class -> _trim_split_parts($1, $2, $3, $4);
}
return;
}
# Takes any string representing a valid octal number and splits it into four
# strings: the sign of the significand, the absolute value of the significand,
# the sign of the exponent, and the absolute value of the exponent. The
# significand is in base 8, and the exponent is in base 2.
sub _oct_str_to_oct_str_parts {
my $class = shift;
my $str = shift;
if ($str =~ /
^
# optional leading whitespace
\s*
# optional sign
( [+-]? )
# optional octal prefix
(?: 0? [Oo] _* )?
# significand using the octal digits 0..7
(
# integer part and optional fraction part ...
[0-7]+ (?: _+ [0-7]+ )* _*
(?:
\.
(?: _* [0-7]+ (?: _+ [0-7]+ )* _* )?
)?
|
# ... or mandatory fraction part
\.
[0-7]+ (?: _+ [0-7]+ )* _*
)
# optional exponent (power of 2) using decimal digits
(?:
[Pp]
( [+-]? )
( \d+ (?: _+ \d+ )* _* )
)?
# optional trailing whitespace
\s*
$
/x)
{
return $class -> _trim_split_parts($1, $2, $3, $4);
}
return;
}
# Takes any string representing a valid binary number and splits it into four
# strings: the sign of the significand, the absolute value of the significand,
# the sign of the exponent, and the absolute value of the exponent. The
# significand is in base 2, and the exponent is in base 2.
sub _bin_str_to_bin_str_parts {
my $class = shift;
my $str = shift;
if ($str =~ /
^
# optional leading whitespace
\s*
# optional sign
( [+-]? )
# optional binary prefix
(?: 0? [Bb] _* )?
# significand using the binary digits 0 and 1
(
# integer part and optional fraction part ...
[01]+ (?: _+ [01]+ )* _*
(?:
\.
(?: _* [01]+ (?: _+ [01]+ )* _* )?
)?
|
# ... or mandatory fraction part
\.
[01]+ (?: _+ [01]+ )* _*
)
# optional exponent (power of 2) using decimal digits
(?:
[Pp]
( [+-]? )
( \d+ (?: _+ \d+ )* _* )
)?
# optional trailing whitespace
\s*
$
/x)
{
return $class -> _trim_split_parts($1, $2, $3, $4);
}
return;
}
# Takes any string representing a valid decimal number and splits it into four
# parts: the sign of the significand, the absolute value of the significand as a
# libray thingy, the sign of the exponent, and the absolute value of the
# exponent as a library thingy.
sub _dec_str_parts_to_flt_lib_parts {
shift; # class name
my ($sig_sgn, $sig_str, $exp_sgn, $exp_str) = @_;
# Handle zero.
if ($sig_str eq '0') {
return '+', $LIB -> _zero(), '+', $LIB -> _zero();
}
# Absolute value of exponent as library "object".
my $exp_lib = $LIB -> _new($exp_str);
# If there is a dot in the significand, remove it so the significand
# becomes an integer and adjust the exponent accordingly. Also remove
# leading zeros which might now appear in the significand. E.g.,
#
# 12.345e-2 -> 12345e-5
# 12.345e+2 -> 12345e-1
# 0.0123e+5 -> 00123e+1 -> 123e+1
my $idx = index $sig_str, '.';
if ($idx >= 0) {
substr($sig_str, $idx, 1) = '';
# delta = length - index
my $delta = $LIB -> _new(CORE::length($sig_str));
$delta = $LIB -> _sub($delta, $LIB -> _new($idx));
# exponent - delta
($exp_lib, $exp_sgn) = $LIB -> _ssub($exp_lib, $exp_sgn, $delta, '+');
$sig_str =~ s/^0+//;
}
# If there are trailing zeros in the significand, remove them and
# adjust the exponent. E.g.,
#
# 12340e-5 -> 1234e-4
# 12340e-1 -> 1234e0
# 12340e+3 -> 1234e4
if ($sig_str =~ s/(0+)\z//) {
my $len = CORE::length($1);
($exp_lib, $exp_sgn) =
$LIB -> _sadd($exp_lib, $exp_sgn, $LIB -> _new($len), '+');
}
# At this point, the significand is empty or an integer with no trailing
# zeros. The exponent is in base 10.
unless (CORE::length $sig_str) {
return '+', $LIB -> _zero(), '+', $LIB -> _zero();
}
# Absolute value of significand as library "object".
my $sig_lib = $LIB -> _new($sig_str);
return $sig_sgn, $sig_lib, $exp_sgn, $exp_lib;
}
# Takes any string representing a valid binary number and splits it into four
# parts: the sign of the significand, the absolute value of the significand as a
# libray thingy, the sign of the exponent, and the absolute value of the
# exponent as a library thingy.
sub _bin_str_parts_to_flt_lib_parts {
shift; # class name
my ($sig_sgn, $sig_str, $exp_sgn, $exp_str, $bpc) = @_;
my $bpc_lib = $LIB -> _new($bpc);
# Handle zero.
if ($sig_str eq '0') {
return '+', $LIB -> _zero(), '+', $LIB -> _zero();
}
# Absolute value of exponent as library "object".
my $exp_lib = $LIB -> _new($exp_str);
# If there is a dot in the significand, remove it so the significand
# becomes an integer and adjust the exponent accordingly. Also remove
# leading zeros which might now appear in the significand. E.g., with
# hexadecimal numbers
#
# 12.345p-2 -> 12345p-14
# 12.345p+2 -> 12345p-10
# 0.0123p+5 -> 00123p-11 -> 123p-11
my $idx = index $sig_str, '.';
if ($idx >= 0) {
substr($sig_str, $idx, 1) = '';
# delta = (length - index) * bpc
my $delta = $LIB -> _new(CORE::length($sig_str));
$delta = $LIB -> _sub($delta, $LIB -> _new($idx));
$delta = $LIB -> _mul($delta, $bpc_lib) if $bpc != 1;
# exponent - delta
($exp_lib, $exp_sgn) = $LIB -> _ssub($exp_lib, $exp_sgn, $delta, '+');
$sig_str =~ s/^0+//;
}
# If there are trailing zeros in the significand, remove them and
# adjust the exponent accordingly. E.g., with hexadecimal numbers
#
# 12340p-5 -> 1234p-1
# 12340p-1 -> 1234p+3
# 12340p+3 -> 1234p+7
if ($sig_str =~ s/(0+)\z//) {
# delta = length * bpc
my $delta = $LIB -> _new(CORE::length($1));
$delta = $LIB -> _mul($delta, $bpc_lib) if $bpc != 1;
# exponent + delta
($exp_lib, $exp_sgn) = $LIB -> _sadd($exp_lib, $exp_sgn, $delta, '+');
}
# At this point, the significand is empty or an integer with no leading
# or trailing zeros. The exponent is in base 2.
unless (CORE::length $sig_str) {
return '+', $LIB -> _zero(), '+', $LIB -> _zero();
}
# Absolute value of significand as library "object".
my $sig_lib = $bpc == 1 ? $LIB -> _from_bin('0b' . $sig_str)
: $bpc == 3 ? $LIB -> _from_oct('0' . $sig_str)
: $bpc == 4 ? $LIB -> _from_hex('0x' . $sig_str)
: die "internal error: invalid exponent multiplier";
# If the exponent (in base 2) is positive or zero ...
if ($exp_sgn eq '+') {
if (!$LIB -> _is_zero($exp_lib)) {
# Multiply significand by 2 raised to the exponent.
my $p = $LIB -> _pow($LIB -> _two(), $exp_lib);
$sig_lib = $LIB -> _mul($sig_lib, $p);
$exp_lib = $LIB -> _zero();
}
}
# ... else if the exponent is negative ...
else {
# Rather than dividing the significand by 2 raised to the absolute
# value of the exponent, multiply the significand by 5 raised to the
# absolute value of the exponent and let the exponent be in base 10:
#
# a * 2^(-b) = a * 5^b * 10^(-b) = c * 10^(-b), where c = a * 5^b
my $p = $LIB -> _pow($LIB -> _new("5"), $exp_lib);
$sig_lib = $LIB -> _mul($sig_lib, $p);
}
# Adjust for the case when the conversion to decimal introduced trailing
# zeros in the significand.
my $n = $LIB -> _zeros($sig_lib);
if ($n) {
$n = $LIB -> _new($n);
$sig_lib = $LIB -> _rsft($sig_lib, $n, 10);
($exp_lib, $exp_sgn) = $LIB -> _sadd($exp_lib, $exp_sgn, $n, '+');
}
return $sig_sgn, $sig_lib, $exp_sgn, $exp_lib;
}
# Takes any string representing a valid hexadecimal number and splits it into
# four parts: the sign of the significand, the absolute value of the significand
# as a libray thingy, the sign of the exponent, and the absolute value of the
# exponent as a library thingy.
sub _hex_str_to_flt_lib_parts {
my $class = shift;
my $str = shift;
if (my @parts = $class -> _hex_str_to_hex_str_parts($str)) {
return $class -> _bin_str_parts_to_flt_lib_parts(@parts, 4); # 4 bits pr. chr
}
return;
}
# Takes any string representing a valid octal number and splits it into four
# parts: the sign of the significand, the absolute value of the significand as a
# libray thingy, the sign of the exponent, and the absolute value of the
# exponent as a library thingy.
sub _oct_str_to_flt_lib_parts {
my $class = shift;
my $str = shift;
if (my @parts = $class -> _oct_str_to_oct_str_parts($str)) {
return $class -> _bin_str_parts_to_flt_lib_parts(@parts, 3); # 3 bits pr. chr
}
return;
}
# Takes any string representing a valid binary number and splits it into four
# parts: the sign of the significand, the absolute value of the significand as a
# libray thingy, the sign of the exponent, and the absolute value of the
# exponent as a library thingy.
sub _bin_str_to_flt_lib_parts {
my $class = shift;
my $str = shift;
if (my @parts = $class -> _bin_str_to_bin_str_parts($str)) {
return $class -> _bin_str_parts_to_flt_lib_parts(@parts, 1); # 1 bit pr. chr
}
return;
}
# Decimal string is split into the sign of the signficant, the absolute value of
# the significand as library thingy, the sign of the exponent, and the absolute
# value of the exponent as a a library thingy.
sub _dec_str_to_flt_lib_parts {
my $class = shift;
my $str = shift;
if (my @parts = $class -> _dec_str_to_dec_str_parts($str)) {
return $class -> _dec_str_parts_to_flt_lib_parts(@parts);
}
return;
}
# Hexdecimal string to a string using decimal floating point notation.
sub hex_str_to_dec_flt_str {
my $class = shift;
my $str = shift;
if (my @parts = $class -> _hex_str_to_flt_lib_parts($str)) {
return $class -> _flt_lib_parts_to_flt_str(@parts);
}
return;
}
# Octal string to a string using decimal floating point notation.
sub oct_str_to_dec_flt_str {
my $class = shift;
my $str = shift;
if (my @parts = $class -> _oct_str_to_flt_lib_parts($str)) {
return $class -> _flt_lib_parts_to_flt_str(@parts);
}
return;
}
# Binary string to a string decimal floating point notation.
sub bin_str_to_dec_flt_str {
my $class = shift;
my $str = shift;
if (my @parts = $class -> _bin_str_to_flt_lib_parts($str)) {
return $class -> _flt_lib_parts_to_flt_str(@parts);
}
return;
}
# Decimal string to a string using decimal floating point notation.
sub dec_str_to_dec_flt_str {
my $class = shift;
my $str = shift;
if (my @parts = $class -> _dec_str_to_flt_lib_parts($str)) {
return $class -> _flt_lib_parts_to_flt_str(@parts);
}
return;
}
# Hexdecimal string to decimal notation (no exponent).
sub hex_str_to_dec_str {
my $class = shift;
my $str = shift;
if (my @parts = $class -> _dec_str_to_flt_lib_parts($str)) {
return $class -> _flt_lib_parts_to_dec_str(@parts);
}
return;
}
# Octal string to decimal notation (no exponent).
sub oct_str_to_dec_str {
my $class = shift;
my $str = shift;
if (my @parts = $class -> _oct_str_to_flt_lib_parts($str)) {
return $class -> _flt_lib_parts_to_dec_str(@parts);
}
return;
}
# Binary string to decimal notation (no exponent).
sub bin_str_to_dec_str {
my $class = shift;
my $str = shift;
if (my @parts = $class -> _bin_str_to_flt_lib_parts($str)) {
return $class -> _flt_lib_parts_to_dec_str(@parts);
}
return;
}
# Decimal string to decimal notation (no exponent).
sub dec_str_to_dec_str {
my $class = shift;
my $str = shift;
if (my @parts = $class -> _dec_str_to_flt_lib_parts($str)) {
return $class -> _flt_lib_parts_to_dec_str(@parts);
}
return;
}
sub _flt_lib_parts_to_flt_str {
my $class = shift;
my @parts = @_;
return $parts[0] . $LIB -> _str($parts[1])
. 'e' . $parts[2] . $LIB -> _str($parts[3]);
}
sub _flt_lib_parts_to_dec_str {
my $class = shift;
my @parts = @_;
# The number is an integer iff the exponent is non-negative.
if ($parts[2] eq '+') {
my $str = $parts[0]
. $LIB -> _str($LIB -> _lsft($parts[1], $parts[3], 10));
return $str;
}
# If it is not an integer, add a decimal point.
else {
my $mant = $LIB -> _str($parts[1]);
my $mant_len = CORE::length($mant);
my $expo = $LIB -> _num($parts[3]);
my $len_cmp = $mant_len <=> $expo;
if ($len_cmp <= 0) {
return $parts[0] . '0.' . '0' x ($expo - $mant_len) . $mant;
} else {
substr $mant, $mant_len - $expo, 0, '.';
return $parts[0] . $mant;
}
}
}
# Takes four arguments, the sign of the significand, the absolute value of the
# significand as a libray thingy, the sign of the exponent, and the absolute
# value of the exponent as a library thingy, and returns three parts: the sign
# of the rational number, the absolute value of the numerator as a libray
# thingy, and the absolute value of the denominator as a library thingy.
#
# For example, to convert data representing the value "+12e-2", then
#
# $sm = "+";
# $m = $LIB -> _new("12");
# $se = "-";
# $e = $LIB -> _new("2");
# ($sr, $n, $d) = $class -> _flt_lib_parts_to_rat_lib_parts($sm, $m, $se, $e);
#
# returns data representing the same value written as the fraction "+3/25"
#
# $sr = "+"
# $n = $LIB -> _new("3");
# $d = $LIB -> _new("12");
sub _flt_lib_parts_to_rat_lib_parts {
my $self = shift;
my ($msgn, $mabs, $esgn, $eabs) = @_;
if ($esgn eq '-') { # "12e-2" -> "12/100" -> "3/25"
my $num_lib = $LIB -> _copy($mabs);
my $den_lib = $LIB -> _1ex($LIB -> _num($eabs));
my $gcd_lib = $LIB -> _gcd($LIB -> _copy($num_lib), $den_lib);
$num_lib = $LIB -> _div($LIB -> _copy($num_lib), $gcd_lib);
$den_lib = $LIB -> _div($den_lib, $gcd_lib);
return $msgn, $num_lib, $den_lib;
}
elsif (!$LIB -> _is_zero($eabs)) { # "12e+2" -> "1200" -> "1200/1"
return $msgn, $LIB -> _lsft($LIB -> _copy($mabs), $eabs, 10),
$LIB -> _one();
}
else { # "12e+0" -> "12" -> "12/1"
return $msgn, $mabs, $LIB -> _one();
}
}
# Add the function _register_callback() to Math::BigInt. It is provided for
# backwards compabibility so that old version of Math::BigRat etc. don't
# complain about missing it.
sub _register_callback { }
###############################################################################
# this method returns 0 if the object can be modified, or 1 if not.
# We use a fast constant sub() here, to avoid costly calls. Subclasses
# may override it with special code (f.i. Math::BigInt::Constant does so)
sub modify () { 0; }
1;
__END__
=pod
=head1 NAME
Math::BigInt - arbitrary size integer math package
=head1 SYNOPSIS
use Math::BigInt;
# or make it faster with huge numbers: install (optional)
# Math::BigInt::GMP and always use (it falls back to
# pure Perl if the GMP library is not installed):
# (See also the L for more information.
For more benchmark results see L.
=head1 SUBCLASSING
=head2 Subclassing Math::BigInt
The basic design of Math::BigInt allows simple subclasses with very little
work, as long as a few simple rules are followed:
=over
=item *
The public API must remain consistent, i.e. if a sub-class is overloading
addition, the sub-class must use the same name, in this case badd(). The reason
for this is that Math::BigInt is optimized to call the object methods directly.
=item *
The private object hash keys like C<< $x->{sign} >> may not be changed, but
additional keys can be added, like C<< $x->{_custom} >>.
=item *
Accessor functions are available for all existing object hash keys and should
be used instead of directly accessing the internal hash keys. The reason for
this is that Math::BigInt itself has a pluggable interface which permits it to
support different storage methods.
=back
More complex sub-classes may have to replicate more of the logic internal of
Math::BigInt if they need to change more basic behaviors. A subclass that needs
to merely change the output only needs to overload C.
All other object methods and overloaded functions can be directly inherited
from the parent class.
At the very minimum, any subclass needs to provide its own C and can
store additional hash keys in the object. There are also some package globals
that must be defined, e.g.:
# Globals
our $accuracy = 2; # round to 2 decimal places
our $precision = undef;
our $round_mode = 'even';
our $div_scale = 40;
Additionally, you might want to provide the following two globals to allow
auto-upgrading and auto-downgrading:
our $upgrade = undef;
our $downgrade = undef;
This allows Math::BigInt to correctly retrieve package globals from the
subclass, like C<$SubClass::precision>. See C,
C, or C for subclass
examples.
Don't forget to
use overload;
in your subclass to automatically inherit the overloading from the parent. If
you like, you can change part of the overloading, look at Math::String for an
example.
=head1 UPGRADING
When used like this:
use Math::BigInt upgrade => 'Foo::Bar';
any operation whose result cannot be represented as an integer is upgraded to
the class Foo::Bar. Usually this is used in conjunction with Math::BigFloat:
use Math::BigInt upgrade => 'Math::BigFloat';
For example, the following returns 3 as a Math::BigInt when no upgrading is
defined, and 3.125 as a Math::BigFloat if Math::BigInt is set to upgrade to
Math::BigFloat:
$x = Math::BigInt -> new(25) -> bdiv(8);
As a shortcut, you can use the module L:
use bignum;
which is also good for one-liners:
perl -Mbignum -le 'print 2 ** 255'
This makes it possible to mix arguments of different classes (as in 2.5 + 2) as
well es preserve accuracy (as in sqrt(3)).
Beware: This feature is not fully implemented yet.
=head2 Auto-upgrade
The following methods upgrade themselves unconditionally; that is if upgrade is
in effect, they always hands up their work:
div bsqrt blog bexp bpi bsin bcos batan batan2
All other methods upgrade themselves only when one (or all) of their arguments
are of the class mentioned in $upgrade.
=head1 EXPORTS
C exports nothing by default, but can export the following
methods:
bgcd
blcm
=head1 CAVEATS
Some things might not work as you expect them. Below is documented what is
known to be troublesome:
=over
=item Comparing numbers as strings
Both C and C as well as stringify via overload drop the
leading '+'. This is to be consistent with Perl and to make C (especially
with overloading) to work as you expect. It also solves problems with
C and L, which stringify arguments before comparing them.
Mark Biggar said, when asked about to drop the '+' altogether, or make only
C work:
I agree (with the first alternative), don't add the '+' on positive
numbers. It's not as important anymore with the new internal form
for numbers. It made doing things like abs and neg easier, but
those have to be done differently now anyway.
So, the following examples now works as expected:
use Test::More tests => 1;
use Math::BigInt;
my $x = Math::BigInt -> new(3*3);
my $y = Math::BigInt -> new(3*3);
is($x,3*3, 'multiplication');
print "$x eq 9" if $x eq $y;
print "$x eq 9" if $x eq '9';
print "$x eq 9" if $x eq 3*3;
Additionally, the following still works:
print "$x == 9" if $x == $y;
print "$x == 9" if $x == 9;
print "$x == 9" if $x == 3*3;
There is now a C method to get the string in scientific notation aka
C<1e+2> instead of C<100>. Be advised that overloaded 'eq' always uses bstr()
for comparison, but Perl represents some numbers as 100 and others as 1e+308.
If in doubt, convert both arguments to Math::BigInt before comparing them as
strings:
use Test::More tests => 3;
use Math::BigInt;
$x = Math::BigInt->new('1e56');
$y = 1e56;
is($x,$y); # fails
is($x->bsstr(), $y); # okay
$y = Math::BigInt->new($y);
is($x, $y); # okay
Alternatively, simply use C<< <=> >> for comparisons, this always gets it
right. There is not yet a way to get a number automatically represented as a
string that matches exactly the way Perl represents it.
See also the section about L for problems in
comparing NaNs.
=item int()
C returns (at least for Perl v5.7.1 and up) another Math::BigInt, not a
Perl scalar:
$x = Math::BigInt->new(123);
$y = int($x); # 123 as a Math::BigInt
$x = Math::BigFloat->new(123.45);
$y = int($x); # 123 as a Math::BigFloat
If you want a real Perl scalar, use C:
$y = $x->numify(); # 123 as a scalar
This is seldom necessary, though, because this is done automatically, like when
you access an array:
$z = $array[$x]; # does work automatically
=item Modifying and =
Beware of:
$x = Math::BigFloat->new(5);
$y = $x;
This makes a second reference to the B object and stores it in $y. Thus
anything that modifies $x (except overloaded operators) also modifies $y, and
vice versa. Or in other words, C<=> is only safe if you modify your
Math::BigInt objects only via overloaded math. As soon as you use a method call
it breaks:
$x->bmul(2);
print "$x, $y\n"; # prints '10, 10'
If you want a true copy of $x, use:
$y = $x->copy();
You can also chain the calls like this, this first makes a copy and then
multiply it by 2:
$y = $x->copy()->bmul(2);
See also the documentation for overload.pm regarding C<=>.
=item Overloading -$x
The following:
$x = -$x;
is slower than
$x->bneg();
since overload calls C instead of C. The first variant
needs to preserve $x since it does not know that it later gets overwritten.
This makes a copy of $x and takes O(N), but $x->bneg() is O(1).
=item Mixing different object types
With overloaded operators, it is the first (dominating) operand that determines
which method is called. Here are some examples showing what actually gets
called in various cases.
use Math::BigInt;
use Math::BigFloat;
$mbf = Math::BigFloat->new(5);
$mbi2 = Math::BigInt->new(5);
$mbi = Math::BigInt->new(2);
# what actually gets called:
$float = $mbf + $mbi; # $mbf->badd($mbi)
$float = $mbf / $mbi; # $mbf->bdiv($mbi)
$integer = $mbi + $mbf; # $mbi->badd($mbf)
$integer = $mbi2 / $mbi; # $mbi2->bdiv($mbi)
$integer = $mbi2 / $mbf; # $mbi2->bdiv($mbf)
For instance, Math::BigInt->bdiv() always returns a Math::BigInt, regardless of
whether the second operant is a Math::BigFloat. To get a Math::BigFloat you
either need to call the operation manually, make sure each operand already is a
Math::BigFloat, or cast to that type via Math::BigFloat->new():
$float = Math::BigFloat->new($mbi2) / $mbi; # = 2.5
Beware of casting the entire expression, as this would cast the
result, at which point it is too late:
$float = Math::BigFloat->new($mbi2 / $mbi); # = 2
Beware also of the order of more complicated expressions like:
$integer = ($mbi2 + $mbi) / $mbf; # int / float => int
$integer = $mbi2 / Math::BigFloat->new($mbi); # ditto
If in doubt, break the expression into simpler terms, or cast all operands
to the desired resulting type.
Scalar values are a bit different, since:
$float = 2 + $mbf;
$float = $mbf + 2;
both result in the proper type due to the way the overloaded math works.
This section also applies to other overloaded math packages, like Math::String.
One solution to you problem might be autoupgrading|upgrading. See the
pragmas L, L and L for an easy way to do this.
=back
=head1 BUGS
Please report any bugs or feature requests to
C, or through the web interface at
L (requires login).
We will be notified, and then you'll automatically be notified of progress on
your bug as I make changes.
=head1 SUPPORT
You can find documentation for this module with the perldoc command.
perldoc Math::BigInt
You can also look for information at:
=over 4
=item * GitHub
L
=item * RT: CPAN's request tracker
L
=item * MetaCPAN
L
=item * CPAN Testers Matrix
L
=back
=head1 LICENSE
This program is free software; you may redistribute it and/or modify it under
the same terms as Perl itself.
=head1 SEE ALSO
L and L as well as the backend libraries
L, L, and L,
L, and L.
The pragmas L, L, and L might also be of interest. In
addition there is the L pragma which does upgrading and downgrading.
=head1 AUTHORS
=over 4
=item *
Mark Biggar, overloaded interface by Ilya Zakharevich, 1996-2001.
=item *
Completely rewritten by Tels L, 2001-2008.
=item *
Florian Ragwitz Eflora@cpan.orgE, 2010.
=item *
Peter John Acklam Epjacklam@gmail.comE, 2011-.
=back
Many people contributed in one or more ways to the final beast, see the file
CREDITS for an (incomplete) list. If you miss your name, please drop me a
mail. Thank you!
=cut