4 # "Mike had an infinite amount to do and a negative amount of time in which
5 # to do it." - Before and After
8 # The following hash values are used:
9 # value: unsigned int with actual value (as a Math::BigInt::Calc or similiar)
10 # sign : +,-,NaN,+inf,-inf
13 # _f : flags, used by MBF to flag parts of a float as untouchable
15 # Remember not to take shortcuts ala $xs = $x->{value}; $CALC->foo($xs); since
16 # underlying lib might change the reference!
18 my $class = "Math::BigInt";
24 @EXPORT_OK = qw(objectify bgcd blcm);
26 # _trap_inf and _trap_nan are internal and should never be accessed from the
28 use vars qw/$round_mode $accuracy $precision $div_scale $rnd_mode
29 $upgrade $downgrade $_trap_nan $_trap_inf/;
32 # Inside overload, the first arg is always an object. If the original code had
33 # it reversed (like $x = 2 * $y), then the third paramater is true.
34 # In some cases (like add, $x = $x + 2 is the same as $x = 2 + $x) this makes
35 # no difference, but in some cases it does.
37 # For overloaded ops with only one argument we simple use $_[0]->copy() to
38 # preserve the argument.
40 # Thus inheritance of overload operators becomes possible and transparent for
41 # our subclasses without the need to repeat the entire overload section there.
44 '=' => sub { $_[0]->copy(); },
46 # some shortcuts for speed (assumes that reversed order of arguments is routed
47 # to normal '+' and we thus can always modify first arg. If this is changed,
48 # this breaks and must be adjusted.)
49 '+=' => sub { $_[0]->badd($_[1]); },
50 '-=' => sub { $_[0]->bsub($_[1]); },
51 '*=' => sub { $_[0]->bmul($_[1]); },
52 '/=' => sub { scalar $_[0]->bdiv($_[1]); },
53 '%=' => sub { $_[0]->bmod($_[1]); },
54 '^=' => sub { $_[0]->bxor($_[1]); },
55 '&=' => sub { $_[0]->band($_[1]); },
56 '|=' => sub { $_[0]->bior($_[1]); },
58 '**=' => sub { $_[0]->bpow($_[1]); },
59 '<<=' => sub { $_[0]->blsft($_[1]); },
60 '>>=' => sub { $_[0]->brsft($_[1]); },
62 # not supported by Perl yet
63 '..' => \&_pointpoint,
65 '<=>' => sub { my $rc = $_[2] ?
66 ref($_[0])->bcmp($_[1],$_[0]) :
68 $rc = 1 unless defined $rc;
71 # we need '>=' to get things like "1 >= NaN" right:
72 '>=' => sub { my $rc = $_[2] ?
73 ref($_[0])->bcmp($_[1],$_[0]) :
75 # if there was a NaN involved, return false
76 return '' unless defined $rc;
81 "$_[1]" cmp $_[0]->bstr() :
82 $_[0]->bstr() cmp "$_[1]" },
84 # make cos()/sin()/atan2() "work" with BigInt's or subclasses
85 'cos' => sub { cos($_[0]->numify()) },
86 'sin' => sub { sin($_[0]->numify()) },
87 'atan2' => sub { $_[2] ?
88 atan2($_[1],$_[0]->numify()) :
89 atan2($_[0]->numify(),$_[1]) },
91 # are not yet overloadable
92 #'hex' => sub { print "hex"; $_[0]; },
93 #'oct' => sub { print "oct"; $_[0]; },
95 # log(N) is log(N, e), where e is Euler's number
96 'log' => sub { $_[0]->copy()->blog($_[1], undef); },
97 'exp' => sub { $_[0]->copy()->bexp($_[1]); },
98 'int' => sub { $_[0]->copy(); },
99 'neg' => sub { $_[0]->copy()->bneg(); },
100 'abs' => sub { $_[0]->copy()->babs(); },
101 'sqrt' => sub { $_[0]->copy()->bsqrt(); },
102 '~' => sub { $_[0]->copy()->bnot(); },
104 # for subtract it's a bit tricky to not modify b: b-a => -a+b
105 '-' => sub { my $c = $_[0]->copy; $_[2] ?
106 $c->bneg()->badd( $_[1]) :
108 '+' => sub { $_[0]->copy()->badd($_[1]); },
109 '*' => sub { $_[0]->copy()->bmul($_[1]); },
112 $_[2] ? ref($_[0])->new($_[1])->bdiv($_[0]) : $_[0]->copy->bdiv($_[1]);
115 $_[2] ? ref($_[0])->new($_[1])->bmod($_[0]) : $_[0]->copy->bmod($_[1]);
118 $_[2] ? ref($_[0])->new($_[1])->bpow($_[0]) : $_[0]->copy->bpow($_[1]);
121 $_[2] ? ref($_[0])->new($_[1])->blsft($_[0]) : $_[0]->copy->blsft($_[1]);
124 $_[2] ? ref($_[0])->new($_[1])->brsft($_[0]) : $_[0]->copy->brsft($_[1]);
127 $_[2] ? ref($_[0])->new($_[1])->band($_[0]) : $_[0]->copy->band($_[1]);
130 $_[2] ? ref($_[0])->new($_[1])->bior($_[0]) : $_[0]->copy->bior($_[1]);
133 $_[2] ? ref($_[0])->new($_[1])->bxor($_[0]) : $_[0]->copy->bxor($_[1]);
136 # can modify arg of ++ and --, so avoid a copy() for speed, but don't
137 # use $_[0]->bone(), it would modify $_[0] to be 1!
138 '++' => sub { $_[0]->binc() },
139 '--' => sub { $_[0]->bdec() },
141 # if overloaded, O(1) instead of O(N) and twice as fast for small numbers
143 # this kludge is needed for perl prior 5.6.0 since returning 0 here fails :-/
144 # v5.6.1 dumps on this: return !$_[0]->is_zero() || undef; :-(
146 $t = 1 if !$_[0]->is_zero();
150 # the original qw() does not work with the TIESCALAR below, why?
151 # Order of arguments unsignificant
152 '""' => sub { $_[0]->bstr(); },
153 '0+' => sub { $_[0]->numify(); }
156 ##############################################################################
157 # global constants, flags and accessory
159 # These vars are public, but their direct usage is not recommended, use the
160 # accessor methods instead
162 $round_mode = 'even'; # one of 'even', 'odd', '+inf', '-inf', 'zero', 'trunc' or 'common'
167 $upgrade = undef; # default is no upgrade
168 $downgrade = undef; # default is no downgrade
170 # These are internally, and not to be used from the outside at all
172 $_trap_nan = 0; # are NaNs ok? set w/ config()
173 $_trap_inf = 0; # are infs ok? set w/ config()
174 my $nan = 'NaN'; # constants for easier life
176 my $CALC = 'Math::BigInt::FastCalc'; # module to do the low level math
177 # default is FastCalc.pm
178 my $IMPORT = 0; # was import() called yet?
179 # used to make require work
180 my %WARN; # warn only once for low-level libs
181 my %CAN; # cache for $CALC->can(...)
182 my %CALLBACKS; # callbacks to notify on lib loads
183 my $EMU_LIB = 'Math/BigInt/CalcEmu.pm'; # emulate low-level math
185 ##############################################################################
186 # the old code had $rnd_mode, so we need to support it, too
189 sub TIESCALAR { my ($class) = @_; bless \$round_mode, $class; }
190 sub FETCH { return $round_mode; }
191 sub STORE { $rnd_mode = $_[0]->round_mode($_[1]); }
195 # tie to enable $rnd_mode to work transparently
196 tie $rnd_mode, 'Math::BigInt';
198 # set up some handy alias names
199 *as_int = \&as_number;
200 *is_pos = \&is_positive;
201 *is_neg = \&is_negative;
204 ##############################################################################
209 # make Class->round_mode() work
211 my $class = ref($self) || $self || __PACKAGE__;
215 if ($m !~ /^(even|odd|\+inf|\-inf|zero|trunc|common)$/)
217 require Carp; Carp::croak ("Unknown round mode '$m'");
219 return ${"${class}::round_mode"} = $m;
221 ${"${class}::round_mode"};
227 # make Class->upgrade() work
229 my $class = ref($self) || $self || __PACKAGE__;
230 # need to set new value?
233 return ${"${class}::upgrade"} = $_[0];
235 ${"${class}::upgrade"};
241 # make Class->downgrade() work
243 my $class = ref($self) || $self || __PACKAGE__;
244 # need to set new value?
247 return ${"${class}::downgrade"} = $_[0];
249 ${"${class}::downgrade"};
255 # make Class->div_scale() work
257 my $class = ref($self) || $self || __PACKAGE__;
262 require Carp; Carp::croak ('div_scale must be greater than zero');
264 ${"${class}::div_scale"} = $_[0];
266 ${"${class}::div_scale"};
271 # $x->accuracy($a); ref($x) $a
272 # $x->accuracy(); ref($x)
273 # Class->accuracy(); class
274 # Class->accuracy($a); class $a
277 my $class = ref($x) || $x || __PACKAGE__;
280 # need to set new value?
284 # convert objects to scalars to avoid deep recursion. If object doesn't
285 # have numify(), then hopefully it will have overloading for int() and
286 # boolean test without wandering into a deep recursion path...
287 $a = $a->numify() if ref($a) && $a->can('numify');
291 # also croak on non-numerical
295 Carp::croak ('Argument to accuracy must be greater than zero');
299 require Carp; Carp::croak ('Argument to accuracy must be an integer');
304 # $object->accuracy() or fallback to global
305 $x->bround($a) if $a; # not for undef, 0
306 $x->{_a} = $a; # set/overwrite, even if not rounded
307 delete $x->{_p}; # clear P
308 $a = ${"${class}::accuracy"} unless defined $a; # proper return value
312 ${"${class}::accuracy"} = $a; # set global A
313 ${"${class}::precision"} = undef; # clear global P
315 return $a; # shortcut
319 # $object->accuracy() or fallback to global
320 $a = $x->{_a} if ref($x);
321 # but don't return global undef, when $x's accuracy is 0!
322 $a = ${"${class}::accuracy"} if !defined $a;
328 # $x->precision($p); ref($x) $p
329 # $x->precision(); ref($x)
330 # Class->precision(); class
331 # Class->precision($p); class $p
334 my $class = ref($x) || $x || __PACKAGE__;
340 # convert objects to scalars to avoid deep recursion. If object doesn't
341 # have numify(), then hopefully it will have overloading for int() and
342 # boolean test without wandering into a deep recursion path...
343 $p = $p->numify() if ref($p) && $p->can('numify');
344 if ((defined $p) && (int($p) != $p))
346 require Carp; Carp::croak ('Argument to precision must be an integer');
350 # $object->precision() or fallback to global
351 $x->bfround($p) if $p; # not for undef, 0
352 $x->{_p} = $p; # set/overwrite, even if not rounded
353 delete $x->{_a}; # clear A
354 $p = ${"${class}::precision"} unless defined $p; # proper return value
358 ${"${class}::precision"} = $p; # set global P
359 ${"${class}::accuracy"} = undef; # clear global A
361 return $p; # shortcut
365 # $object->precision() or fallback to global
366 $p = $x->{_p} if ref($x);
367 # but don't return global undef, when $x's precision is 0!
368 $p = ${"${class}::precision"} if !defined $p;
374 # return (or set) configuration data as hash ref
375 my $class = shift || 'Math::BigInt';
378 if (@_ > 1 || (@_ == 1 && (ref($_[0]) eq 'HASH')))
380 # try to set given options as arguments from hash
383 if (ref($args) ne 'HASH')
387 # these values can be "set"
391 upgrade downgrade precision accuracy round_mode div_scale/
394 $set_args->{$key} = $args->{$key} if exists $args->{$key};
395 delete $args->{$key};
400 Carp::croak ("Illegal key(s) '",
401 join("','",keys %$args),"' passed to $class\->config()");
403 foreach my $key (keys %$set_args)
405 if ($key =~ /^trap_(inf|nan)\z/)
407 ${"${class}::_trap_$1"} = ($set_args->{"trap_$1"} ? 1 : 0);
410 # use a call instead of just setting the $variable to check argument
411 $class->$key($set_args->{$key});
415 # now return actual configuration
419 lib_version => ${"${CALC}::VERSION"},
421 trap_nan => ${"${class}::_trap_nan"},
422 trap_inf => ${"${class}::_trap_inf"},
423 version => ${"${class}::VERSION"},
426 upgrade downgrade precision accuracy round_mode div_scale
429 $cfg->{$key} = ${"${class}::$key"};
431 if (@_ == 1 && (ref($_[0]) ne 'HASH'))
433 # calls of the style config('lib') return just this value
434 return $cfg->{$_[0]};
441 # select accuracy parameter based on precedence,
442 # used by bround() and bfround(), may return undef for scale (means no op)
443 my ($x,$scale,$mode) = @_;
445 $scale = $x->{_a} unless defined $scale;
450 $scale = ${ $class . '::accuracy' } unless defined $scale;
451 $mode = ${ $class . '::round_mode' } unless defined $mode;
458 # select precision parameter based on precedence,
459 # used by bround() and bfround(), may return undef for scale (means no op)
460 my ($x,$scale,$mode) = @_;
462 $scale = $x->{_p} unless defined $scale;
467 $scale = ${ $class . '::precision' } unless defined $scale;
468 $mode = ${ $class . '::round_mode' } unless defined $mode;
473 ##############################################################################
481 # if two arguments, the first one is the class to "swallow" subclasses
489 return unless ref($x); # only for objects
491 my $self = bless {}, $c;
493 $self->{sign} = $x->{sign};
494 $self->{value} = $CALC->_copy($x->{value});
495 $self->{_a} = $x->{_a} if defined $x->{_a};
496 $self->{_p} = $x->{_p} if defined $x->{_p};
502 # create a new BigInt object from a string or another BigInt object.
503 # see hash keys documented at top
505 # the argument could be an object, so avoid ||, && etc on it, this would
506 # cause costly overloaded code to be called. The only allowed ops are
509 my ($class,$wanted,$a,$p,$r) = @_;
511 # avoid numify-calls by not using || on $wanted!
512 return $class->bzero($a,$p) if !defined $wanted; # default to 0
513 return $class->copy($wanted,$a,$p,$r)
514 if ref($wanted) && $wanted->isa($class); # MBI or subclass
516 $class->import() if $IMPORT == 0; # make require work
518 my $self = bless {}, $class;
520 # shortcut for "normal" numbers
521 if ((!ref $wanted) && ($wanted =~ /^([+-]?)[1-9][0-9]*\z/))
523 $self->{sign} = $1 || '+';
525 if ($wanted =~ /^[+-]/)
527 # remove sign without touching wanted to make it work with constants
528 my $t = $wanted; $t =~ s/^[+-]//;
529 $self->{value} = $CALC->_new($t);
533 $self->{value} = $CALC->_new($wanted);
536 if ( (defined $a) || (defined $p)
537 || (defined ${"${class}::precision"})
538 || (defined ${"${class}::accuracy"})
541 $self->round($a,$p,$r) unless (@_ == 4 && !defined $a && !defined $p);
546 # handle '+inf', '-inf' first
547 if ($wanted =~ /^[+-]?inf\z/)
549 $self->{sign} = $wanted; # set a default sign for bstr()
550 return $self->binf($wanted);
552 # split str in m mantissa, e exponent, i integer, f fraction, v value, s sign
553 my ($mis,$miv,$mfv,$es,$ev) = _split($wanted);
558 require Carp; Carp::croak("$wanted is not a number in $class");
560 $self->{value} = $CALC->_zero();
561 $self->{sign} = $nan;
566 # _from_hex or _from_bin
567 $self->{value} = $mis->{value};
568 $self->{sign} = $mis->{sign};
569 return $self; # throw away $mis
571 # make integer from mantissa by adjusting exp, then convert to bigint
572 $self->{sign} = $$mis; # store sign
573 $self->{value} = $CALC->_zero(); # for all the NaN cases
574 my $e = int("$$es$$ev"); # exponent (avoid recursion)
577 my $diff = $e - CORE::length($$mfv);
578 if ($diff < 0) # Not integer
582 require Carp; Carp::croak("$wanted not an integer in $class");
585 return $upgrade->new($wanted,$a,$p,$r) if defined $upgrade;
586 $self->{sign} = $nan;
590 # adjust fraction and add it to value
591 #print "diff > 0 $$miv\n";
592 $$miv = $$miv . ($$mfv . '0' x $diff);
597 if ($$mfv ne '') # e <= 0
599 # fraction and negative/zero E => NOI
602 require Carp; Carp::croak("$wanted not an integer in $class");
604 #print "NOI 2 \$\$mfv '$$mfv'\n";
605 return $upgrade->new($wanted,$a,$p,$r) if defined $upgrade;
606 $self->{sign} = $nan;
610 # xE-y, and empty mfv
613 if ($$miv !~ s/0{$e}$//) # can strip so many zero's?
617 require Carp; Carp::croak("$wanted not an integer in $class");
620 return $upgrade->new($wanted,$a,$p,$r) if defined $upgrade;
621 $self->{sign} = $nan;
625 $self->{sign} = '+' if $$miv eq '0'; # normalize -0 => +0
626 $self->{value} = $CALC->_new($$miv) if $self->{sign} =~ /^[+-]$/;
627 # if any of the globals is set, use them to round and store them inside $self
628 # do not round for new($x,undef,undef) since that is used by MBF to signal
630 $self->round($a,$p,$r) unless @_ == 4 && !defined $a && !defined $p;
636 # create a bigint 'NaN', if given a BigInt, set it to 'NaN'
638 $self = $class if !defined $self;
641 my $c = $self; $self = {}; bless $self, $c;
644 if (${"${class}::_trap_nan"})
647 Carp::croak ("Tried to set $self to NaN in $class\::bnan()");
649 $self->import() if $IMPORT == 0; # make require work
650 return if $self->modify('bnan');
651 if ($self->can('_bnan'))
653 # use subclass to initialize
658 # otherwise do our own thing
659 $self->{value} = $CALC->_zero();
661 $self->{sign} = $nan;
662 delete $self->{_a}; delete $self->{_p}; # rounding NaN is silly
668 # create a bigint '+-inf', if given a BigInt, set it to '+-inf'
669 # the sign is either '+', or if given, used from there
671 my $sign = shift; $sign = '+' if !defined $sign || $sign !~ /^-(inf)?$/;
672 $self = $class if !defined $self;
675 my $c = $self; $self = {}; bless $self, $c;
678 if (${"${class}::_trap_inf"})
681 Carp::croak ("Tried to set $self to +-inf in $class\::binf()");
683 $self->import() if $IMPORT == 0; # make require work
684 return if $self->modify('binf');
685 if ($self->can('_binf'))
687 # use subclass to initialize
692 # otherwise do our own thing
693 $self->{value} = $CALC->_zero();
695 $sign = $sign . 'inf' if $sign !~ /inf$/; # - => -inf
696 $self->{sign} = $sign;
697 ($self->{_a},$self->{_p}) = @_; # take over requested rounding
703 # create a bigint '+0', if given a BigInt, set it to 0
705 $self = __PACKAGE__ if !defined $self;
709 my $c = $self; $self = {}; bless $self, $c;
711 $self->import() if $IMPORT == 0; # make require work
712 return if $self->modify('bzero');
714 if ($self->can('_bzero'))
716 # use subclass to initialize
721 # otherwise do our own thing
722 $self->{value} = $CALC->_zero();
729 # call like: $x->bzero($a,$p,$r,$y);
730 ($self,$self->{_a},$self->{_p}) = $self->_find_round_parameters(@_);
735 if ( (!defined $self->{_a}) || (defined $_[0] && $_[0] > $self->{_a}));
737 if ( (!defined $self->{_p}) || (defined $_[1] && $_[1] > $self->{_p}));
745 # create a bigint '+1' (or -1 if given sign '-'),
746 # if given a BigInt, set it to +1 or -1, respectively
748 my $sign = shift; $sign = '+' if !defined $sign || $sign ne '-';
749 $self = $class if !defined $self;
753 my $c = $self; $self = {}; bless $self, $c;
755 $self->import() if $IMPORT == 0; # make require work
756 return if $self->modify('bone');
758 if ($self->can('_bone'))
760 # use subclass to initialize
765 # otherwise do our own thing
766 $self->{value} = $CALC->_one();
768 $self->{sign} = $sign;
773 # call like: $x->bone($sign,$a,$p,$r,$y);
774 ($self,$self->{_a},$self->{_p}) = $self->_find_round_parameters(@_);
778 # call like: $x->bone($sign,$a,$p,$r);
780 if ( (!defined $self->{_a}) || (defined $_[0] && $_[0] > $self->{_a}));
782 if ( (!defined $self->{_p}) || (defined $_[1] && $_[1] > $self->{_p}));
788 ##############################################################################
789 # string conversation
793 # (ref to BFLOAT or num_str ) return num_str
794 # Convert number from internal format to scientific string format.
795 # internal format is always normalized (no leading zeros, "-0E0" => "+0E0")
796 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
798 if ($x->{sign} !~ /^[+-]$/)
800 return $x->{sign} unless $x->{sign} eq '+inf'; # -inf, NaN
803 my ($m,$e) = $x->parts();
804 #$m->bstr() . 'e+' . $e->bstr(); # e can only be positive in BigInt
805 # 'e+' because E can only be positive in BigInt
806 $m->bstr() . 'e+' . $CALC->_str($e->{value});
811 # make a string from bigint object
812 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
814 if ($x->{sign} !~ /^[+-]$/)
816 return $x->{sign} unless $x->{sign} eq '+inf'; # -inf, NaN
819 my $es = ''; $es = $x->{sign} if $x->{sign} eq '-';
820 $es.$CALC->_str($x->{value});
825 # Make a "normal" scalar from a BigInt object
826 my $x = shift; $x = $class->new($x) unless ref $x;
828 return $x->bstr() if $x->{sign} !~ /^[+-]$/;
829 my $num = $CALC->_num($x->{value});
830 return -$num if $x->{sign} eq '-';
834 ##############################################################################
835 # public stuff (usually prefixed with "b")
839 # return the sign of the number: +/-/-inf/+inf/NaN
840 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
845 sub _find_round_parameters
847 # After any operation or when calling round(), the result is rounded by
848 # regarding the A & P from arguments, local parameters, or globals.
850 # !!!!!!! If you change this, remember to change round(), too! !!!!!!!!!!
852 # This procedure finds the round parameters, but it is for speed reasons
853 # duplicated in round. Otherwise, it is tested by the testsuite and used
856 # returns ($self) or ($self,$a,$p,$r) - sets $self to NaN of both A and P
857 # were requested/defined (locally or globally or both)
859 my ($self,$a,$p,$r,@args) = @_;
860 # $a accuracy, if given by caller
861 # $p precision, if given by caller
862 # $r round_mode, if given by caller
863 # @args all 'other' arguments (0 for unary, 1 for binary ops)
865 my $c = ref($self); # find out class of argument(s)
868 # now pick $a or $p, but only if we have got "arguments"
871 foreach ($self,@args)
873 # take the defined one, or if both defined, the one that is smaller
874 $a = $_->{_a} if (defined $_->{_a}) && (!defined $a || $_->{_a} < $a);
879 # even if $a is defined, take $p, to signal error for both defined
880 foreach ($self,@args)
882 # take the defined one, or if both defined, the one that is bigger
884 $p = $_->{_p} if (defined $_->{_p}) && (!defined $p || $_->{_p} > $p);
887 # if still none defined, use globals (#2)
888 $a = ${"$c\::accuracy"} unless defined $a;
889 $p = ${"$c\::precision"} unless defined $p;
891 # A == 0 is useless, so undef it to signal no rounding
892 $a = undef if defined $a && $a == 0;
895 return ($self) unless defined $a || defined $p; # early out
897 # set A and set P is an fatal error
898 return ($self->bnan()) if defined $a && defined $p; # error
900 $r = ${"$c\::round_mode"} unless defined $r;
901 if ($r !~ /^(even|odd|\+inf|\-inf|zero|trunc|common)$/)
903 require Carp; Carp::croak ("Unknown round mode '$r'");
911 # Round $self according to given parameters, or given second argument's
912 # parameters or global defaults
914 # for speed reasons, _find_round_parameters is embeded here:
916 my ($self,$a,$p,$r,@args) = @_;
917 # $a accuracy, if given by caller
918 # $p precision, if given by caller
919 # $r round_mode, if given by caller
920 # @args all 'other' arguments (0 for unary, 1 for binary ops)
922 my $c = ref($self); # find out class of argument(s)
925 # now pick $a or $p, but only if we have got "arguments"
928 foreach ($self,@args)
930 # take the defined one, or if both defined, the one that is smaller
931 $a = $_->{_a} if (defined $_->{_a}) && (!defined $a || $_->{_a} < $a);
936 # even if $a is defined, take $p, to signal error for both defined
937 foreach ($self,@args)
939 # take the defined one, or if both defined, the one that is bigger
941 $p = $_->{_p} if (defined $_->{_p}) && (!defined $p || $_->{_p} > $p);
944 # if still none defined, use globals (#2)
945 $a = ${"$c\::accuracy"} unless defined $a;
946 $p = ${"$c\::precision"} unless defined $p;
948 # A == 0 is useless, so undef it to signal no rounding
949 $a = undef if defined $a && $a == 0;
952 return $self unless defined $a || defined $p; # early out
954 # set A and set P is an fatal error
955 return $self->bnan() if defined $a && defined $p;
957 $r = ${"$c\::round_mode"} unless defined $r;
958 if ($r !~ /^(even|odd|\+inf|\-inf|zero|trunc|common)$/)
960 require Carp; Carp::croak ("Unknown round mode '$r'");
963 # now round, by calling either fround or ffround:
966 $self->bround($a,$r) if !defined $self->{_a} || $self->{_a} >= $a;
968 else # both can't be undefined due to early out
970 $self->bfround($p,$r) if !defined $self->{_p} || $self->{_p} <= $p;
972 # bround() or bfround() already callled bnorm() if nec.
978 # (numstr or BINT) return BINT
979 # Normalize number -- no-op here
980 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
986 # (BINT or num_str) return BINT
987 # make number absolute, or return absolute BINT from string
988 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
990 return $x if $x->modify('babs');
991 # post-normalized abs for internal use (does nothing for NaN)
992 $x->{sign} =~ s/^-/+/;
998 # (BINT or num_str) return BINT
999 # negate number or make a negated number from string
1000 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1002 return $x if $x->modify('bneg');
1004 # for +0 dont negate (to have always normalized +0). Does nothing for 'NaN'
1005 $x->{sign} =~ tr/+-/-+/ unless ($x->{sign} eq '+' && $CALC->_is_zero($x->{value}));
1011 # Compares 2 values. Returns one of undef, <0, =0, >0. (suitable for sort)
1012 # (BINT or num_str, BINT or num_str) return cond_code
1015 my ($self,$x,$y) = (ref($_[0]),@_);
1017 # objectify is costly, so avoid it
1018 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1020 ($self,$x,$y) = objectify(2,@_);
1023 return $upgrade->bcmp($x,$y) if defined $upgrade &&
1024 ((!$x->isa($self)) || (!$y->isa($self)));
1026 if (($x->{sign} !~ /^[+-]$/) || ($y->{sign} !~ /^[+-]$/))
1028 # handle +-inf and NaN
1029 return undef if (($x->{sign} eq $nan) || ($y->{sign} eq $nan));
1030 return 0 if $x->{sign} eq $y->{sign} && $x->{sign} =~ /^[+-]inf$/;
1031 return +1 if $x->{sign} eq '+inf';
1032 return -1 if $x->{sign} eq '-inf';
1033 return -1 if $y->{sign} eq '+inf';
1036 # check sign for speed first
1037 return 1 if $x->{sign} eq '+' && $y->{sign} eq '-'; # does also 0 <=> -y
1038 return -1 if $x->{sign} eq '-' && $y->{sign} eq '+'; # does also -x <=> 0
1040 # have same sign, so compare absolute values. Don't make tests for zero here
1041 # because it's actually slower than testin in Calc (especially w/ Pari et al)
1043 # post-normalized compare for internal use (honors signs)
1044 if ($x->{sign} eq '+')
1046 # $x and $y both > 0
1047 return $CALC->_acmp($x->{value},$y->{value});
1051 $CALC->_acmp($y->{value},$x->{value}); # swaped acmp (lib returns 0,1,-1)
1056 # Compares 2 values, ignoring their signs.
1057 # Returns one of undef, <0, =0, >0. (suitable for sort)
1058 # (BINT, BINT) return cond_code
1061 my ($self,$x,$y) = (ref($_[0]),@_);
1062 # objectify is costly, so avoid it
1063 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1065 ($self,$x,$y) = objectify(2,@_);
1068 return $upgrade->bacmp($x,$y) if defined $upgrade &&
1069 ((!$x->isa($self)) || (!$y->isa($self)));
1071 if (($x->{sign} !~ /^[+-]$/) || ($y->{sign} !~ /^[+-]$/))
1073 # handle +-inf and NaN
1074 return undef if (($x->{sign} eq $nan) || ($y->{sign} eq $nan));
1075 return 0 if $x->{sign} =~ /^[+-]inf$/ && $y->{sign} =~ /^[+-]inf$/;
1076 return 1 if $x->{sign} =~ /^[+-]inf$/ && $y->{sign} !~ /^[+-]inf$/;
1079 $CALC->_acmp($x->{value},$y->{value}); # lib does only 0,1,-1
1084 # add second arg (BINT or string) to first (BINT) (modifies first)
1085 # return result as BINT
1088 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1089 # objectify is costly, so avoid it
1090 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1092 ($self,$x,$y,@r) = objectify(2,@_);
1095 return $x if $x->modify('badd');
1096 return $upgrade->badd($upgrade->new($x),$upgrade->new($y),@r) if defined $upgrade &&
1097 ((!$x->isa($self)) || (!$y->isa($self)));
1099 $r[3] = $y; # no push!
1100 # inf and NaN handling
1101 if (($x->{sign} !~ /^[+-]$/) || ($y->{sign} !~ /^[+-]$/))
1104 return $x->bnan() if (($x->{sign} eq $nan) || ($y->{sign} eq $nan));
1106 if (($x->{sign} =~ /^[+-]inf$/) && ($y->{sign} =~ /^[+-]inf$/))
1108 # +inf++inf or -inf+-inf => same, rest is NaN
1109 return $x if $x->{sign} eq $y->{sign};
1112 # +-inf + something => +inf
1113 # something +-inf => +-inf
1114 $x->{sign} = $y->{sign}, return $x if $y->{sign} =~ /^[+-]inf$/;
1118 my ($sx, $sy) = ( $x->{sign}, $y->{sign} ); # get signs
1122 $x->{value} = $CALC->_add($x->{value},$y->{value}); # same sign, abs add
1126 my $a = $CALC->_acmp ($y->{value},$x->{value}); # absolute compare
1129 $x->{value} = $CALC->_sub($y->{value},$x->{value},1); # abs sub w/ swap
1134 # speedup, if equal, set result to 0
1135 $x->{value} = $CALC->_zero();
1140 $x->{value} = $CALC->_sub($x->{value}, $y->{value}); # abs sub
1148 # (BINT or num_str, BINT or num_str) return BINT
1149 # subtract second arg from first, modify first
1152 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1154 # objectify is costly, so avoid it
1155 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1157 ($self,$x,$y,@r) = objectify(2,@_);
1160 return $x if $x->modify('bsub');
1162 return $upgrade->new($x)->bsub($upgrade->new($y),@r) if defined $upgrade &&
1163 ((!$x->isa($self)) || (!$y->isa($self)));
1165 return $x->round(@r) if $y->is_zero();
1167 # To correctly handle the lone special case $x->bsub($x), we note the sign
1168 # of $x, then flip the sign from $y, and if the sign of $x did change, too,
1169 # then we caught the special case:
1170 my $xsign = $x->{sign};
1171 $y->{sign} =~ tr/+\-/-+/; # does nothing for NaN
1172 if ($xsign ne $x->{sign})
1174 # special case of $x->bsub($x) results in 0
1175 return $x->bzero(@r) if $xsign =~ /^[+-]$/;
1176 return $x->bnan(); # NaN, -inf, +inf
1178 $x->badd($y,@r); # badd does not leave internal zeros
1179 $y->{sign} =~ tr/+\-/-+/; # refix $y (does nothing for NaN)
1180 $x; # already rounded by badd() or no round nec.
1185 # increment arg by one
1186 my ($self,$x,$a,$p,$r) = ref($_[0]) ? (ref($_[0]),@_) : objectify(1,@_);
1187 return $x if $x->modify('binc');
1189 if ($x->{sign} eq '+')
1191 $x->{value} = $CALC->_inc($x->{value});
1192 return $x->round($a,$p,$r);
1194 elsif ($x->{sign} eq '-')
1196 $x->{value} = $CALC->_dec($x->{value});
1197 $x->{sign} = '+' if $CALC->_is_zero($x->{value}); # -1 +1 => -0 => +0
1198 return $x->round($a,$p,$r);
1200 # inf, nan handling etc
1201 $x->badd($self->bone(),$a,$p,$r); # badd does round
1206 # decrement arg by one
1207 my ($self,$x,@r) = ref($_[0]) ? (ref($_[0]),@_) : objectify(1,@_);
1208 return $x if $x->modify('bdec');
1210 if ($x->{sign} eq '-')
1213 $x->{value} = $CALC->_inc($x->{value});
1217 return $x->badd($self->bone('-'),@r) unless $x->{sign} eq '+'; # inf or NaN
1219 if ($CALC->_is_zero($x->{value}))
1222 $x->{value} = $CALC->_one(); $x->{sign} = '-'; # 0 => -1
1227 $x->{value} = $CALC->_dec($x->{value});
1235 # calculate $x = $a ** $base + $b and return $a (e.g. the log() to base
1239 my ($self,$x,$base,@r) = (undef,@_);
1240 # objectify is costly, so avoid it
1241 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1243 ($self,$x,$base,@r) = objectify(1,ref($x),@_);
1246 return $x if $x->modify('blog');
1248 $base = $self->new($base) if defined $base && !ref $base;
1250 # inf, -inf, NaN, <0 => NaN
1252 if $x->{sign} ne '+' || (defined $base && $base->{sign} ne '+');
1254 return $upgrade->blog($upgrade->new($x),$base,@r) if
1257 # fix for bug #24969:
1258 # the default base is e (Euler's number) which is not an integer
1261 require Math::BigFloat;
1262 my $u = Math::BigFloat->blog(Math::BigFloat->new($x))->as_int();
1263 # modify $x in place
1264 $x->{value} = $u->{value};
1265 $x->{sign} = $u->{sign};
1269 my ($rc,$exact) = $CALC->_log_int($x->{value},$base->{value});
1270 return $x->bnan() unless defined $rc; # not possible to take log?
1277 # Calculate n over k (binomial coefficient or "choose" function) as integer.
1279 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1281 # objectify is costly, so avoid it
1282 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1284 ($self,$x,$y,@r) = objectify(2,@_);
1287 return $x if $x->modify('bnok');
1288 return $x->bnan() if $x->{sign} eq 'NaN' || $y->{sign} eq 'NaN';
1289 return $x->binf() if $x->{sign} eq '+inf';
1291 # k > n or k < 0 => 0
1292 my $cmp = $x->bacmp($y);
1293 return $x->bzero() if $cmp < 0 || $y->{sign} =~ /^-/;
1295 return $x->bone(@r) if $cmp == 0;
1297 if ($CALC->can('_nok'))
1299 $x->{value} = $CALC->_nok($x->{value},$y->{value});
1303 # ( 7 ) 7! 7*6*5 * 4*3*2*1 7 * 6 * 5
1304 # ( - ) = --------- = --------------- = ---------
1305 # ( 3 ) 3! (7-3)! 3*2*1 * 4*3*2*1 3 * 2 * 1
1307 # compute n - k + 2 (so we start with 5 in the example above)
1312 my $r = $z->copy(); $z->binc();
1313 my $d = $self->new(2);
1314 while ($z->bacmp($x) <= 0) # f < x ?
1316 $r->bmul($z); $r->bdiv($d);
1317 $z->binc(); $d->binc();
1319 $x->{value} = $r->{value}; $x->{sign} = '+';
1321 else { $x->bone(); }
1328 # Calculate e ** $x (Euler's number to the power of X), truncated to
1330 my ($self,$x,@r) = ref($_[0]) ? (ref($_[0]),@_) : objectify(1,@_);
1331 return $x if $x->modify('bexp');
1333 # inf, -inf, NaN, <0 => NaN
1334 return $x->bnan() if $x->{sign} eq 'NaN';
1335 return $x->bone() if $x->is_zero();
1336 return $x if $x->{sign} eq '+inf';
1337 return $x->bzero() if $x->{sign} eq '-inf';
1341 # run through Math::BigFloat unless told otherwise
1342 require Math::BigFloat unless defined $upgrade;
1343 local $upgrade = 'Math::BigFloat' unless defined $upgrade;
1344 # calculate result, truncate it to integer
1345 $u = $upgrade->bexp($upgrade->new($x),@r);
1348 if (!defined $upgrade)
1351 # modify $x in place
1352 $x->{value} = $u->{value};
1360 # (BINT or num_str, BINT or num_str) return BINT
1361 # does not modify arguments, but returns new object
1362 # Lowest Common Multiplicator
1364 my $y = shift; my ($x);
1371 $x = $class->new($y);
1376 my $y = shift; $y = $self->new($y) if !ref ($y);
1384 # (BINT or num_str, BINT or num_str) return BINT
1385 # does not modify arguments, but returns new object
1386 # GCD -- Euclids algorithm, variant C (Knuth Vol 3, pg 341 ff)
1389 $y = $class->new($y) if !ref($y);
1391 my $x = $y->copy()->babs(); # keep arguments
1392 return $x->bnan() if $x->{sign} !~ /^[+-]$/; # x NaN?
1396 $y = shift; $y = $self->new($y) if !ref($y);
1397 return $x->bnan() if $y->{sign} !~ /^[+-]$/; # y NaN?
1398 $x->{value} = $CALC->_gcd($x->{value},$y->{value});
1399 last if $CALC->_is_one($x->{value});
1406 # (num_str or BINT) return BINT
1407 # represent ~x as twos-complement number
1408 # we don't need $self, so undef instead of ref($_[0]) make it slightly faster
1409 my ($self,$x,$a,$p,$r) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
1411 return $x if $x->modify('bnot');
1412 $x->binc()->bneg(); # binc already does round
1415 ##############################################################################
1416 # is_foo test routines
1417 # we don't need $self, so undef instead of ref($_[0]) make it slightly faster
1421 # return true if arg (BINT or num_str) is zero (array '+', '0')
1422 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1424 return 0 if $x->{sign} !~ /^\+$/; # -, NaN & +-inf aren't
1425 $CALC->_is_zero($x->{value});
1430 # return true if arg (BINT or num_str) is NaN
1431 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1433 $x->{sign} eq $nan ? 1 : 0;
1438 # return true if arg (BINT or num_str) is +-inf
1439 my ($self,$x,$sign) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
1443 $sign = '[+-]inf' if $sign eq ''; # +- doesn't matter, only that's inf
1444 $sign = "[$1]inf" if $sign =~ /^([+-])(inf)?$/; # extract '+' or '-'
1445 return $x->{sign} =~ /^$sign$/ ? 1 : 0;
1447 $x->{sign} =~ /^[+-]inf$/ ? 1 : 0; # only +-inf is infinity
1452 # return true if arg (BINT or num_str) is +1, or -1 if sign is given
1453 my ($self,$x,$sign) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
1455 $sign = '+' if !defined $sign || $sign ne '-';
1457 return 0 if $x->{sign} ne $sign; # -1 != +1, NaN, +-inf aren't either
1458 $CALC->_is_one($x->{value});
1463 # return true when arg (BINT or num_str) is odd, false for even
1464 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1466 return 0 if $x->{sign} !~ /^[+-]$/; # NaN & +-inf aren't
1467 $CALC->_is_odd($x->{value});
1472 # return true when arg (BINT or num_str) is even, false for odd
1473 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1475 return 0 if $x->{sign} !~ /^[+-]$/; # NaN & +-inf aren't
1476 $CALC->_is_even($x->{value});
1481 # return true when arg (BINT or num_str) is positive (>= 0)
1482 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1484 return 1 if $x->{sign} eq '+inf'; # +inf is positive
1486 # 0+ is neither positive nor negative
1487 ($x->{sign} eq '+' && !$x->is_zero()) ? 1 : 0;
1492 # return true when arg (BINT or num_str) is negative (< 0)
1493 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1495 $x->{sign} =~ /^-/ ? 1 : 0; # -inf is negative, but NaN is not
1500 # return true when arg (BINT or num_str) is an integer
1501 # always true for BigInt, but different for BigFloats
1502 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1504 $x->{sign} =~ /^[+-]$/ ? 1 : 0; # inf/-inf/NaN aren't
1507 ###############################################################################
1511 # multiply two numbers -- stolen from Knuth Vol 2 pg 233
1512 # (BINT or num_str, BINT or num_str) return BINT
1515 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1516 # objectify is costly, so avoid it
1517 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1519 ($self,$x,$y,@r) = objectify(2,@_);
1522 return $x if $x->modify('bmul');
1524 return $x->bnan() if (($x->{sign} eq $nan) || ($y->{sign} eq $nan));
1527 if (($x->{sign} =~ /^[+-]inf$/) || ($y->{sign} =~ /^[+-]inf$/))
1529 return $x->bnan() if $x->is_zero() || $y->is_zero();
1530 # result will always be +-inf:
1531 # +inf * +/+inf => +inf, -inf * -/-inf => +inf
1532 # +inf * -/-inf => -inf, -inf * +/+inf => -inf
1533 return $x->binf() if ($x->{sign} =~ /^\+/ && $y->{sign} =~ /^\+/);
1534 return $x->binf() if ($x->{sign} =~ /^-/ && $y->{sign} =~ /^-/);
1535 return $x->binf('-');
1538 return $upgrade->bmul($x,$upgrade->new($y),@r)
1539 if defined $upgrade && !$y->isa($self);
1541 $r[3] = $y; # no push here
1543 $x->{sign} = $x->{sign} eq $y->{sign} ? '+' : '-'; # +1 * +1 or -1 * -1 => +
1545 $x->{value} = $CALC->_mul($x->{value},$y->{value}); # do actual math
1546 $x->{sign} = '+' if $CALC->_is_zero($x->{value}); # no -0
1553 # helper function that handles +-inf cases for bdiv()/bmod() to reuse code
1554 my ($self,$x,$y) = @_;
1556 # NaN if x == NaN or y == NaN or x==y==0
1557 return wantarray ? ($x->bnan(),$self->bnan()) : $x->bnan()
1558 if (($x->is_nan() || $y->is_nan()) ||
1559 ($x->is_zero() && $y->is_zero()));
1561 # +-inf / +-inf == NaN, reminder also NaN
1562 if (($x->{sign} =~ /^[+-]inf$/) && ($y->{sign} =~ /^[+-]inf$/))
1564 return wantarray ? ($x->bnan(),$self->bnan()) : $x->bnan();
1566 # x / +-inf => 0, remainder x (works even if x == 0)
1567 if ($y->{sign} =~ /^[+-]inf$/)
1569 my $t = $x->copy(); # bzero clobbers up $x
1570 return wantarray ? ($x->bzero(),$t) : $x->bzero()
1573 # 5 / 0 => +inf, -6 / 0 => -inf
1574 # +inf / 0 = inf, inf, and -inf / 0 => -inf, -inf
1575 # exception: -8 / 0 has remainder -8, not 8
1576 # exception: -inf / 0 has remainder -inf, not inf
1579 # +-inf / 0 => special case for -inf
1580 return wantarray ? ($x,$x->copy()) : $x if $x->is_inf();
1581 if (!$x->is_zero() && !$x->is_inf())
1583 my $t = $x->copy(); # binf clobbers up $x
1585 ($x->binf($x->{sign}),$t) : $x->binf($x->{sign})
1589 # last case: +-inf / ordinary number
1591 $sign = '-inf' if substr($x->{sign},0,1) ne $y->{sign};
1593 return wantarray ? ($x,$self->bzero()) : $x;
1598 # (dividend: BINT or num_str, divisor: BINT or num_str) return
1599 # (BINT,BINT) (quo,rem) or BINT (only rem)
1602 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1603 # objectify is costly, so avoid it
1604 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1606 ($self,$x,$y,@r) = objectify(2,@_);
1609 return $x if $x->modify('bdiv');
1611 return $self->_div_inf($x,$y)
1612 if (($x->{sign} !~ /^[+-]$/) || ($y->{sign} !~ /^[+-]$/) || $y->is_zero());
1614 return $upgrade->bdiv($upgrade->new($x),$upgrade->new($y),@r)
1615 if defined $upgrade;
1617 $r[3] = $y; # no push!
1619 # calc new sign and in case $y == +/- 1, return $x
1620 my $xsign = $x->{sign}; # keep
1621 $x->{sign} = ($x->{sign} ne $y->{sign} ? '-' : '+');
1625 my $rem = $self->bzero();
1626 ($x->{value},$rem->{value}) = $CALC->_div($x->{value},$y->{value});
1627 $x->{sign} = '+' if $CALC->_is_zero($x->{value});
1628 $rem->{_a} = $x->{_a};
1629 $rem->{_p} = $x->{_p};
1631 if (! $CALC->_is_zero($rem->{value}))
1633 $rem->{sign} = $y->{sign};
1634 $rem = $y->copy()->bsub($rem) if $xsign ne $y->{sign}; # one of them '-'
1638 $rem->{sign} = '+'; # dont leave -0
1644 $x->{value} = $CALC->_div($x->{value},$y->{value});
1645 $x->{sign} = '+' if $CALC->_is_zero($x->{value});
1650 ###############################################################################
1655 # modulus (or remainder)
1656 # (BINT or num_str, BINT or num_str) return BINT
1659 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1660 # objectify is costly, so avoid it
1661 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1663 ($self,$x,$y,@r) = objectify(2,@_);
1666 return $x if $x->modify('bmod');
1667 $r[3] = $y; # no push!
1668 if (($x->{sign} !~ /^[+-]$/) || ($y->{sign} !~ /^[+-]$/) || $y->is_zero())
1670 my ($d,$r) = $self->_div_inf($x,$y);
1671 $x->{sign} = $r->{sign};
1672 $x->{value} = $r->{value};
1673 return $x->round(@r);
1676 # calc new sign and in case $y == +/- 1, return $x
1677 $x->{value} = $CALC->_mod($x->{value},$y->{value});
1678 if (!$CALC->_is_zero($x->{value}))
1680 $x->{value} = $CALC->_sub($y->{value},$x->{value},1) # $y-$x
1681 if ($x->{sign} ne $y->{sign});
1682 $x->{sign} = $y->{sign};
1686 $x->{sign} = '+'; # dont leave -0
1693 # Modular inverse. given a number which is (hopefully) relatively
1694 # prime to the modulus, calculate its inverse using Euclid's
1695 # alogrithm. If the number is not relatively prime to the modulus
1696 # (i.e. their gcd is not one) then NaN is returned.
1699 my ($self,$x,$y,@r) = (undef,@_);
1700 # objectify is costly, so avoid it
1701 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1703 ($self,$x,$y,@r) = objectify(2,@_);
1706 return $x if $x->modify('bmodinv');
1709 if ($y->{sign} ne '+' # -, NaN, +inf, -inf
1710 || $x->is_zero() # or num == 0
1711 || $x->{sign} !~ /^[+-]$/ # or num NaN, inf, -inf
1714 # put least residue into $x if $x was negative, and thus make it positive
1715 $x->bmod($y) if $x->{sign} eq '-';
1718 ($x->{value},$sign) = $CALC->_modinv($x->{value},$y->{value});
1719 return $x->bnan() if !defined $x->{value}; # in case no GCD found
1720 return $x if !defined $sign; # already real result
1721 $x->{sign} = $sign; # flip/flop see below
1722 $x->bmod($y); # calc real result
1728 # takes a very large number to a very large exponent in a given very
1729 # large modulus, quickly, thanks to binary exponentation. supports
1730 # negative exponents.
1731 my ($self,$num,$exp,$mod,@r) = objectify(3,@_);
1733 return $num if $num->modify('bmodpow');
1735 # check modulus for valid values
1736 return $num->bnan() if ($mod->{sign} ne '+' # NaN, - , -inf, +inf
1737 || $mod->is_zero());
1739 # check exponent for valid values
1740 if ($exp->{sign} =~ /\w/)
1742 # i.e., if it's NaN, +inf, or -inf...
1743 return $num->bnan();
1746 $num->bmodinv ($mod) if ($exp->{sign} eq '-');
1748 # check num for valid values (also NaN if there was no inverse but $exp < 0)
1749 return $num->bnan() if $num->{sign} !~ /^[+-]$/;
1751 # $mod is positive, sign on $exp is ignored, result also positive
1752 $num->{value} = $CALC->_modpow($num->{value},$exp->{value},$mod->{value});
1756 ###############################################################################
1760 # (BINT or num_str, BINT or num_str) return BINT
1761 # compute factorial number from $x, modify $x in place
1762 my ($self,$x,@r) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
1764 return $x if $x->modify('bfac') || $x->{sign} eq '+inf'; # inf => inf
1765 return $x->bnan() if $x->{sign} ne '+'; # NaN, <0 etc => NaN
1767 $x->{value} = $CALC->_fac($x->{value});
1773 # (BINT or num_str, BINT or num_str) return BINT
1774 # compute power of two numbers -- stolen from Knuth Vol 2 pg 233
1775 # modifies first argument
1778 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1779 # objectify is costly, so avoid it
1780 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1782 ($self,$x,$y,@r) = objectify(2,@_);
1785 return $x if $x->modify('bpow');
1787 return $x->bnan() if $x->{sign} eq $nan || $y->{sign} eq $nan;
1790 if (($x->{sign} =~ /^[+-]inf$/) || ($y->{sign} =~ /^[+-]inf$/))
1792 if (($x->{sign} =~ /^[+-]inf$/) && ($y->{sign} =~ /^[+-]inf$/))
1798 if ($x->{sign} =~ /^[+-]inf/)
1801 return $x->bnan() if $y->is_zero();
1802 # -inf ** -1 => 1/inf => 0
1803 return $x->bzero() if $y->is_one('-') && $x->is_negative();
1806 return $x if $x->{sign} eq '+inf';
1808 # -inf ** Y => -inf if Y is odd
1809 return $x if $y->is_odd();
1815 return $x if $x->is_one();
1818 return $x if $x->is_zero() && $y->{sign} =~ /^[+]/;
1821 return $x->binf() if $x->is_zero();
1824 return $x->bnan() if $x->is_one('-') && $y->{sign} =~ /^[-]/;
1827 return $x->bzero() if $x->{sign} eq '-' && $y->{sign} =~ /^[-]/;
1830 return $x->bnan() if $x->{sign} eq '-';
1833 return $x->binf() if $y->{sign} =~ /^[+]/;
1838 return $upgrade->bpow($upgrade->new($x),$y,@r)
1839 if defined $upgrade && (!$y->isa($self) || $y->{sign} eq '-');
1841 $r[3] = $y; # no push!
1843 # cases 0 ** Y, X ** 0, X ** 1, 1 ** Y are handled by Calc or Emu
1846 $new_sign = $y->is_odd() ? '-' : '+' if ($x->{sign} ne '+');
1848 # 0 ** -7 => ( 1 / (0 ** 7)) => 1 / 0 => +inf
1850 if $y->{sign} eq '-' && $x->{sign} eq '+' && $CALC->_is_zero($x->{value});
1851 # 1 ** -y => 1 / (1 ** |y|)
1852 # so do test for negative $y after above's clause
1853 return $x->bnan() if $y->{sign} eq '-' && !$CALC->_is_one($x->{value});
1855 $x->{value} = $CALC->_pow($x->{value},$y->{value});
1856 $x->{sign} = $new_sign;
1857 $x->{sign} = '+' if $CALC->_is_zero($y->{value});
1863 # (BINT or num_str, BINT or num_str) return BINT
1864 # compute x << y, base n, y >= 0
1867 my ($self,$x,$y,$n,@r) = (ref($_[0]),@_);
1868 # objectify is costly, so avoid it
1869 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1871 ($self,$x,$y,$n,@r) = objectify(2,@_);
1874 return $x if $x->modify('blsft');
1875 return $x->bnan() if ($x->{sign} !~ /^[+-]$/ || $y->{sign} !~ /^[+-]$/);
1876 return $x->round(@r) if $y->is_zero();
1878 $n = 2 if !defined $n; return $x->bnan() if $n <= 0 || $y->{sign} eq '-';
1880 $x->{value} = $CALC->_lsft($x->{value},$y->{value},$n);
1886 # (BINT or num_str, BINT or num_str) return BINT
1887 # compute x >> y, base n, y >= 0
1890 my ($self,$x,$y,$n,@r) = (ref($_[0]),@_);
1891 # objectify is costly, so avoid it
1892 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1894 ($self,$x,$y,$n,@r) = objectify(2,@_);
1897 return $x if $x->modify('brsft');
1898 return $x->bnan() if ($x->{sign} !~ /^[+-]$/ || $y->{sign} !~ /^[+-]$/);
1899 return $x->round(@r) if $y->is_zero();
1900 return $x->bzero(@r) if $x->is_zero(); # 0 => 0
1902 $n = 2 if !defined $n; return $x->bnan() if $n <= 0 || $y->{sign} eq '-';
1904 # this only works for negative numbers when shifting in base 2
1905 if (($x->{sign} eq '-') && ($n == 2))
1907 return $x->round(@r) if $x->is_one('-'); # -1 => -1
1910 # although this is O(N*N) in calc (as_bin!) it is O(N) in Pari et al
1911 # but perhaps there is a better emulation for two's complement shift...
1912 # if $y != 1, we must simulate it by doing:
1913 # convert to bin, flip all bits, shift, and be done
1914 $x->binc(); # -3 => -2
1915 my $bin = $x->as_bin();
1916 $bin =~ s/^-0b//; # strip '-0b' prefix
1917 $bin =~ tr/10/01/; # flip bits
1919 if ($y >= CORE::length($bin))
1921 $bin = '0'; # shifting to far right creates -1
1922 # 0, because later increment makes
1923 # that 1, attached '-' makes it '-1'
1924 # because -1 >> x == -1 !
1928 $bin =~ s/.{$y}$//; # cut off at the right side
1929 $bin = '1' . $bin; # extend left side by one dummy '1'
1930 $bin =~ tr/10/01/; # flip bits back
1932 my $res = $self->new('0b'.$bin); # add prefix and convert back
1933 $res->binc(); # remember to increment
1934 $x->{value} = $res->{value}; # take over value
1935 return $x->round(@r); # we are done now, magic, isn't?
1937 # x < 0, n == 2, y == 1
1938 $x->bdec(); # n == 2, but $y == 1: this fixes it
1941 $x->{value} = $CALC->_rsft($x->{value},$y->{value},$n);
1947 #(BINT or num_str, BINT or num_str) return BINT
1951 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1952 # objectify is costly, so avoid it
1953 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1955 ($self,$x,$y,@r) = objectify(2,@_);
1958 return $x if $x->modify('band');
1960 $r[3] = $y; # no push!
1962 return $x->bnan() if ($x->{sign} !~ /^[+-]$/ || $y->{sign} !~ /^[+-]$/);
1964 my $sx = $x->{sign} eq '+' ? 1 : -1;
1965 my $sy = $y->{sign} eq '+' ? 1 : -1;
1967 if ($sx == 1 && $sy == 1)
1969 $x->{value} = $CALC->_and($x->{value},$y->{value});
1970 return $x->round(@r);
1973 if ($CAN{signed_and})
1975 $x->{value} = $CALC->_signed_and($x->{value},$y->{value},$sx,$sy);
1976 return $x->round(@r);
1980 __emu_band($self,$x,$y,$sx,$sy,@r);
1985 #(BINT or num_str, BINT or num_str) return BINT
1989 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1990 # objectify is costly, so avoid it
1991 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1993 ($self,$x,$y,@r) = objectify(2,@_);
1996 return $x if $x->modify('bior');
1997 $r[3] = $y; # no push!
1999 return $x->bnan() if ($x->{sign} !~ /^[+-]$/ || $y->{sign} !~ /^[+-]$/);
2001 my $sx = $x->{sign} eq '+' ? 1 : -1;
2002 my $sy = $y->{sign} eq '+' ? 1 : -1;
2004 # the sign of X follows the sign of X, e.g. sign of Y irrelevant for bior()
2006 # don't use lib for negative values
2007 if ($sx == 1 && $sy == 1)
2009 $x->{value} = $CALC->_or($x->{value},$y->{value});
2010 return $x->round(@r);
2013 # if lib can do negative values, let it handle this
2014 if ($CAN{signed_or})
2016 $x->{value} = $CALC->_signed_or($x->{value},$y->{value},$sx,$sy);
2017 return $x->round(@r);
2021 __emu_bior($self,$x,$y,$sx,$sy,@r);
2026 #(BINT or num_str, BINT or num_str) return BINT
2030 my ($self,$x,$y,@r) = (ref($_[0]),@_);
2031 # objectify is costly, so avoid it
2032 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
2034 ($self,$x,$y,@r) = objectify(2,@_);
2037 return $x if $x->modify('bxor');
2038 $r[3] = $y; # no push!
2040 return $x->bnan() if ($x->{sign} !~ /^[+-]$/ || $y->{sign} !~ /^[+-]$/);
2042 my $sx = $x->{sign} eq '+' ? 1 : -1;
2043 my $sy = $y->{sign} eq '+' ? 1 : -1;
2045 # don't use lib for negative values
2046 if ($sx == 1 && $sy == 1)
2048 $x->{value} = $CALC->_xor($x->{value},$y->{value});
2049 return $x->round(@r);
2052 # if lib can do negative values, let it handle this
2053 if ($CAN{signed_xor})
2055 $x->{value} = $CALC->_signed_xor($x->{value},$y->{value},$sx,$sy);
2056 return $x->round(@r);
2060 __emu_bxor($self,$x,$y,$sx,$sy,@r);
2065 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
2067 my $e = $CALC->_len($x->{value});
2068 wantarray ? ($e,0) : $e;
2073 # return the nth decimal digit, negative values count backward, 0 is right
2074 my ($self,$x,$n) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
2076 $n = $n->numify() if ref($n);
2077 $CALC->_digit($x->{value},$n||0);
2082 # return the amount of trailing zeros in $x (as scalar)
2084 $x = $class->new($x) unless ref $x;
2086 return 0 if $x->{sign} !~ /^[+-]$/; # NaN, inf, -inf etc
2088 $CALC->_zeros($x->{value}); # must handle odd values, 0 etc
2093 # calculate square root of $x
2094 my ($self,$x,@r) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
2096 return $x if $x->modify('bsqrt');
2098 return $x->bnan() if $x->{sign} !~ /^\+/; # -x or -inf or NaN => NaN
2099 return $x if $x->{sign} eq '+inf'; # sqrt(+inf) == inf
2101 return $upgrade->bsqrt($x,@r) if defined $upgrade;
2103 $x->{value} = $CALC->_sqrt($x->{value});
2109 # calculate $y'th root of $x
2112 my ($self,$x,$y,@r) = (ref($_[0]),@_);
2114 $y = $self->new(2) unless defined $y;
2116 # objectify is costly, so avoid it
2117 if ((!ref($x)) || (ref($x) ne ref($y)))
2119 ($self,$x,$y,@r) = objectify(2,$self || $class,@_);
2122 return $x if $x->modify('broot');
2124 # NaN handling: $x ** 1/0, x or y NaN, or y inf/-inf or y == 0
2125 return $x->bnan() if $x->{sign} !~ /^\+/ || $y->is_zero() ||
2126 $y->{sign} !~ /^\+$/;
2128 return $x->round(@r)
2129 if $x->is_zero() || $x->is_one() || $x->is_inf() || $y->is_one();
2131 return $upgrade->new($x)->broot($upgrade->new($y),@r) if defined $upgrade;
2133 $x->{value} = $CALC->_root($x->{value},$y->{value});
2139 # return a copy of the exponent (here always 0, NaN or 1 for $m == 0)
2140 my ($self,$x) = ref($_[0]) ? (ref($_[0]),$_[0]) : objectify(1,@_);
2142 if ($x->{sign} !~ /^[+-]$/)
2144 my $s = $x->{sign}; $s =~ s/^[+-]//; # NaN, -inf,+inf => NaN or inf
2145 return $self->new($s);
2147 return $self->bone() if $x->is_zero();
2149 # 12300 => 2 trailing zeros => exponent is 2
2150 $self->new( $CALC->_zeros($x->{value}) );
2155 # return the mantissa (compatible to Math::BigFloat, e.g. reduced)
2156 my ($self,$x) = ref($_[0]) ? (ref($_[0]),$_[0]) : objectify(1,@_);
2158 if ($x->{sign} !~ /^[+-]$/)
2160 # for NaN, +inf, -inf: keep the sign
2161 return $self->new($x->{sign});
2163 my $m = $x->copy(); delete $m->{_p}; delete $m->{_a};
2165 # that's a bit inefficient:
2166 my $zeros = $CALC->_zeros($m->{value});
2167 $m->brsft($zeros,10) if $zeros != 0;
2173 # return a copy of both the exponent and the mantissa
2174 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
2176 ($x->mantissa(),$x->exponent());
2179 ##############################################################################
2180 # rounding functions
2184 # precision: round to the $Nth digit left (+$n) or right (-$n) from the '.'
2185 # $n == 0 || $n == 1 => round to integer
2186 my $x = shift; my $self = ref($x) || $x; $x = $self->new($x) unless ref $x;
2188 my ($scale,$mode) = $x->_scale_p(@_);
2190 return $x if !defined $scale || $x->modify('bfround'); # no-op
2192 # no-op for BigInts if $n <= 0
2193 $x->bround( $x->length()-$scale, $mode) if $scale > 0;
2195 delete $x->{_a}; # delete to save memory
2196 $x->{_p} = $scale; # store new _p
2200 sub _scan_for_nonzero
2202 # internal, used by bround() to scan for non-zeros after a '5'
2203 my ($x,$pad,$xs,$len) = @_;
2205 return 0 if $len == 1; # "5" is trailed by invisible zeros
2206 my $follow = $pad - 1;
2207 return 0 if $follow > $len || $follow < 1;
2209 # use the string form to check whether only '0's follow or not
2210 substr ($xs,-$follow) =~ /[^0]/ ? 1 : 0;
2215 # Exists to make life easier for switch between MBF and MBI (should we
2216 # autoload fxxx() like MBF does for bxxx()?)
2217 my $x = shift; $x = $class->new($x) unless ref $x;
2223 # accuracy: +$n preserve $n digits from left,
2224 # -$n preserve $n digits from right (f.i. for 0.1234 style in MBF)
2226 # and overwrite the rest with 0's, return normalized number
2227 # do not return $x->bnorm(), but $x
2229 my $x = shift; $x = $class->new($x) unless ref $x;
2230 my ($scale,$mode) = $x->_scale_a(@_);
2231 return $x if !defined $scale || $x->modify('bround'); # no-op
2233 if ($x->is_zero() || $scale == 0)
2235 $x->{_a} = $scale if !defined $x->{_a} || $x->{_a} > $scale; # 3 > 2
2238 return $x if $x->{sign} !~ /^[+-]$/; # inf, NaN
2240 # we have fewer digits than we want to scale to
2241 my $len = $x->length();
2242 # convert $scale to a scalar in case it is an object (put's a limit on the
2243 # number length, but this would already limited by memory constraints), makes
2245 $scale = $scale->numify() if ref ($scale);
2247 # scale < 0, but > -len (not >=!)
2248 if (($scale < 0 && $scale < -$len-1) || ($scale >= $len))
2250 $x->{_a} = $scale if !defined $x->{_a} || $x->{_a} > $scale; # 3 > 2
2254 # count of 0's to pad, from left (+) or right (-): 9 - +6 => 3, or |-6| => 6
2255 my ($pad,$digit_round,$digit_after);
2256 $pad = $len - $scale;
2257 $pad = abs($scale-1) if $scale < 0;
2259 # do not use digit(), it is very costly for binary => decimal
2260 # getting the entire string is also costly, but we need to do it only once
2261 my $xs = $CALC->_str($x->{value});
2264 # pad: 123: 0 => -1, at 1 => -2, at 2 => -3, at 3 => -4
2265 # pad+1: 123: 0 => 0, at 1 => -1, at 2 => -2, at 3 => -3
2266 $digit_round = '0'; $digit_round = substr($xs,$pl,1) if $pad <= $len;
2267 $pl++; $pl ++ if $pad >= $len;
2268 $digit_after = '0'; $digit_after = substr($xs,$pl,1) if $pad > 0;
2270 # in case of 01234 we round down, for 6789 up, and only in case 5 we look
2271 # closer at the remaining digits of the original $x, remember decision
2272 my $round_up = 1; # default round up
2274 ($mode eq 'trunc') || # trunc by round down
2275 ($digit_after =~ /[01234]/) || # round down anyway,
2277 ($digit_after eq '5') && # not 5000...0000
2278 ($x->_scan_for_nonzero($pad,$xs,$len) == 0) &&
2280 ($mode eq 'even') && ($digit_round =~ /[24680]/) ||
2281 ($mode eq 'odd') && ($digit_round =~ /[13579]/) ||
2282 ($mode eq '+inf') && ($x->{sign} eq '-') ||
2283 ($mode eq '-inf') && ($x->{sign} eq '+') ||
2284 ($mode eq 'zero') # round down if zero, sign adjusted below
2286 my $put_back = 0; # not yet modified
2288 if (($pad > 0) && ($pad <= $len))
2290 substr($xs,-$pad,$pad) = '0' x $pad; # replace with '00...'
2291 $put_back = 1; # need to put back
2295 $x->bzero(); # round to '0'
2298 if ($round_up) # what gave test above?
2300 $put_back = 1; # need to put back
2301 $pad = $len, $xs = '0' x $pad if $scale < 0; # tlr: whack 0.51=>1.0
2303 # we modify directly the string variant instead of creating a number and
2304 # adding it, since that is faster (we already have the string)
2305 my $c = 0; $pad ++; # for $pad == $len case
2306 while ($pad <= $len)
2308 $c = substr($xs,-$pad,1) + 1; $c = '0' if $c eq '10';
2309 substr($xs,-$pad,1) = $c; $pad++;
2310 last if $c != 0; # no overflow => early out
2312 $xs = '1'.$xs if $c == 0;
2315 $x->{value} = $CALC->_new($xs) if $put_back == 1; # put back, if needed
2317 $x->{_a} = $scale if $scale >= 0;
2320 $x->{_a} = $len+$scale;
2321 $x->{_a} = 0 if $scale < -$len;
2328 # return integer less or equal then number; no-op since it's already integer
2329 my ($self,$x,@r) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
2336 # return integer greater or equal then number; no-op since it's already int
2337 my ($self,$x,@r) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
2344 # An object might be asked to return itself as bigint on certain overloaded
2345 # operations. This does exactly this, so that sub classes can simple inherit
2346 # it or override with their own integer conversion routine.
2352 # return as hex string, with prefixed 0x
2353 my $x = shift; $x = $class->new($x) if !ref($x);
2355 return $x->bstr() if $x->{sign} !~ /^[+-]$/; # inf, nan etc
2358 $s = $x->{sign} if $x->{sign} eq '-';
2359 $s . $CALC->_as_hex($x->{value});
2364 # return as binary string, with prefixed 0b
2365 my $x = shift; $x = $class->new($x) if !ref($x);
2367 return $x->bstr() if $x->{sign} !~ /^[+-]$/; # inf, nan etc
2369 my $s = ''; $s = $x->{sign} if $x->{sign} eq '-';
2370 return $s . $CALC->_as_bin($x->{value});
2375 # return as octal string, with prefixed 0
2376 my $x = shift; $x = $class->new($x) if !ref($x);
2378 return $x->bstr() if $x->{sign} !~ /^[+-]$/; # inf, nan etc
2380 my $s = ''; $s = $x->{sign} if $x->{sign} eq '-';
2381 return $s . $CALC->_as_oct($x->{value});
2384 ##############################################################################
2385 # private stuff (internal use only)
2389 # check for strings, if yes, return objects instead
2391 # the first argument is number of args objectify() should look at it will
2392 # return $count+1 elements, the first will be a classname. This is because
2393 # overloaded '""' calls bstr($object,undef,undef) and this would result in
2394 # useless objects being created and thrown away. So we cannot simple loop
2395 # over @_. If the given count is 0, all arguments will be used.
2397 # If the second arg is a ref, use it as class.
2398 # If not, try to use it as classname, unless undef, then use $class
2399 # (aka Math::BigInt). The latter shouldn't happen,though.
2402 # $x->badd(1); => ref x, scalar y
2403 # Class->badd(1,2); => classname x (scalar), scalar x, scalar y
2404 # Class->badd( Class->(1),2); => classname x (scalar), ref x, scalar y
2405 # Math::BigInt::badd(1,2); => scalar x, scalar y
2406 # In the last case we check number of arguments to turn it silently into
2407 # $class,1,2. (We can not take '1' as class ;o)
2408 # badd($class,1) is not supported (it should, eventually, try to add undef)
2409 # currently it tries 'Math::BigInt' + 1, which will not work.
2411 # some shortcut for the common cases
2413 return (ref($_[1]),$_[1]) if (@_ == 2) && ($_[0]||0 == 1) && ref($_[1]);
2415 my $count = abs(shift || 0);
2417 my (@a,$k,$d); # resulting array, temp, and downgrade
2420 # okay, got object as first
2425 # nope, got 1,2 (Class->xxx(1) => Class,1 and not supported)
2427 $a[0] = shift if $_[0] =~ /^[A-Z].*::/; # classname as first?
2431 # disable downgrading, because Math::BigFLoat->foo('1.0','2.0') needs floats
2432 if (defined ${"$a[0]::downgrade"})
2434 $d = ${"$a[0]::downgrade"};
2435 ${"$a[0]::downgrade"} = undef;
2438 my $up = ${"$a[0]::upgrade"};
2439 # print STDERR "# Now in objectify, my class is today $a[0], count = $count\n";
2447 $k = $a[0]->new($k);
2449 elsif (!defined $up && ref($k) ne $a[0])
2451 # foreign object, try to convert to integer
2452 $k->can('as_number') ? $k = $k->as_number() : $k = $a[0]->new($k);
2465 $k = $a[0]->new($k);
2467 elsif (!defined $up && ref($k) ne $a[0])
2469 # foreign object, try to convert to integer
2470 $k->can('as_number') ? $k = $k->as_number() : $k = $a[0]->new($k);
2474 push @a,@_; # return other params, too
2478 require Carp; Carp::croak ("$class objectify needs list context");
2480 ${"$a[0]::downgrade"} = $d;
2484 sub _register_callback
2486 my ($class,$callback) = @_;
2488 if (ref($callback) ne 'CODE')
2491 Carp::croak ("$callback is not a coderef");
2493 $CALLBACKS{$class} = $callback;
2500 $IMPORT++; # remember we did import()
2501 my @a; my $l = scalar @_;
2502 my $warn_or_die = 0; # 0 - no warn, 1 - warn, 2 - die
2503 for ( my $i = 0; $i < $l ; $i++ )
2505 if ($_[$i] eq ':constant')
2507 # this causes overlord er load to step in
2509 integer => sub { $self->new(shift) },
2510 binary => sub { $self->new(shift) };
2512 elsif ($_[$i] eq 'upgrade')
2514 # this causes upgrading
2515 $upgrade = $_[$i+1]; # or undef to disable
2518 elsif ($_[$i] =~ /^(lib|try|only)\z/)
2520 # this causes a different low lib to take care...
2521 $CALC = $_[$i+1] || '';
2522 # lib => 1 (warn on fallback), try => 0 (no warn), only => 2 (die on fallback)
2523 $warn_or_die = 1 if $_[$i] eq 'lib';
2524 $warn_or_die = 2 if $_[$i] eq 'only';
2532 # any non :constant stuff is handled by our parent, Exporter
2537 $self->SUPER::import(@a); # need it for subclasses
2538 $self->export_to_level(1,$self,@a); # need it for MBF
2541 # try to load core math lib
2542 my @c = split /\s*,\s*/,$CALC;
2545 $_ =~ tr/a-zA-Z0-9://cd; # limit to sane characters
2547 push @c, \'FastCalc', \'Calc' # if all fail, try these
2548 if $warn_or_die < 2; # but not for "only"
2549 $CALC = ''; # signal error
2552 # fallback libraries are "marked" as \'string', extract string if nec.
2553 my $lib = $l; $lib = $$l if ref($l);
2555 next if ($lib || '') eq '';
2556 $lib = 'Math::BigInt::'.$lib if $lib !~ /^Math::BigInt/i;
2560 # Perl < 5.6.0 dies with "out of memory!" when eval("") and ':constant' is
2561 # used in the same script, or eval("") inside import().
2562 my @parts = split /::/, $lib; # Math::BigInt => Math BigInt
2563 my $file = pop @parts; $file .= '.pm'; # BigInt => BigInt.pm
2565 $file = File::Spec->catfile (@parts, $file);
2566 eval { require "$file"; $lib->import( @c ); }
2570 eval "use $lib qw/@c/;";
2575 # loaded it ok, see if the api_version() is high enough
2576 if ($lib->can('api_version') && $lib->api_version() >= 1.0)
2579 # api_version matches, check if it really provides anything we need
2583 add mul div sub dec inc
2584 acmp len digit is_one is_zero is_even is_odd
2586 zeros new copy check
2587 from_hex from_oct from_bin as_hex as_bin as_oct
2588 rsft lsft xor and or
2589 mod sqrt root fac pow modinv modpow log_int gcd
2592 if (!$lib->can("_$method"))
2594 if (($WARN{$lib}||0) < 2)
2597 Carp::carp ("$lib is missing method '_$method'");
2598 $WARN{$lib} = 1; # still warn about the lib
2607 if ($warn_or_die > 0 && ref($l))
2610 my $msg = "Math::BigInt: couldn't load specified math lib(s), fallback to $lib";
2611 Carp::carp ($msg) if $warn_or_die == 1;
2612 Carp::croak ($msg) if $warn_or_die == 2;
2614 last; # found a usable one, break
2618 if (($WARN{$lib}||0) < 2)
2620 my $ver = eval "\$$lib\::VERSION" || 'unknown';
2622 Carp::carp ("Cannot load outdated $lib v$ver, please upgrade");
2623 $WARN{$lib} = 2; # never warn again
2631 if ($warn_or_die == 2)
2633 Carp::croak ("Couldn't load specified math lib(s) and fallback disallowed");
2637 Carp::croak ("Couldn't load any math lib(s), not even fallback to Calc.pm");
2642 foreach my $class (keys %CALLBACKS)
2644 &{$CALLBACKS{$class}}($CALC);
2647 # Fill $CAN with the results of $CALC->can(...) for emulating lower math lib
2651 for my $method (qw/ signed_and signed_or signed_xor /)
2653 $CAN{$method} = $CALC->can("_$method") ? 1 : 0;
2661 # create a bigint from a hexadecimal string
2662 my ($self, $hs) = @_;
2664 my $rc = $self->__from_hex($hs);
2666 return $self->bnan() unless defined $rc;
2673 # create a bigint from a hexadecimal string
2674 my ($self, $bs) = @_;
2676 my $rc = $self->__from_bin($bs);
2678 return $self->bnan() unless defined $rc;
2685 # create a bigint from a hexadecimal string
2686 my ($self, $os) = @_;
2688 my $x = $self->bzero();
2691 $os =~ s/([0-9a-fA-F])_([0-9a-fA-F])/$1$2/g;
2692 $os =~ s/([0-9a-fA-F])_([0-9a-fA-F])/$1$2/g;
2694 return $x->bnan() if $os !~ /^[\-\+]?0[0-9]+$/;
2696 my $sign = '+'; $sign = '-' if $os =~ /^-/;
2698 $os =~ s/^[+-]//; # strip sign
2699 $x->{value} = $CALC->_from_oct($os);
2700 $x->{sign} = $sign unless $CALC->_is_zero($x->{value}); # no '-0'
2707 # convert a (ref to) big hex string to BigInt, return undef for error
2710 my $x = Math::BigInt->bzero();
2713 $hs =~ s/([0-9a-fA-F])_([0-9a-fA-F])/$1$2/g;
2714 $hs =~ s/([0-9a-fA-F])_([0-9a-fA-F])/$1$2/g;
2716 return $x->bnan() if $hs !~ /^[\-\+]?0x[0-9A-Fa-f]+$/;
2718 my $sign = '+'; $sign = '-' if $hs =~ /^-/;
2720 $hs =~ s/^[+-]//; # strip sign
2721 $x->{value} = $CALC->_from_hex($hs);
2722 $x->{sign} = $sign unless $CALC->_is_zero($x->{value}); # no '-0'
2729 # convert a (ref to) big binary string to BigInt, return undef for error
2732 my $x = Math::BigInt->bzero();
2735 $bs =~ s/([01])_([01])/$1$2/g;
2736 $bs =~ s/([01])_([01])/$1$2/g;
2737 return $x->bnan() if $bs !~ /^[+-]?0b[01]+$/;
2739 my $sign = '+'; $sign = '-' if $bs =~ /^\-/;
2740 $bs =~ s/^[+-]//; # strip sign
2742 $x->{value} = $CALC->_from_bin($bs);
2743 $x->{sign} = $sign unless $CALC->_is_zero($x->{value}); # no '-0'
2749 # input: num_str; output: undef for invalid or
2750 # (\$mantissa_sign,\$mantissa_value,\$mantissa_fraction,\$exp_sign,\$exp_value)
2751 # Internal, take apart a string and return the pieces.
2752 # Strip leading/trailing whitespace, leading zeros, underscore and reject
2756 # strip white space at front, also extranous leading zeros
2757 $x =~ s/^\s*([-]?)0*([0-9])/$1$2/g; # will not strip ' .2'
2758 $x =~ s/^\s+//; # but this will
2759 $x =~ s/\s+$//g; # strip white space at end
2761 # shortcut, if nothing to split, return early
2762 if ($x =~ /^[+-]?[0-9]+\z/)
2764 $x =~ s/^([+-])0*([0-9])/$2/; my $sign = $1 || '+';
2765 return (\$sign, \$x, \'', \'', \0);
2768 # invalid starting char?
2769 return if $x !~ /^[+-]?(\.?[0-9]|0b[0-1]|0x[0-9a-fA-F])/;
2771 return __from_hex($x) if $x =~ /^[\-\+]?0x/; # hex string
2772 return __from_bin($x) if $x =~ /^[\-\+]?0b/; # binary string
2774 # strip underscores between digits
2775 $x =~ s/([0-9])_([0-9])/$1$2/g;
2776 $x =~ s/([0-9])_([0-9])/$1$2/g; # do twice for 1_2_3
2778 # some possible inputs:
2779 # 2.1234 # 0.12 # 1 # 1E1 # 2.134E1 # 434E-10 # 1.02009E-2
2780 # .2 # 1_2_3.4_5_6 # 1.4E1_2_3 # 1e3 # +.2 # 0e999
2782 my ($m,$e,$last) = split /[Ee]/,$x;
2783 return if defined $last; # last defined => 1e2E3 or others
2784 $e = '0' if !defined $e || $e eq "";
2786 # sign,value for exponent,mantint,mantfrac
2787 my ($es,$ev,$mis,$miv,$mfv);
2789 if ($e =~ /^([+-]?)0*([0-9]+)$/) # strip leading zeros
2793 return if $m eq '.' || $m eq '';
2794 my ($mi,$mf,$lastf) = split /\./,$m;
2795 return if defined $lastf; # lastf defined => 1.2.3 or others
2796 $mi = '0' if !defined $mi;
2797 $mi .= '0' if $mi =~ /^[\-\+]?$/;
2798 $mf = '0' if !defined $mf || $mf eq '';
2799 if ($mi =~ /^([+-]?)0*([0-9]+)$/) # strip leading zeros
2801 $mis = $1||'+'; $miv = $2;
2802 return unless ($mf =~ /^([0-9]*?)0*$/); # strip trailing zeros
2804 # handle the 0e999 case here
2805 $ev = 0 if $miv eq '0' && $mfv eq '';
2806 return (\$mis,\$miv,\$mfv,\$es,\$ev);
2809 return; # NaN, not a number
2812 ##############################################################################
2813 # internal calculation routines (others are in Math::BigInt::Calc etc)
2817 # (BINT or num_str, BINT or num_str) return BINT
2818 # does modify first argument
2822 return $x->bnan() if ($x->{sign} eq $nan) || ($ty->{sign} eq $nan);
2823 my $method = ref($x) . '::bgcd';
2825 $x * $ty / &$method($x,$ty);
2828 ###############################################################################
2829 # this method returns 0 if the object can be modified, or 1 if not.
2830 # We use a fast constant sub() here, to avoid costly calls. Subclasses
2831 # may override it with special code (f.i. Math::BigInt::Constant does so)
2833 sub modify () { 0; }
2842 Math::BigInt - Arbitrary size integer/float math package
2848 # or make it faster: install (optional) Math::BigInt::GMP
2849 # and always use (it will fall back to pure Perl if the
2850 # GMP library is not installed):
2852 # will warn if Math::BigInt::GMP cannot be found
2853 use Math::BigInt lib => 'GMP';
2855 # to supress the warning use this:
2856 # use Math::BigInt try => 'GMP';
2858 my $str = '1234567890';
2859 my @values = (64,74,18);
2860 my $n = 1; my $sign = '-';
2863 $x = Math::BigInt->new($str); # defaults to 0
2864 $y = $x->copy(); # make a true copy
2865 $nan = Math::BigInt->bnan(); # create a NotANumber
2866 $zero = Math::BigInt->bzero(); # create a +0
2867 $inf = Math::BigInt->binf(); # create a +inf
2868 $inf = Math::BigInt->binf('-'); # create a -inf
2869 $one = Math::BigInt->bone(); # create a +1
2870 $one = Math::BigInt->bone('-'); # create a -1
2872 $h = Math::BigInt->new('0x123'); # from hexadecimal
2873 $b = Math::BigInt->new('0b101'); # from binary
2874 $o = Math::BigInt->from_oct('0101'); # from octal
2876 # Testing (don't modify their arguments)
2877 # (return true if the condition is met, otherwise false)
2879 $x->is_zero(); # if $x is +0
2880 $x->is_nan(); # if $x is NaN
2881 $x->is_one(); # if $x is +1
2882 $x->is_one('-'); # if $x is -1
2883 $x->is_odd(); # if $x is odd
2884 $x->is_even(); # if $x is even
2885 $x->is_pos(); # if $x >= 0
2886 $x->is_neg(); # if $x < 0
2887 $x->is_inf($sign); # if $x is +inf, or -inf (sign is default '+')
2888 $x->is_int(); # if $x is an integer (not a float)
2890 # comparing and digit/sign extraction
2891 $x->bcmp($y); # compare numbers (undef,<0,=0,>0)
2892 $x->bacmp($y); # compare absolutely (undef,<0,=0,>0)
2893 $x->sign(); # return the sign, either +,- or NaN
2894 $x->digit($n); # return the nth digit, counting from right
2895 $x->digit(-$n); # return the nth digit, counting from left
2897 # The following all modify their first argument. If you want to preserve
2898 # $x, use $z = $x->copy()->bXXX($y); See under L<CAVEATS> for why this is
2899 # necessary when mixing $a = $b assignments with non-overloaded math.
2901 $x->bzero(); # set $x to 0
2902 $x->bnan(); # set $x to NaN
2903 $x->bone(); # set $x to +1
2904 $x->bone('-'); # set $x to -1
2905 $x->binf(); # set $x to inf
2906 $x->binf('-'); # set $x to -inf
2908 $x->bneg(); # negation
2909 $x->babs(); # absolute value
2910 $x->bnorm(); # normalize (no-op in BigInt)
2911 $x->bnot(); # two's complement (bit wise not)
2912 $x->binc(); # increment $x by 1
2913 $x->bdec(); # decrement $x by 1
2915 $x->badd($y); # addition (add $y to $x)
2916 $x->bsub($y); # subtraction (subtract $y from $x)
2917 $x->bmul($y); # multiplication (multiply $x by $y)
2918 $x->bdiv($y); # divide, set $x to quotient
2919 # return (quo,rem) or quo if scalar
2921 $x->bmod($y); # modulus (x % y)
2922 $x->bmodpow($exp,$mod); # modular exponentation (($num**$exp) % $mod))
2923 $x->bmodinv($mod); # the inverse of $x in the given modulus $mod
2925 $x->bpow($y); # power of arguments (x ** y)
2926 $x->blsft($y); # left shift in base 2
2927 $x->brsft($y); # right shift in base 2
2928 # returns (quo,rem) or quo if in scalar context
2929 $x->blsft($y,$n); # left shift by $y places in base $n
2930 $x->brsft($y,$n); # right shift by $y places in base $n
2931 # returns (quo,rem) or quo if in scalar context
2933 $x->band($y); # bitwise and
2934 $x->bior($y); # bitwise inclusive or
2935 $x->bxor($y); # bitwise exclusive or
2936 $x->bnot(); # bitwise not (two's complement)
2938 $x->bsqrt(); # calculate square-root
2939 $x->broot($y); # $y'th root of $x (e.g. $y == 3 => cubic root)
2940 $x->bfac(); # factorial of $x (1*2*3*4*..$x)
2942 $x->bnok($y); # x over y (binomial coefficient n over k)
2944 $x->blog(); # logarithm of $x to base e (Euler's number)
2945 $x->blog($base); # logarithm of $x to base $base (f.i. 2)
2946 $x->bexp(); # calculate e ** $x where e is Euler's number
2948 $x->round($A,$P,$mode); # round to accuracy or precision using mode $mode
2949 $x->bround($n); # accuracy: preserve $n digits
2950 $x->bfround($n); # round to $nth digit, no-op for BigInts
2952 # The following do not modify their arguments in BigInt (are no-ops),
2953 # but do so in BigFloat:
2955 $x->bfloor(); # return integer less or equal than $x
2956 $x->bceil(); # return integer greater or equal than $x
2958 # The following do not modify their arguments:
2960 # greatest common divisor (no OO style)
2961 my $gcd = Math::BigInt::bgcd(@values);
2962 # lowest common multiplicator (no OO style)
2963 my $lcm = Math::BigInt::blcm(@values);
2965 $x->length(); # return number of digits in number
2966 ($xl,$f) = $x->length(); # length of number and length of fraction part,
2967 # latter is always 0 digits long for BigInts
2969 $x->exponent(); # return exponent as BigInt
2970 $x->mantissa(); # return (signed) mantissa as BigInt
2971 $x->parts(); # return (mantissa,exponent) as BigInt
2972 $x->copy(); # make a true copy of $x (unlike $y = $x;)
2973 $x->as_int(); # return as BigInt (in BigInt: same as copy())
2974 $x->numify(); # return as scalar (might overflow!)
2976 # conversation to string (do not modify their argument)
2977 $x->bstr(); # normalized string (e.g. '3')
2978 $x->bsstr(); # norm. string in scientific notation (e.g. '3E0')
2979 $x->as_hex(); # as signed hexadecimal string with prefixed 0x
2980 $x->as_bin(); # as signed binary string with prefixed 0b
2981 $x->as_oct(); # as signed octal string with prefixed 0
2984 # precision and accuracy (see section about rounding for more)
2985 $x->precision(); # return P of $x (or global, if P of $x undef)
2986 $x->precision($n); # set P of $x to $n
2987 $x->accuracy(); # return A of $x (or global, if A of $x undef)
2988 $x->accuracy($n); # set A $x to $n
2991 Math::BigInt->precision(); # get/set global P for all BigInt objects
2992 Math::BigInt->accuracy(); # get/set global A for all BigInt objects
2993 Math::BigInt->round_mode(); # get/set global round mode, one of
2994 # 'even', 'odd', '+inf', '-inf', 'zero', 'trunc' or 'common'
2995 Math::BigInt->config(); # return hash containing configuration
2999 All operators (including basic math operations) are overloaded if you
3000 declare your big integers as
3002 $i = new Math::BigInt '123_456_789_123_456_789';
3004 Operations with overloaded operators preserve the arguments which is
3005 exactly what you expect.
3011 Input values to these routines may be any string, that looks like a number
3012 and results in an integer, including hexadecimal and binary numbers.
3014 Scalars holding numbers may also be passed, but note that non-integer numbers
3015 may already have lost precision due to the conversation to float. Quote
3016 your input if you want BigInt to see all the digits:
3018 $x = Math::BigInt->new(12345678890123456789); # bad
3019 $x = Math::BigInt->new('12345678901234567890'); # good
3021 You can include one underscore between any two digits.
3023 This means integer values like 1.01E2 or even 1000E-2 are also accepted.
3024 Non-integer values result in NaN.
3026 Hexadecimal (prefixed with "0x") and binary numbers (prefixed with "0b")
3027 are accepted, too. Please note that octal numbers are not recognized
3028 by new(), so the following will print "123":
3030 perl -MMath::BigInt -le 'print Math::BigInt->new("0123")'
3032 To convert an octal number, use from_oct();
3034 perl -MMath::BigInt -le 'print Math::BigInt->from_oct("0123")'
3036 Currently, Math::BigInt::new() defaults to 0, while Math::BigInt::new('')
3037 results in 'NaN'. This might change in the future, so use always the following
3038 explicit forms to get a zero or NaN:
3040 $zero = Math::BigInt->bzero();
3041 $nan = Math::BigInt->bnan();
3043 C<bnorm()> on a BigInt object is now effectively a no-op, since the numbers
3044 are always stored in normalized form. If passed a string, creates a BigInt
3045 object from the input.
3049 Output values are BigInt objects (normalized), except for the methods which
3050 return a string (see L<SYNOPSIS>).
3052 Some routines (C<is_odd()>, C<is_even()>, C<is_zero()>, C<is_one()>,
3053 C<is_nan()>, etc.) return true or false, while others (C<bcmp()>, C<bacmp()>)
3054 return either undef (if NaN is involved), <0, 0 or >0 and are suited for sort.
3060 Each of the methods below (except config(), accuracy() and precision())
3061 accepts three additional parameters. These arguments C<$A>, C<$P> and C<$R>
3062 are C<accuracy>, C<precision> and C<round_mode>. Please see the section about
3063 L<ACCURACY and PRECISION> for more information.
3069 print Dumper ( Math::BigInt->config() );
3070 print Math::BigInt->config()->{lib},"\n";
3072 Returns a hash containing the configuration, e.g. the version number, lib
3073 loaded etc. The following hash keys are currently filled in with the
3074 appropriate information.
3078 ============================================================
3079 lib Name of the low-level math library
3081 lib_version Version of low-level math library (see 'lib')
3083 class The class name of config() you just called
3085 upgrade To which class math operations might be upgraded
3087 downgrade To which class math operations might be downgraded
3089 precision Global precision
3091 accuracy Global accuracy
3093 round_mode Global round mode
3095 version version number of the class you used
3097 div_scale Fallback accuracy for div
3099 trap_nan If true, traps creation of NaN via croak()
3101 trap_inf If true, traps creation of +inf/-inf via croak()
3104 The following values can be set by passing C<config()> a reference to a hash:
3107 upgrade downgrade precision accuracy round_mode div_scale
3111 $new_cfg = Math::BigInt->config( { trap_inf => 1, precision => 5 } );
3115 $x->accuracy(5); # local for $x
3116 CLASS->accuracy(5); # global for all members of CLASS
3117 # Note: This also applies to new()!
3119 $A = $x->accuracy(); # read out accuracy that affects $x
3120 $A = CLASS->accuracy(); # read out global accuracy
3122 Set or get the global or local accuracy, aka how many significant digits the
3123 results have. If you set a global accuracy, then this also applies to new()!
3125 Warning! The accuracy I<sticks>, e.g. once you created a number under the
3126 influence of C<< CLASS->accuracy($A) >>, all results from math operations with
3127 that number will also be rounded.
3129 In most cases, you should probably round the results explicitly using one of
3130 L<round()>, L<bround()> or L<bfround()> or by passing the desired accuracy
3131 to the math operation as additional parameter:
3133 my $x = Math::BigInt->new(30000);
3134 my $y = Math::BigInt->new(7);
3135 print scalar $x->copy()->bdiv($y, 2); # print 4300
3136 print scalar $x->copy()->bdiv($y)->bround(2); # print 4300
3138 Please see the section about L<ACCURACY AND PRECISION> for further details.
3140 Value must be greater than zero. Pass an undef value to disable it:
3142 $x->accuracy(undef);
3143 Math::BigInt->accuracy(undef);
3145 Returns the current accuracy. For C<$x->accuracy()> it will return either the
3146 local accuracy, or if not defined, the global. This means the return value
3147 represents the accuracy that will be in effect for $x:
3149 $y = Math::BigInt->new(1234567); # unrounded
3150 print Math::BigInt->accuracy(4),"\n"; # set 4, print 4
3151 $x = Math::BigInt->new(123456); # $x will be automatically rounded!
3152 print "$x $y\n"; # '123500 1234567'
3153 print $x->accuracy(),"\n"; # will be 4
3154 print $y->accuracy(),"\n"; # also 4, since global is 4
3155 print Math::BigInt->accuracy(5),"\n"; # set to 5, print 5
3156 print $x->accuracy(),"\n"; # still 4
3157 print $y->accuracy(),"\n"; # 5, since global is 5
3159 Note: Works also for subclasses like Math::BigFloat. Each class has it's own
3160 globals separated from Math::BigInt, but it is possible to subclass
3161 Math::BigInt and make the globals of the subclass aliases to the ones from
3166 $x->precision(-2); # local for $x, round at the second digit right of the dot
3167 $x->precision(2); # ditto, round at the second digit left of the dot
3169 CLASS->precision(5); # Global for all members of CLASS
3170 # This also applies to new()!
3171 CLASS->precision(-5); # ditto
3173 $P = CLASS->precision(); # read out global precision
3174 $P = $x->precision(); # read out precision that affects $x
3176 Note: You probably want to use L<accuracy()> instead. With L<accuracy> you
3177 set the number of digits each result should have, with L<precision> you
3178 set the place where to round!
3180 C<precision()> sets or gets the global or local precision, aka at which digit
3181 before or after the dot to round all results. A set global precision also
3182 applies to all newly created numbers!
3184 In Math::BigInt, passing a negative number precision has no effect since no
3185 numbers have digits after the dot. In L<Math::BigFloat>, it will round all
3186 results to P digits after the dot.
3188 Please see the section about L<ACCURACY AND PRECISION> for further details.
3190 Pass an undef value to disable it:
3192 $x->precision(undef);
3193 Math::BigInt->precision(undef);
3195 Returns the current precision. For C<$x->precision()> it will return either the
3196 local precision of $x, or if not defined, the global. This means the return
3197 value represents the prevision that will be in effect for $x:
3199 $y = Math::BigInt->new(1234567); # unrounded
3200 print Math::BigInt->precision(4),"\n"; # set 4, print 4
3201 $x = Math::BigInt->new(123456); # will be automatically rounded
3202 print $x; # print "120000"!
3204 Note: Works also for subclasses like L<Math::BigFloat>. Each class has its
3205 own globals separated from Math::BigInt, but it is possible to subclass
3206 Math::BigInt and make the globals of the subclass aliases to the ones from
3213 Shifts $x right by $y in base $n. Default is base 2, used are usually 10 and
3214 2, but others work, too.
3216 Right shifting usually amounts to dividing $x by $n ** $y and truncating the
3220 $x = Math::BigInt->new(10);
3221 $x->brsft(1); # same as $x >> 1: 5
3222 $x = Math::BigInt->new(1234);
3223 $x->brsft(2,10); # result 12
3225 There is one exception, and that is base 2 with negative $x:
3228 $x = Math::BigInt->new(-5);
3231 This will print -3, not -2 (as it would if you divide -5 by 2 and truncate the
3236 $x = Math::BigInt->new($str,$A,$P,$R);
3238 Creates a new BigInt object from a scalar or another BigInt object. The
3239 input is accepted as decimal, hex (with leading '0x') or binary (with leading
3242 See L<Input> for more info on accepted input formats.
3246 $x = Math::BigIn->from_oct("0775"); # input is octal
3250 $x = Math::BigIn->from_hex("0xcafe"); # input is hexadecimal
3254 $x = Math::BigIn->from_oct("0x10011"); # input is binary
3258 $x = Math::BigInt->bnan();
3260 Creates a new BigInt object representing NaN (Not A Number).
3261 If used on an object, it will set it to NaN:
3267 $x = Math::BigInt->bzero();
3269 Creates a new BigInt object representing zero.
3270 If used on an object, it will set it to zero:
3276 $x = Math::BigInt->binf($sign);
3278 Creates a new BigInt object representing infinity. The optional argument is
3279 either '-' or '+', indicating whether you want infinity or minus infinity.
3280 If used on an object, it will set it to infinity:
3287 $x = Math::BigInt->binf($sign);
3289 Creates a new BigInt object representing one. The optional argument is
3290 either '-' or '+', indicating whether you want one or minus one.
3291 If used on an object, it will set it to one:
3296 =head2 is_one()/is_zero()/is_nan()/is_inf()
3299 $x->is_zero(); # true if arg is +0
3300 $x->is_nan(); # true if arg is NaN
3301 $x->is_one(); # true if arg is +1
3302 $x->is_one('-'); # true if arg is -1
3303 $x->is_inf(); # true if +inf
3304 $x->is_inf('-'); # true if -inf (sign is default '+')
3306 These methods all test the BigInt for being one specific value and return
3307 true or false depending on the input. These are faster than doing something
3312 =head2 is_pos()/is_neg()/is_positive()/is_negative()
3314 $x->is_pos(); # true if > 0
3315 $x->is_neg(); # true if < 0
3317 The methods return true if the argument is positive or negative, respectively.
3318 C<NaN> is neither positive nor negative, while C<+inf> counts as positive, and
3319 C<-inf> is negative. A C<zero> is neither positive nor negative.
3321 These methods are only testing the sign, and not the value.
3323 C<is_positive()> and C<is_negative()> are aliases to C<is_pos()> and
3324 C<is_neg()>, respectively. C<is_positive()> and C<is_negative()> were
3325 introduced in v1.36, while C<is_pos()> and C<is_neg()> were only introduced
3328 =head2 is_odd()/is_even()/is_int()
3330 $x->is_odd(); # true if odd, false for even
3331 $x->is_even(); # true if even, false for odd
3332 $x->is_int(); # true if $x is an integer
3334 The return true when the argument satisfies the condition. C<NaN>, C<+inf>,
3335 C<-inf> are not integers and are neither odd nor even.
3337 In BigInt, all numbers except C<NaN>, C<+inf> and C<-inf> are integers.
3343 Compares $x with $y and takes the sign into account.
3344 Returns -1, 0, 1 or undef.
3350 Compares $x with $y while ignoring their. Returns -1, 0, 1 or undef.
3356 Return the sign, of $x, meaning either C<+>, C<->, C<-inf>, C<+inf> or NaN.
3358 If you want $x to have a certain sign, use one of the following methods:
3361 $x->babs()->bneg(); # '-'
3363 $x->binf(); # '+inf'
3364 $x->binf('-'); # '-inf'
3368 $x->digit($n); # return the nth digit, counting from right
3370 If C<$n> is negative, returns the digit counting from left.
3376 Negate the number, e.g. change the sign between '+' and '-', or between '+inf'
3377 and '-inf', respectively. Does nothing for NaN or zero.
3383 Set the number to it's absolute value, e.g. change the sign from '-' to '+'
3384 and from '-inf' to '+inf', respectively. Does nothing for NaN or positive
3389 $x->bnorm(); # normalize (no-op)
3395 Two's complement (bit wise not). This is equivalent to
3403 $x->binc(); # increment x by 1
3407 $x->bdec(); # decrement x by 1
3411 $x->badd($y); # addition (add $y to $x)
3415 $x->bsub($y); # subtraction (subtract $y from $x)
3419 $x->bmul($y); # multiplication (multiply $x by $y)
3423 $x->bdiv($y); # divide, set $x to quotient
3424 # return (quo,rem) or quo if scalar
3428 $x->bmod($y); # modulus (x % y)
3432 num->bmodinv($mod); # modular inverse
3434 Returns the inverse of C<$num> in the given modulus C<$mod>. 'C<NaN>' is
3435 returned unless C<$num> is relatively prime to C<$mod>, i.e. unless
3436 C<bgcd($num, $mod)==1>.
3440 $num->bmodpow($exp,$mod); # modular exponentation
3441 # ($num**$exp % $mod)
3443 Returns the value of C<$num> taken to the power C<$exp> in the modulus
3444 C<$mod> using binary exponentation. C<bmodpow> is far superior to
3449 because it is much faster - it reduces internal variables into
3450 the modulus whenever possible, so it operates on smaller numbers.
3452 C<bmodpow> also supports negative exponents.
3454 bmodpow($num, -1, $mod)
3456 is exactly equivalent to
3462 $x->bpow($y); # power of arguments (x ** y)
3466 $x->blog($base, $accuracy); # logarithm of x to the base $base
3468 If C<$base> is not defined, Euler's number (e) is used:
3470 print $x->blog(undef, 100); # log(x) to 100 digits
3474 $x->bexp($accuracy); # calculate e ** X
3476 Calculates the expression C<e ** $x> where C<e> is Euler's number.
3478 This method was added in v1.82 of Math::BigInt (April 2007).
3484 $x->bnok($y); # x over y (binomial coefficient n over k)
3486 Calculates the binomial coefficient n over k, also called the "choose"
3487 function. The result is equivalent to:
3493 This method was added in v1.84 of Math::BigInt (April 2007).
3497 $x->blsft($y); # left shift in base 2
3498 $x->blsft($y,$n); # left shift, in base $n (like 10)
3502 $x->brsft($y); # right shift in base 2
3503 $x->brsft($y,$n); # right shift, in base $n (like 10)
3507 $x->band($y); # bitwise and
3511 $x->bior($y); # bitwise inclusive or
3515 $x->bxor($y); # bitwise exclusive or
3519 $x->bnot(); # bitwise not (two's complement)
3523 $x->bsqrt(); # calculate square-root
3527 $x->bfac(); # factorial of $x (1*2*3*4*..$x)
3531 $x->round($A,$P,$round_mode);
3533 Round $x to accuracy C<$A> or precision C<$P> using the round mode
3538 $x->bround($N); # accuracy: preserve $N digits
3542 $x->bfround($N); # round to $Nth digit, no-op for BigInts
3548 Set $x to the integer less or equal than $x. This is a no-op in BigInt, but
3549 does change $x in BigFloat.
3555 Set $x to the integer greater or equal than $x. This is a no-op in BigInt, but
3556 does change $x in BigFloat.
3560 bgcd(@values); # greatest common divisor (no OO style)
3564 blcm(@values); # lowest common multiplicator (no OO style)
3569 ($xl,$fl) = $x->length();
3571 Returns the number of digits in the decimal representation of the number.
3572 In list context, returns the length of the integer and fraction part. For
3573 BigInt's, the length of the fraction part will always be 0.
3579 Return the exponent of $x as BigInt.
3585 Return the signed mantissa of $x as BigInt.
3589 $x->parts(); # return (mantissa,exponent) as BigInt
3593 $x->copy(); # make a true copy of $x (unlike $y = $x;)
3595 =head2 as_int()/as_number()
3599 Returns $x as a BigInt (truncated towards zero). In BigInt this is the same as
3602 C<as_number()> is an alias to this method. C<as_number> was introduced in
3603 v1.22, while C<as_int()> was only introduced in v1.68.
3609 Returns a normalized string representation of C<$x>.
3613 $x->bsstr(); # normalized string in scientific notation
3617 $x->as_hex(); # as signed hexadecimal string with prefixed 0x
3621 $x->as_bin(); # as signed binary string with prefixed 0b
3625 $x->as_oct(); # as signed octal string with prefixed 0
3631 This returns a normal Perl scalar from $x. It is used automatically
3632 whenever a scalar is needed, for instance in array index operations.
3634 This loses precision, to avoid this use L<as_int()> instead.
3638 $x->modify('bpowd');
3640 This method returns 0 if the object can be modified with the given
3641 peration, or 1 if not.
3643 This is used for instance by L<Math::BigInt::Constant>.
3645 =head2 upgrade()/downgrade()
3647 Set/get the class for downgrade/upgrade operations. Thuis is used
3648 for instance by L<bignum>. The defaults are '', thus the following
3649 operation will create a BigInt, not a BigFloat:
3651 my $i = Math::BigInt->new(123);
3652 my $f = Math::BigFloat->new('123.1');
3654 print $i + $f,"\n"; # print 246
3658 Set/get the number of digits for the default precision in divide
3663 Set/get the current round mode.
3665 =head1 ACCURACY and PRECISION
3667 Since version v1.33, Math::BigInt and Math::BigFloat have full support for
3668 accuracy and precision based rounding, both automatically after every
3669 operation, as well as manually.
3671 This section describes the accuracy/precision handling in Math::Big* as it
3672 used to be and as it is now, complete with an explanation of all terms and
3675 Not yet implemented things (but with correct description) are marked with '!',
3676 things that need to be answered are marked with '?'.
3678 In the next paragraph follows a short description of terms used here (because
3679 these may differ from terms used by others people or documentation).
3681 During the rest of this document, the shortcuts A (for accuracy), P (for
3682 precision), F (fallback) and R (rounding mode) will be used.
3686 A fixed number of digits before (positive) or after (negative)
3687 the decimal point. For example, 123.45 has a precision of -2. 0 means an
3688 integer like 123 (or 120). A precision of 2 means two digits to the left
3689 of the decimal point are zero, so 123 with P = 1 becomes 120. Note that
3690 numbers with zeros before the decimal point may have different precisions,
3691 because 1200 can have p = 0, 1 or 2 (depending on what the inital value
3692 was). It could also have p < 0, when the digits after the decimal point
3695 The string output (of floating point numbers) will be padded with zeros:
3697 Initial value P A Result String
3698 ------------------------------------------------------------
3699 1234.01 -3 1000 1000
3702 1234.001 1 1234 1234.0
3704 1234.01 2 1234.01 1234.01
3705 1234.01 5 1234.01 1234.01000
3707 For BigInts, no padding occurs.
3711 Number of significant digits. Leading zeros are not counted. A
3712 number may have an accuracy greater than the non-zero digits
3713 when there are zeros in it or trailing zeros. For example, 123.456 has
3714 A of 6, 10203 has 5, 123.0506 has 7, 123.450000 has 8 and 0.000123 has 3.
3716 The string output (of floating point numbers) will be padded with zeros:
3718 Initial value P A Result String
3719 ------------------------------------------------------------
3721 1234.01 6 1234.01 1234.01
3722 1234.1 8 1234.1 1234.1000
3724 For BigInts, no padding occurs.
3728 When both A and P are undefined, this is used as a fallback accuracy when
3731 =head2 Rounding mode R
3733 When rounding a number, different 'styles' or 'kinds'
3734 of rounding are possible. (Note that random rounding, as in
3735 Math::Round, is not implemented.)
3741 truncation invariably removes all digits following the
3742 rounding place, replacing them with zeros. Thus, 987.65 rounded
3743 to tens (P=1) becomes 980, and rounded to the fourth sigdig
3744 becomes 987.6 (A=4). 123.456 rounded to the second place after the
3745 decimal point (P=-2) becomes 123.46.
3747 All other implemented styles of rounding attempt to round to the
3748 "nearest digit." If the digit D immediately to the right of the
3749 rounding place (skipping the decimal point) is greater than 5, the
3750 number is incremented at the rounding place (possibly causing a
3751 cascade of incrementation): e.g. when rounding to units, 0.9 rounds
3752 to 1, and -19.9 rounds to -20. If D < 5, the number is similarly
3753 truncated at the rounding place: e.g. when rounding to units, 0.4
3754 rounds to 0, and -19.4 rounds to -19.
3756 However the results of other styles of rounding differ if the
3757 digit immediately to the right of the rounding place (skipping the
3758 decimal point) is 5 and if there are no digits, or no digits other
3759 than 0, after that 5. In such cases:
3763 rounds the digit at the rounding place to 0, 2, 4, 6, or 8
3764 if it is not already. E.g., when rounding to the first sigdig, 0.45
3765 becomes 0.4, -0.55 becomes -0.6, but 0.4501 becomes 0.5.
3769 rounds the digit at the rounding place to 1, 3, 5, 7, or 9 if
3770 it is not already. E.g., when rounding to the first sigdig, 0.45
3771 becomes 0.5, -0.55 becomes -0.5, but 0.5501 becomes 0.6.
3775 round to plus infinity, i.e. always round up. E.g., when
3776 rounding to the first sigdig, 0.45 becomes 0.5, -0.55 becomes -0.5,
3777 and 0.4501 also becomes 0.5.
3781 round to minus infinity, i.e. always round down. E.g., when
3782 rounding to the first sigdig, 0.45 becomes 0.4, -0.55 becomes -0.6,
3783 but 0.4501 becomes 0.5.
3787 round to zero, i.e. positive numbers down, negative ones up.
3788 E.g., when rounding to the first sigdig, 0.45 becomes 0.4, -0.55
3789 becomes -0.5, but 0.4501 becomes 0.5.
3793 round up if the digit immediately to the right of the rounding place
3794 is 5 or greater, otherwise round down. E.g., 0.15 becomes 0.2 and
3799 The handling of A & P in MBI/MBF (the old core code shipped with Perl
3800 versions <= 5.7.2) is like this:
3806 * ffround($p) is able to round to $p number of digits after the decimal
3808 * otherwise P is unused
3810 =item Accuracy (significant digits)
3812 * fround($a) rounds to $a significant digits
3813 * only fdiv() and fsqrt() take A as (optional) paramater
3814 + other operations simply create the same number (fneg etc), or more (fmul)
3816 + rounding/truncating is only done when explicitly calling one of fround
3817 or ffround, and never for BigInt (not implemented)
3818 * fsqrt() simply hands its accuracy argument over to fdiv.
3819 * the documentation and the comment in the code indicate two different ways
3820 on how fdiv() determines the maximum number of digits it should calculate,
3821 and the actual code does yet another thing
3823 max($Math::BigFloat::div_scale,length(dividend)+length(divisor))
3825 result has at most max(scale, length(dividend), length(divisor)) digits
3827 scale = max(scale, length(dividend)-1,length(divisor)-1);
3828 scale += length(divisor) - length(dividend);
3829 So for lx = 3, ly = 9, scale = 10, scale will actually be 16 (10+9-3).
3830 Actually, the 'difference' added to the scale is calculated from the
3831 number of "significant digits" in dividend and divisor, which is derived
3832 by looking at the length of the mantissa. Which is wrong, since it includes
3833 the + sign (oops) and actually gets 2 for '+100' and 4 for '+101'. Oops
3834 again. Thus 124/3 with div_scale=1 will get you '41.3' based on the strange
3835 assumption that 124 has 3 significant digits, while 120/7 will get you
3836 '17', not '17.1' since 120 is thought to have 2 significant digits.
3837 The rounding after the division then uses the remainder and $y to determine
3838 wether it must round up or down.
3839 ? I have no idea which is the right way. That's why I used a slightly more
3840 ? simple scheme and tweaked the few failing testcases to match it.
3844 This is how it works now:
3848 =item Setting/Accessing
3850 * You can set the A global via C<< Math::BigInt->accuracy() >> or
3851 C<< Math::BigFloat->accuracy() >> or whatever class you are using.
3852 * You can also set P globally by using C<< Math::SomeClass->precision() >>
3854 * Globals are classwide, and not inherited by subclasses.
3855 * to undefine A, use C<< Math::SomeCLass->accuracy(undef); >>
3856 * to undefine P, use C<< Math::SomeClass->precision(undef); >>
3857 * Setting C<< Math::SomeClass->accuracy() >> clears automatically
3858 C<< Math::SomeClass->precision() >>, and vice versa.
3859 * To be valid, A must be > 0, P can have any value.
3860 * If P is negative, this means round to the P'th place to the right of the
3861 decimal point; positive values mean to the left of the decimal point.
3862 P of 0 means round to integer.
3863 * to find out the current global A, use C<< Math::SomeClass->accuracy() >>
3864 * to find out the current global P, use C<< Math::SomeClass->precision() >>
3865 * use C<< $x->accuracy() >> respective C<< $x->precision() >> for the local
3866 setting of C<< $x >>.
3867 * Please note that C<< $x->accuracy() >> respective C<< $x->precision() >>
3868 return eventually defined global A or P, when C<< $x >>'s A or P is not
3871 =item Creating numbers
3873 * When you create a number, you can give it's desired A or P via:
3874 $x = Math::BigInt->new($number,$A,$P);
3875 * Only one of A or P can be defined, otherwise the result is NaN
3876 * If no A or P is give ($x = Math::BigInt->new($number) form), then the
3877 globals (if set) will be used. Thus changing the global defaults later on
3878 will not change the A or P of previously created numbers (i.e., A and P of
3879 $x will be what was in effect when $x was created)
3880 * If given undef for A and P, B<no> rounding will occur, and the globals will
3881 B<not> be used. This is used by subclasses to create numbers without
3882 suffering rounding in the parent. Thus a subclass is able to have it's own
3883 globals enforced upon creation of a number by using
3884 C<< $x = Math::BigInt->new($number,undef,undef) >>:
3886 use Math::BigInt::SomeSubclass;
3889 Math::BigInt->accuracy(2);
3890 Math::BigInt::SomeSubClass->accuracy(3);
3891 $x = Math::BigInt::SomeSubClass->new(1234);
3893 $x is now 1230, and not 1200. A subclass might choose to implement
3894 this otherwise, e.g. falling back to the parent's A and P.
3898 * If A or P are enabled/defined, they are used to round the result of each
3899 operation according to the rules below
3900 * Negative P is ignored in Math::BigInt, since BigInts never have digits
3901 after the decimal point
3902 * Math::BigFloat uses Math::BigInt internally, but setting A or P inside
3903 Math::BigInt as globals does not tamper with the parts of a BigFloat.
3904 A flag is used to mark all Math::BigFloat numbers as 'never round'.
3908 * It only makes sense that a number has only one of A or P at a time.
3909 If you set either A or P on one object, or globally, the other one will
3910 be automatically cleared.
3911 * If two objects are involved in an operation, and one of them has A in
3912 effect, and the other P, this results in an error (NaN).
3913 * A takes precedence over P (Hint: A comes before P).
3914 If neither of them is defined, nothing is used, i.e. the result will have
3915 as many digits as it can (with an exception for fdiv/fsqrt) and will not
3917 * There is another setting for fdiv() (and thus for fsqrt()). If neither of
3918 A or P is defined, fdiv() will use a fallback (F) of $div_scale digits.
3919 If either the dividend's or the divisor's mantissa has more digits than
3920 the value of F, the higher value will be used instead of F.
3921 This is to limit the digits (A) of the result (just consider what would
3922 happen with unlimited A and P in the case of 1/3 :-)
3923 * fdiv will calculate (at least) 4 more digits than required (determined by
3924 A, P or F), and, if F is not used, round the result
3925 (this will still fail in the case of a result like 0.12345000000001 with A
3926 or P of 5, but this can not be helped - or can it?)
3927 * Thus you can have the math done by on Math::Big* class in two modi:
3928 + never round (this is the default):
3929 This is done by setting A and P to undef. No math operation
3930 will round the result, with fdiv() and fsqrt() as exceptions to guard
3931 against overflows. You must explicitly call bround(), bfround() or
3932 round() (the latter with parameters).
3933 Note: Once you have rounded a number, the settings will 'stick' on it
3934 and 'infect' all other numbers engaged in math operations with it, since
3935 local settings have the highest precedence. So, to get SaferRound[tm],
3936 use a copy() before rounding like this:
3938 $x = Math::BigFloat->new(12.34);
3939 $y = Math::BigFloat->new(98.76);
3940 $z = $x * $y; # 1218.6984
3941 print $x->copy()->fround(3); # 12.3 (but A is now 3!)
3942 $z = $x * $y; # still 1218.6984, without
3943 # copy would have been 1210!
3945 + round after each op:
3946 After each single operation (except for testing like is_zero()), the
3947 method round() is called and the result is rounded appropriately. By
3948 setting proper values for A and P, you can have all-the-same-A or
3949 all-the-same-P modes. For example, Math::Currency might set A to undef,
3950 and P to -2, globally.
3952 ?Maybe an extra option that forbids local A & P settings would be in order,
3953 ?so that intermediate rounding does not 'poison' further math?
3955 =item Overriding globals
3957 * you will be able to give A, P and R as an argument to all the calculation
3958 routines; the second parameter is A, the third one is P, and the fourth is
3959 R (shift right by one for binary operations like badd). P is used only if
3960 the first parameter (A) is undefined. These three parameters override the
3961 globals in the order detailed as follows, i.e. the first defined value
3963 (local: per object, global: global default, parameter: argument to sub)
3966 + local A (if defined on both of the operands: smaller one is taken)
3967 + local P (if defined on both of the operands: bigger one is taken)
3971 * fsqrt() will hand its arguments to fdiv(), as it used to, only now for two
3972 arguments (A and P) instead of one
3974 =item Local settings
3976 * You can set A or P locally by using C<< $x->accuracy() >> or
3977 C<< $x->precision() >>
3978 and thus force different A and P for different objects/numbers.
3979 * Setting A or P this way immediately rounds $x to the new value.
3980 * C<< $x->accuracy() >> clears C<< $x->precision() >>, and vice versa.
3984 * the rounding routines will use the respective global or local settings.
3985 fround()/bround() is for accuracy rounding, while ffround()/bfround()
3987 * the two rounding functions take as the second parameter one of the
3988 following rounding modes (R):
3989 'even', 'odd', '+inf', '-inf', 'zero', 'trunc', 'common'
3990 * you can set/get the global R by using C<< Math::SomeClass->round_mode() >>
3991 or by setting C<< $Math::SomeClass::round_mode >>
3992 * after each operation, C<< $result->round() >> is called, and the result may
3993 eventually be rounded (that is, if A or P were set either locally,
3994 globally or as parameter to the operation)
3995 * to manually round a number, call C<< $x->round($A,$P,$round_mode); >>
3996 this will round the number by using the appropriate rounding function
3997 and then normalize it.
3998 * rounding modifies the local settings of the number:
4000 $x = Math::BigFloat->new(123.456);
4004 Here 4 takes precedence over 5, so 123.5 is the result and $x->accuracy()
4005 will be 4 from now on.
4007 =item Default values
4016 * The defaults are set up so that the new code gives the same results as
4017 the old code (except in a few cases on fdiv):
4018 + Both A and P are undefined and thus will not be used for rounding
4019 after each operation.
4020 + round() is thus a no-op, unless given extra parameters A and P
4024 =head1 Infinity and Not a Number
4026 While BigInt has extensive handling of inf and NaN, certain quirks remain.
4032 These perl routines currently (as of Perl v.5.8.6) cannot handle passed
4035 te@linux:~> perl -wle 'print 2 ** 3333'
4037 te@linux:~> perl -wle 'print 2 ** 3333 == 2 ** 3333'
4039 te@linux:~> perl -wle 'print oct(2 ** 3333)'
4041 te@linux:~> perl -wle 'print hex(2 ** 3333)'
4042 Illegal hexadecimal digit 'i' ignored at -e line 1.
4045 The same problems occur if you pass them Math::BigInt->binf() objects. Since
4046 overloading these routines is not possible, this cannot be fixed from BigInt.
4048 =item ==, !=, <, >, <=, >= with NaNs
4050 BigInt's bcmp() routine currently returns undef to signal that a NaN was
4051 involved in a comparison. However, the overload code turns that into
4052 either 1 or '' and thus operations like C<< NaN != NaN >> might return
4057 C<< log(-inf) >> is highly weird. Since log(-x)=pi*i+log(x), then
4058 log(-inf)=pi*i+inf. However, since the imaginary part is finite, the real
4059 infinity "overshadows" it, so the number might as well just be infinity.
4060 However, the result is a complex number, and since BigInt/BigFloat can only
4061 have real numbers as results, the result is NaN.
4063 =item exp(), cos(), sin(), atan2()
4065 These all might have problems handling infinity right.
4071 The actual numbers are stored as unsigned big integers (with seperate sign).
4073 You should neither care about nor depend on the internal representation; it
4074 might change without notice. Use B<ONLY> method calls like C<< $x->sign(); >>
4075 instead relying on the internal representation.
4079 Math with the numbers is done (by default) by a module called
4080 C<Math::BigInt::Calc>. This is equivalent to saying:
4082 use Math::BigInt lib => 'Calc';
4084 You can change this by using:
4086 use Math::BigInt lib => 'BitVect';
4088 The following would first try to find Math::BigInt::Foo, then
4089 Math::BigInt::Bar, and when this also fails, revert to Math::BigInt::Calc:
4091 use Math::BigInt lib => 'Foo,Math::BigInt::Bar';
4093 Since Math::BigInt::GMP is in almost all cases faster than Calc (especially in
4094 math involving really big numbers, where it is B<much> faster), and there is
4095 no penalty if Math::BigInt::GMP is not installed, it is a good idea to always
4098 use Math::BigInt lib => 'GMP';
4100 Different low-level libraries use different formats to store the
4101 numbers. You should B<NOT> depend on the number having a specific format
4104 See the respective math library module documentation for further details.
4108 The sign is either '+', '-', 'NaN', '+inf' or '-inf'.
4110 A sign of 'NaN' is used to represent the result when input arguments are not
4111 numbers or as a result of 0/0. '+inf' and '-inf' represent plus respectively
4112 minus infinity. You will get '+inf' when dividing a positive number by 0, and
4113 '-inf' when dividing any negative number by 0.
4115 =head2 mantissa(), exponent() and parts()
4117 C<mantissa()> and C<exponent()> return the said parts of the BigInt such
4120 $m = $x->mantissa();
4121 $e = $x->exponent();
4122 $y = $m * ( 10 ** $e );
4123 print "ok\n" if $x == $y;
4125 C<< ($m,$e) = $x->parts() >> is just a shortcut that gives you both of them
4126 in one go. Both the returned mantissa and exponent have a sign.
4128 Currently, for BigInts C<$e> is always 0, except +inf and -inf, where it is
4129 C<+inf>; and for NaN, where it is C<NaN>; and for C<$x == 0>, where it is C<1>
4130 (to be compatible with Math::BigFloat's internal representation of a zero as
4133 C<$m> is currently just a copy of the original number. The relation between
4134 C<$e> and C<$m> will stay always the same, though their real values might
4141 sub bint { Math::BigInt->new(shift); }
4143 $x = Math::BigInt->bstr("1234") # string "1234"
4144 $x = "$x"; # same as bstr()
4145 $x = Math::BigInt->bneg("1234"); # BigInt "-1234"
4146 $x = Math::BigInt->babs("-12345"); # BigInt "12345"
4147 $x = Math::BigInt->bnorm("-0.00"); # BigInt "0"
4148 $x = bint(1) + bint(2); # BigInt "3"
4149 $x = bint(1) + "2"; # ditto (auto-BigIntify of "2")
4150 $x = bint(1); # BigInt "1"
4151 $x = $x + 5 / 2; # BigInt "3"
4152 $x = $x ** 3; # BigInt "27"
4153 $x *= 2; # BigInt "54"
4154 $x = Math::BigInt->new(0); # BigInt "0"
4156 $x = Math::BigInt->badd(4,5) # BigInt "9"
4157 print $x->bsstr(); # 9e+0
4159 Examples for rounding:
4164 $x = Math::BigFloat->new(123.4567);
4165 $y = Math::BigFloat->new(123.456789);
4166 Math::BigFloat->accuracy(4); # no more A than 4
4168 ok ($x->copy()->fround(),123.4); # even rounding
4169 print $x->copy()->fround(),"\n"; # 123.4
4170 Math::BigFloat->round_mode('odd'); # round to odd
4171 print $x->copy()->fround(),"\n"; # 123.5
4172 Math::BigFloat->accuracy(5); # no more A than 5
4173 Math::BigFloat->round_mode('odd'); # round to odd
4174 print $x->copy()->fround(),"\n"; # 123.46
4175 $y = $x->copy()->fround(4),"\n"; # A = 4: 123.4
4176 print "$y, ",$y->accuracy(),"\n"; # 123.4, 4
4178 Math::BigFloat->accuracy(undef); # A not important now
4179 Math::BigFloat->precision(2); # P important
4180 print $x->copy()->bnorm(),"\n"; # 123.46
4181 print $x->copy()->fround(),"\n"; # 123.46
4183 Examples for converting:
4185 my $x = Math::BigInt->new('0b1'.'01' x 123);
4186 print "bin: ",$x->as_bin()," hex:",$x->as_hex()," dec: ",$x,"\n";
4188 =head1 Autocreating constants
4190 After C<use Math::BigInt ':constant'> all the B<integer> decimal, hexadecimal
4191 and binary constants in the given scope are converted to C<Math::BigInt>.
4192 This conversion happens at compile time.
4196 perl -MMath::BigInt=:constant -e 'print 2**100,"\n"'
4198 prints the integer value of C<2**100>. Note that without conversion of
4199 constants the expression 2**100 will be calculated as perl scalar.
4201 Please note that strings and floating point constants are not affected,
4204 use Math::BigInt qw/:constant/;
4206 $x = 1234567890123456789012345678901234567890
4207 + 123456789123456789;
4208 $y = '1234567890123456789012345678901234567890'
4209 + '123456789123456789';
4211 do not work. You need an explicit Math::BigInt->new() around one of the
4212 operands. You should also quote large constants to protect loss of precision:
4216 $x = Math::BigInt->new('1234567889123456789123456789123456789');
4218 Without the quotes Perl would convert the large number to a floating point
4219 constant at compile time and then hand the result to BigInt, which results in
4220 an truncated result or a NaN.
4222 This also applies to integers that look like floating point constants:
4224 use Math::BigInt ':constant';
4226 print ref(123e2),"\n";
4227 print ref(123.2e2),"\n";
4229 will print nothing but newlines. Use either L<bignum> or L<Math::BigFloat>
4230 to get this to work.
4234 Using the form $x += $y; etc over $x = $x + $y is faster, since a copy of $x
4235 must be made in the second case. For long numbers, the copy can eat up to 20%
4236 of the work (in the case of addition/subtraction, less for
4237 multiplication/division). If $y is very small compared to $x, the form
4238 $x += $y is MUCH faster than $x = $x + $y since making the copy of $x takes
4239 more time then the actual addition.
4241 With a technique called copy-on-write, the cost of copying with overload could
4242 be minimized or even completely avoided. A test implementation of COW did show
4243 performance gains for overloaded math, but introduced a performance loss due
4244 to a constant overhead for all other operations. So Math::BigInt does currently
4247 The rewritten version of this module (vs. v0.01) is slower on certain
4248 operations, like C<new()>, C<bstr()> and C<numify()>. The reason are that it
4249 does now more work and handles much more cases. The time spent in these
4250 operations is usually gained in the other math operations so that code on
4251 the average should get (much) faster. If they don't, please contact the author.
4253 Some operations may be slower for small numbers, but are significantly faster
4254 for big numbers. Other operations are now constant (O(1), like C<bneg()>,
4255 C<babs()> etc), instead of O(N) and thus nearly always take much less time.
4256 These optimizations were done on purpose.
4258 If you find the Calc module to slow, try to install any of the replacement
4259 modules and see if they help you.
4261 =head2 Alternative math libraries
4263 You can use an alternative library to drive Math::BigInt via:
4265 use Math::BigInt lib => 'Module';
4267 See L<MATH LIBRARY> for more information.
4269 For more benchmark results see L<http://bloodgate.com/perl/benchmarks.html>.
4273 =head1 Subclassing Math::BigInt
4275 The basic design of Math::BigInt allows simple subclasses with very little
4276 work, as long as a few simple rules are followed:
4282 The public API must remain consistent, i.e. if a sub-class is overloading
4283 addition, the sub-class must use the same name, in this case badd(). The
4284 reason for this is that Math::BigInt is optimized to call the object methods
4289 The private object hash keys like C<$x->{sign}> may not be changed, but
4290 additional keys can be added, like C<$x->{_custom}>.
4294 Accessor functions are available for all existing object hash keys and should
4295 be used instead of directly accessing the internal hash keys. The reason for
4296 this is that Math::BigInt itself has a pluggable interface which permits it
4297 to support different storage methods.
4301 More complex sub-classes may have to replicate more of the logic internal of
4302 Math::BigInt if they need to change more basic behaviors. A subclass that
4303 needs to merely change the output only needs to overload C<bstr()>.
4305 All other object methods and overloaded functions can be directly inherited
4306 from the parent class.
4308 At the very minimum, any subclass will need to provide it's own C<new()> and can
4309 store additional hash keys in the object. There are also some package globals
4310 that must be defined, e.g.:
4314 $precision = -2; # round to 2 decimal places
4315 $round_mode = 'even';
4318 Additionally, you might want to provide the following two globals to allow
4319 auto-upgrading and auto-downgrading to work correctly:
4324 This allows Math::BigInt to correctly retrieve package globals from the
4325 subclass, like C<$SubClass::precision>. See t/Math/BigInt/Subclass.pm or
4326 t/Math/BigFloat/SubClass.pm completely functional subclass examples.
4332 in your subclass to automatically inherit the overloading from the parent. If
4333 you like, you can change part of the overloading, look at Math::String for an
4338 When used like this:
4340 use Math::BigInt upgrade => 'Foo::Bar';
4342 certain operations will 'upgrade' their calculation and thus the result to
4343 the class Foo::Bar. Usually this is used in conjunction with Math::BigFloat:
4345 use Math::BigInt upgrade => 'Math::BigFloat';
4347 As a shortcut, you can use the module C<bignum>:
4351 Also good for oneliners:
4353 perl -Mbignum -le 'print 2 ** 255'
4355 This makes it possible to mix arguments of different classes (as in 2.5 + 2)
4356 as well es preserve accuracy (as in sqrt(3)).
4358 Beware: This feature is not fully implemented yet.
4362 The following methods upgrade themselves unconditionally; that is if upgrade
4363 is in effect, they will always hand up their work:
4377 Beware: This list is not complete.
4379 All other methods upgrade themselves only when one (or all) of their
4380 arguments are of the class mentioned in $upgrade (This might change in later
4381 versions to a more sophisticated scheme):
4387 =item broot() does not work
4389 The broot() function in BigInt may only work for small values. This will be
4390 fixed in a later version.
4392 =item Out of Memory!
4394 Under Perl prior to 5.6.0 having an C<use Math::BigInt ':constant';> and
4395 C<eval()> in your code will crash with "Out of memory". This is probably an
4396 overload/exporter bug. You can workaround by not having C<eval()>
4397 and ':constant' at the same time or upgrade your Perl to a newer version.
4399 =item Fails to load Calc on Perl prior 5.6.0
4401 Since eval(' use ...') can not be used in conjunction with ':constant', BigInt
4402 will fall back to eval { require ... } when loading the math lib on Perls
4403 prior to 5.6.0. This simple replaces '::' with '/' and thus might fail on
4404 filesystems using a different seperator.
4410 Some things might not work as you expect them. Below is documented what is
4411 known to be troublesome:
4415 =item bstr(), bsstr() and 'cmp'
4417 Both C<bstr()> and C<bsstr()> as well as automated stringify via overload now
4418 drop the leading '+'. The old code would return '+3', the new returns '3'.
4419 This is to be consistent with Perl and to make C<cmp> (especially with
4420 overloading) to work as you expect. It also solves problems with C<Test.pm>,
4421 because it's C<ok()> uses 'eq' internally.
4423 Mark Biggar said, when asked about to drop the '+' altogether, or make only
4426 I agree (with the first alternative), don't add the '+' on positive
4427 numbers. It's not as important anymore with the new internal
4428 form for numbers. It made doing things like abs and neg easier,
4429 but those have to be done differently now anyway.
4431 So, the following examples will now work all as expected:
4434 BEGIN { plan tests => 1 }
4437 my $x = new Math::BigInt 3*3;
4438 my $y = new Math::BigInt 3*3;
4441 print "$x eq 9" if $x eq $y;
4442 print "$x eq 9" if $x eq '9';
4443 print "$x eq 9" if $x eq 3*3;
4445 Additionally, the following still works:
4447 print "$x == 9" if $x == $y;
4448 print "$x == 9" if $x == 9;
4449 print "$x == 9" if $x == 3*3;
4451 There is now a C<bsstr()> method to get the string in scientific notation aka
4452 C<1e+2> instead of C<100>. Be advised that overloaded 'eq' always uses bstr()
4453 for comparison, but Perl will represent some numbers as 100 and others
4454 as 1e+308. If in doubt, convert both arguments to Math::BigInt before
4455 comparing them as strings:
4458 BEGIN { plan tests => 3 }
4461 $x = Math::BigInt->new('1e56'); $y = 1e56;
4462 ok ($x,$y); # will fail
4463 ok ($x->bsstr(),$y); # okay
4464 $y = Math::BigInt->new($y);
4467 Alternatively, simple use C<< <=> >> for comparisons, this will get it
4468 always right. There is not yet a way to get a number automatically represented
4469 as a string that matches exactly the way Perl represents it.
4471 See also the section about L<Infinity and Not a Number> for problems in
4476 C<int()> will return (at least for Perl v5.7.1 and up) another BigInt, not a
4479 $x = Math::BigInt->new(123);
4480 $y = int($x); # BigInt 123
4481 $x = Math::BigFloat->new(123.45);
4482 $y = int($x); # BigInt 123
4484 In all Perl versions you can use C<as_number()> or C<as_int> for the same
4487 $x = Math::BigFloat->new(123.45);
4488 $y = $x->as_number(); # BigInt 123
4489 $y = $x->as_int(); # ditto
4491 This also works for other subclasses, like Math::String.
4493 If you want a real Perl scalar, use C<numify()>:
4495 $y = $x->numify(); # 123 as scalar
4497 This is seldom necessary, though, because this is done automatically, like
4498 when you access an array:
4500 $z = $array[$x]; # does work automatically
4504 The following will probably not do what you expect:
4506 $c = Math::BigInt->new(123);
4507 print $c->length(),"\n"; # prints 30
4509 It prints both the number of digits in the number and in the fraction part
4510 since print calls C<length()> in list context. Use something like:
4512 print scalar $c->length(),"\n"; # prints 3
4516 The following will probably not do what you expect:
4518 print $c->bdiv(10000),"\n";
4520 It prints both quotient and remainder since print calls C<bdiv()> in list
4521 context. Also, C<bdiv()> will modify $c, so be careful. You probably want
4524 print $c / 10000,"\n";
4525 print scalar $c->bdiv(10000),"\n"; # or if you want to modify $c
4529 The quotient is always the greatest integer less than or equal to the
4530 real-valued quotient of the two operands, and the remainder (when it is
4531 nonzero) always has the same sign as the second operand; so, for
4541 As a consequence, the behavior of the operator % agrees with the
4542 behavior of Perl's built-in % operator (as documented in the perlop
4543 manpage), and the equation
4545 $x == ($x / $y) * $y + ($x % $y)
4547 holds true for any $x and $y, which justifies calling the two return
4548 values of bdiv() the quotient and remainder. The only exception to this rule
4549 are when $y == 0 and $x is negative, then the remainder will also be
4550 negative. See below under "infinity handling" for the reasoning behind this.
4552 Perl's 'use integer;' changes the behaviour of % and / for scalars, but will
4553 not change BigInt's way to do things. This is because under 'use integer' Perl
4554 will do what the underlying C thinks is right and this is different for each
4555 system. If you need BigInt's behaving exactly like Perl's 'use integer', bug
4556 the author to implement it ;)
4558 =item infinity handling
4560 Here are some examples that explain the reasons why certain results occur while
4563 The following table shows the result of the division and the remainder, so that
4564 the equation above holds true. Some "ordinary" cases are strewn in to show more
4565 clearly the reasoning:
4567 A / B = C, R so that C * B + R = A
4568 =========================================================
4569 5 / 8 = 0, 5 0 * 8 + 5 = 5
4570 0 / 8 = 0, 0 0 * 8 + 0 = 0
4571 0 / inf = 0, 0 0 * inf + 0 = 0
4572 0 /-inf = 0, 0 0 * -inf + 0 = 0
4573 5 / inf = 0, 5 0 * inf + 5 = 5
4574 5 /-inf = 0, 5 0 * -inf + 5 = 5
4575 -5/ inf = 0, -5 0 * inf + -5 = -5
4576 -5/-inf = 0, -5 0 * -inf + -5 = -5
4577 inf/ 5 = inf, 0 inf * 5 + 0 = inf
4578 -inf/ 5 = -inf, 0 -inf * 5 + 0 = -inf
4579 inf/ -5 = -inf, 0 -inf * -5 + 0 = inf
4580 -inf/ -5 = inf, 0 inf * -5 + 0 = -inf
4581 5/ 5 = 1, 0 1 * 5 + 0 = 5
4582 -5/ -5 = 1, 0 1 * -5 + 0 = -5
4583 inf/ inf = 1, 0 1 * inf + 0 = inf
4584 -inf/-inf = 1, 0 1 * -inf + 0 = -inf
4585 inf/-inf = -1, 0 -1 * -inf + 0 = inf
4586 -inf/ inf = -1, 0 1 * -inf + 0 = -inf
4587 8/ 0 = inf, 8 inf * 0 + 8 = 8
4588 inf/ 0 = inf, inf inf * 0 + inf = inf
4591 These cases below violate the "remainder has the sign of the second of the two
4592 arguments", since they wouldn't match up otherwise.
4594 A / B = C, R so that C * B + R = A
4595 ========================================================
4596 -inf/ 0 = -inf, -inf -inf * 0 + inf = -inf
4597 -8/ 0 = -inf, -8 -inf * 0 + 8 = -8
4599 =item Modifying and =
4603 $x = Math::BigFloat->new(5);
4606 It will not do what you think, e.g. making a copy of $x. Instead it just makes
4607 a second reference to the B<same> object and stores it in $y. Thus anything
4608 that modifies $x (except overloaded operators) will modify $y, and vice versa.
4609 Or in other words, C<=> is only safe if you modify your BigInts only via
4610 overloaded math. As soon as you use a method call it breaks:
4613 print "$x, $y\n"; # prints '10, 10'
4615 If you want a true copy of $x, use:
4619 You can also chain the calls like this, this will make first a copy and then
4622 $y = $x->copy()->bmul(2);
4624 See also the documentation for overload.pm regarding C<=>.
4628 C<bpow()> (and the rounding functions) now modifies the first argument and
4629 returns it, unlike the old code which left it alone and only returned the
4630 result. This is to be consistent with C<badd()> etc. The first three will
4631 modify $x, the last one won't:
4633 print bpow($x,$i),"\n"; # modify $x
4634 print $x->bpow($i),"\n"; # ditto
4635 print $x **= $i,"\n"; # the same
4636 print $x ** $i,"\n"; # leave $x alone
4638 The form C<$x **= $y> is faster than C<$x = $x ** $y;>, though.
4640 =item Overloading -$x
4650 since overload calls C<sub($x,0,1);> instead of C<neg($x)>. The first variant
4651 needs to preserve $x since it does not know that it later will get overwritten.
4652 This makes a copy of $x and takes O(N), but $x->bneg() is O(1).
4654 =item Mixing different object types
4656 In Perl you will get a floating point value if you do one of the following:
4662 With overloaded math, only the first two variants will result in a BigFloat:
4667 $mbf = Math::BigFloat->new(5);
4668 $mbi2 = Math::BigInteger->new(5);
4669 $mbi = Math::BigInteger->new(2);
4671 # what actually gets called:
4672 $float = $mbf + $mbi; # $mbf->badd()
4673 $float = $mbf / $mbi; # $mbf->bdiv()
4674 $integer = $mbi + $mbf; # $mbi->badd()
4675 $integer = $mbi2 / $mbi; # $mbi2->bdiv()
4676 $integer = $mbi2 / $mbf; # $mbi2->bdiv()
4678 This is because math with overloaded operators follows the first (dominating)
4679 operand, and the operation of that is called and returns thus the result. So,
4680 Math::BigInt::bdiv() will always return a Math::BigInt, regardless whether
4681 the result should be a Math::BigFloat or the second operant is one.
4683 To get a Math::BigFloat you either need to call the operation manually,
4684 make sure the operands are already of the proper type or casted to that type
4685 via Math::BigFloat->new():
4687 $float = Math::BigFloat->new($mbi2) / $mbi; # = 2.5
4689 Beware of simple "casting" the entire expression, this would only convert
4690 the already computed result:
4692 $float = Math::BigFloat->new($mbi2 / $mbi); # = 2.0 thus wrong!
4694 Beware also of the order of more complicated expressions like:
4696 $integer = ($mbi2 + $mbi) / $mbf; # int / float => int
4697 $integer = $mbi2 / Math::BigFloat->new($mbi); # ditto
4699 If in doubt, break the expression into simpler terms, or cast all operands
4700 to the desired resulting type.
4702 Scalar values are a bit different, since:
4707 will both result in the proper type due to the way the overloaded math works.
4709 This section also applies to other overloaded math packages, like Math::String.
4711 One solution to you problem might be autoupgrading|upgrading. See the
4712 pragmas L<bignum>, L<bigint> and L<bigrat> for an easy way to do this.
4716 C<bsqrt()> works only good if the result is a big integer, e.g. the square
4717 root of 144 is 12, but from 12 the square root is 3, regardless of rounding
4718 mode. The reason is that the result is always truncated to an integer.
4720 If you want a better approximation of the square root, then use:
4722 $x = Math::BigFloat->new(12);
4723 Math::BigFloat->precision(0);
4724 Math::BigFloat->round_mode('even');
4725 print $x->copy->bsqrt(),"\n"; # 4
4727 Math::BigFloat->precision(2);
4728 print $x->bsqrt(),"\n"; # 3.46
4729 print $x->bsqrt(3),"\n"; # 3.464
4733 For negative numbers in base see also L<brsft|brsft>.
4739 This program is free software; you may redistribute it and/or modify it under
4740 the same terms as Perl itself.
4744 L<Math::BigFloat>, L<Math::BigRat> and L<Math::Big> as well as
4745 L<Math::BigInt::BitVect>, L<Math::BigInt::Pari> and L<Math::BigInt::GMP>.
4747 The pragmas L<bignum>, L<bigint> and L<bigrat> also might be of interest
4748 because they solve the autoupgrading/downgrading issue, at least partly.
4751 L<http://search.cpan.org/search?mode=module&query=Math%3A%3ABigInt> contains
4752 more documentation including a full version history, testcases, empty
4753 subclass files and benchmarks.
4757 Original code by Mark Biggar, overloaded interface by Ilya Zakharevich.
4758 Completely rewritten by Tels http://bloodgate.com in late 2000, 2001 - 2006
4759 and still at it in 2007.
4761 Many people contributed in one or more ways to the final beast, see the file
4762 CREDITS for an (incomplete) list. If you miss your name, please drop me a