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 # we might need '==' and '!=' to get things like "NaN == NaN" right
66 '<=>' => sub { $_[2] ?
67 ref($_[0])->bcmp($_[1],$_[0]) :
68 $_[0]->bcmp($_[1]); },
71 "$_[1]" cmp $_[0]->bstr() :
72 $_[0]->bstr() cmp "$_[1]" },
74 # make cos()/sin()/exp() "work" with BigInt's or subclasses
75 'cos' => sub { cos($_[0]->numify()) },
76 'sin' => sub { sin($_[0]->numify()) },
77 'exp' => sub { exp($_[0]->numify()) },
78 'atan2' => sub { $_[2] ?
79 atan2($_[1],$_[0]->numify()) :
80 atan2($_[0]->numify(),$_[1]) },
82 # are not yet overloadable
83 #'hex' => sub { print "hex"; $_[0]; },
84 #'oct' => sub { print "oct"; $_[0]; },
86 'log' => sub { $_[0]->copy()->blog($_[1]); },
87 'int' => sub { $_[0]->copy(); },
88 'neg' => sub { $_[0]->copy()->bneg(); },
89 'abs' => sub { $_[0]->copy()->babs(); },
90 'sqrt' => sub { $_[0]->copy()->bsqrt(); },
91 '~' => sub { $_[0]->copy()->bnot(); },
93 # for subtract it's a bit tricky to not modify b: b-a => -a+b
94 '-' => sub { my $c = $_[0]->copy; $_[2] ?
95 $c->bneg()->badd( $_[1]) :
97 '+' => sub { $_[0]->copy()->badd($_[1]); },
98 '*' => sub { $_[0]->copy()->bmul($_[1]); },
101 $_[2] ? ref($_[0])->new($_[1])->bdiv($_[0]) : $_[0]->copy->bdiv($_[1]);
104 $_[2] ? ref($_[0])->new($_[1])->bmod($_[0]) : $_[0]->copy->bmod($_[1]);
107 $_[2] ? ref($_[0])->new($_[1])->bpow($_[0]) : $_[0]->copy->bpow($_[1]);
110 $_[2] ? ref($_[0])->new($_[1])->blsft($_[0]) : $_[0]->copy->blsft($_[1]);
113 $_[2] ? ref($_[0])->new($_[1])->brsft($_[0]) : $_[0]->copy->brsft($_[1]);
116 $_[2] ? ref($_[0])->new($_[1])->band($_[0]) : $_[0]->copy->band($_[1]);
119 $_[2] ? ref($_[0])->new($_[1])->bior($_[0]) : $_[0]->copy->bior($_[1]);
122 $_[2] ? ref($_[0])->new($_[1])->bxor($_[0]) : $_[0]->copy->bxor($_[1]);
125 # can modify arg of ++ and --, so avoid a copy() for speed, but don't
126 # use $_[0]->bone(), it would modify $_[0] to be 1!
127 '++' => sub { $_[0]->binc() },
128 '--' => sub { $_[0]->bdec() },
130 # if overloaded, O(1) instead of O(N) and twice as fast for small numbers
132 # this kludge is needed for perl prior 5.6.0 since returning 0 here fails :-/
133 # v5.6.1 dumps on this: return !$_[0]->is_zero() || undef; :-(
135 $t = 1 if !$_[0]->is_zero();
139 # the original qw() does not work with the TIESCALAR below, why?
140 # Order of arguments unsignificant
141 '""' => sub { $_[0]->bstr(); },
142 '0+' => sub { $_[0]->numify(); }
145 ##############################################################################
146 # global constants, flags and accessory
148 # These vars are public, but their direct usage is not recommended, use the
149 # accessor methods instead
151 $round_mode = 'even'; # one of 'even', 'odd', '+inf', '-inf', 'zero', 'trunc' or 'common'
156 $upgrade = undef; # default is no upgrade
157 $downgrade = undef; # default is no downgrade
159 # These are internally, and not to be used from the outside at all
161 $_trap_nan = 0; # are NaNs ok? set w/ config()
162 $_trap_inf = 0; # are infs ok? set w/ config()
163 my $nan = 'NaN'; # constants for easier life
165 my $CALC = 'Math::BigInt::FastCalc'; # module to do the low level math
166 # default is FastCalc.pm
167 my $IMPORT = 0; # was import() called yet?
168 # used to make require work
169 my %WARN; # warn only once for low-level libs
170 my %CAN; # cache for $CALC->can(...)
171 my %CALLBACKS; # callbacks to notify on lib loads
172 my $EMU_LIB = 'Math/BigInt/CalcEmu.pm'; # emulate low-level math
174 ##############################################################################
175 # the old code had $rnd_mode, so we need to support it, too
178 sub TIESCALAR { my ($class) = @_; bless \$round_mode, $class; }
179 sub FETCH { return $round_mode; }
180 sub STORE { $rnd_mode = $_[0]->round_mode($_[1]); }
184 # tie to enable $rnd_mode to work transparently
185 tie $rnd_mode, 'Math::BigInt';
187 # set up some handy alias names
188 *as_int = \&as_number;
189 *is_pos = \&is_positive;
190 *is_neg = \&is_negative;
193 ##############################################################################
198 # make Class->round_mode() work
200 my $class = ref($self) || $self || __PACKAGE__;
204 if ($m !~ /^(even|odd|\+inf|\-inf|zero|trunc|common)$/)
206 require Carp; Carp::croak ("Unknown round mode '$m'");
208 return ${"${class}::round_mode"} = $m;
210 ${"${class}::round_mode"};
216 # make Class->upgrade() work
218 my $class = ref($self) || $self || __PACKAGE__;
219 # need to set new value?
222 return ${"${class}::upgrade"} = $_[0];
224 ${"${class}::upgrade"};
230 # make Class->downgrade() work
232 my $class = ref($self) || $self || __PACKAGE__;
233 # need to set new value?
236 return ${"${class}::downgrade"} = $_[0];
238 ${"${class}::downgrade"};
244 # make Class->div_scale() work
246 my $class = ref($self) || $self || __PACKAGE__;
251 require Carp; Carp::croak ('div_scale must be greater than zero');
253 ${"${class}::div_scale"} = $_[0];
255 ${"${class}::div_scale"};
260 # $x->accuracy($a); ref($x) $a
261 # $x->accuracy(); ref($x)
262 # Class->accuracy(); class
263 # Class->accuracy($a); class $a
266 my $class = ref($x) || $x || __PACKAGE__;
269 # need to set new value?
273 # convert objects to scalars to avoid deep recursion. If object doesn't
274 # have numify(), then hopefully it will have overloading for int() and
275 # boolean test without wandering into a deep recursion path...
276 $a = $a->numify() if ref($a) && $a->can('numify');
280 # also croak on non-numerical
284 Carp::croak ('Argument to accuracy must be greater than zero');
288 require Carp; Carp::croak ('Argument to accuracy must be an integer');
293 # $object->accuracy() or fallback to global
294 $x->bround($a) if $a; # not for undef, 0
295 $x->{_a} = $a; # set/overwrite, even if not rounded
296 delete $x->{_p}; # clear P
297 $a = ${"${class}::accuracy"} unless defined $a; # proper return value
301 ${"${class}::accuracy"} = $a; # set global A
302 ${"${class}::precision"} = undef; # clear global P
304 return $a; # shortcut
308 # $object->accuracy() or fallback to global
309 $a = $x->{_a} if ref($x);
310 # but don't return global undef, when $x's accuracy is 0!
311 $a = ${"${class}::accuracy"} if !defined $a;
317 # $x->precision($p); ref($x) $p
318 # $x->precision(); ref($x)
319 # Class->precision(); class
320 # Class->precision($p); class $p
323 my $class = ref($x) || $x || __PACKAGE__;
329 # convert objects to scalars to avoid deep recursion. If object doesn't
330 # have numify(), then hopefully it will have overloading for int() and
331 # boolean test without wandering into a deep recursion path...
332 $p = $p->numify() if ref($p) && $p->can('numify');
333 if ((defined $p) && (int($p) != $p))
335 require Carp; Carp::croak ('Argument to precision must be an integer');
339 # $object->precision() or fallback to global
340 $x->bfround($p) if $p; # not for undef, 0
341 $x->{_p} = $p; # set/overwrite, even if not rounded
342 delete $x->{_a}; # clear A
343 $p = ${"${class}::precision"} unless defined $p; # proper return value
347 ${"${class}::precision"} = $p; # set global P
348 ${"${class}::accuracy"} = undef; # clear global A
350 return $p; # shortcut
354 # $object->precision() or fallback to global
355 $p = $x->{_p} if ref($x);
356 # but don't return global undef, when $x's precision is 0!
357 $p = ${"${class}::precision"} if !defined $p;
363 # return (or set) configuration data as hash ref
364 my $class = shift || 'Math::BigInt';
369 # try to set given options as arguments from hash
372 if (ref($args) ne 'HASH')
376 # these values can be "set"
380 upgrade downgrade precision accuracy round_mode div_scale/
383 $set_args->{$key} = $args->{$key} if exists $args->{$key};
384 delete $args->{$key};
389 Carp::croak ("Illegal key(s) '",
390 join("','",keys %$args),"' passed to $class\->config()");
392 foreach my $key (keys %$set_args)
394 if ($key =~ /^trap_(inf|nan)\z/)
396 ${"${class}::_trap_$1"} = ($set_args->{"trap_$1"} ? 1 : 0);
399 # use a call instead of just setting the $variable to check argument
400 $class->$key($set_args->{$key});
404 # now return actual configuration
408 lib_version => ${"${CALC}::VERSION"},
410 trap_nan => ${"${class}::_trap_nan"},
411 trap_inf => ${"${class}::_trap_inf"},
412 version => ${"${class}::VERSION"},
415 upgrade downgrade precision accuracy round_mode div_scale
418 $cfg->{$key} = ${"${class}::$key"};
425 # select accuracy parameter based on precedence,
426 # used by bround() and bfround(), may return undef for scale (means no op)
427 my ($x,$scale,$mode) = @_;
429 $scale = $x->{_a} unless defined $scale;
434 $scale = ${ $class . '::accuracy' } unless defined $scale;
435 $mode = ${ $class . '::round_mode' } unless defined $mode;
442 # select precision parameter based on precedence,
443 # used by bround() and bfround(), may return undef for scale (means no op)
444 my ($x,$scale,$mode) = @_;
446 $scale = $x->{_p} unless defined $scale;
451 $scale = ${ $class . '::precision' } unless defined $scale;
452 $mode = ${ $class . '::round_mode' } unless defined $mode;
457 ##############################################################################
465 # if two arguments, the first one is the class to "swallow" subclasses
473 return unless ref($x); # only for objects
475 my $self = bless {}, $c;
477 $self->{sign} = $x->{sign};
478 $self->{value} = $CALC->_copy($x->{value});
479 $self->{_a} = $x->{_a} if defined $x->{_a};
480 $self->{_p} = $x->{_p} if defined $x->{_p};
486 # create a new BigInt object from a string or another BigInt object.
487 # see hash keys documented at top
489 # the argument could be an object, so avoid ||, && etc on it, this would
490 # cause costly overloaded code to be called. The only allowed ops are
493 my ($class,$wanted,$a,$p,$r) = @_;
495 # avoid numify-calls by not using || on $wanted!
496 return $class->bzero($a,$p) if !defined $wanted; # default to 0
497 return $class->copy($wanted,$a,$p,$r)
498 if ref($wanted) && $wanted->isa($class); # MBI or subclass
500 $class->import() if $IMPORT == 0; # make require work
502 my $self = bless {}, $class;
504 # shortcut for "normal" numbers
505 if ((!ref $wanted) && ($wanted =~ /^([+-]?)[1-9][0-9]*\z/))
507 $self->{sign} = $1 || '+';
509 if ($wanted =~ /^[+-]/)
511 # remove sign without touching wanted to make it work with constants
512 my $t = $wanted; $t =~ s/^[+-]//;
513 $self->{value} = $CALC->_new($t);
517 $self->{value} = $CALC->_new($wanted);
520 if ( (defined $a) || (defined $p)
521 || (defined ${"${class}::precision"})
522 || (defined ${"${class}::accuracy"})
525 $self->round($a,$p,$r) unless (@_ == 4 && !defined $a && !defined $p);
530 # handle '+inf', '-inf' first
531 if ($wanted =~ /^[+-]?inf\z/)
533 $self->{sign} = $wanted; # set a default sign for bstr()
534 return $self->binf($wanted);
536 # split str in m mantissa, e exponent, i integer, f fraction, v value, s sign
537 my ($mis,$miv,$mfv,$es,$ev) = _split($wanted);
542 require Carp; Carp::croak("$wanted is not a number in $class");
544 $self->{value} = $CALC->_zero();
545 $self->{sign} = $nan;
550 # _from_hex or _from_bin
551 $self->{value} = $mis->{value};
552 $self->{sign} = $mis->{sign};
553 return $self; # throw away $mis
555 # make integer from mantissa by adjusting exp, then convert to bigint
556 $self->{sign} = $$mis; # store sign
557 $self->{value} = $CALC->_zero(); # for all the NaN cases
558 my $e = int("$$es$$ev"); # exponent (avoid recursion)
561 my $diff = $e - CORE::length($$mfv);
562 if ($diff < 0) # Not integer
566 require Carp; Carp::croak("$wanted not an integer in $class");
569 return $upgrade->new($wanted,$a,$p,$r) if defined $upgrade;
570 $self->{sign} = $nan;
574 # adjust fraction and add it to value
575 #print "diff > 0 $$miv\n";
576 $$miv = $$miv . ($$mfv . '0' x $diff);
581 if ($$mfv ne '') # e <= 0
583 # fraction and negative/zero E => NOI
586 require Carp; Carp::croak("$wanted not an integer in $class");
588 #print "NOI 2 \$\$mfv '$$mfv'\n";
589 return $upgrade->new($wanted,$a,$p,$r) if defined $upgrade;
590 $self->{sign} = $nan;
594 # xE-y, and empty mfv
597 if ($$miv !~ s/0{$e}$//) # can strip so many zero's?
601 require Carp; Carp::croak("$wanted not an integer in $class");
604 return $upgrade->new($wanted,$a,$p,$r) if defined $upgrade;
605 $self->{sign} = $nan;
609 $self->{sign} = '+' if $$miv eq '0'; # normalize -0 => +0
610 $self->{value} = $CALC->_new($$miv) if $self->{sign} =~ /^[+-]$/;
611 # if any of the globals is set, use them to round and store them inside $self
612 # do not round for new($x,undef,undef) since that is used by MBF to signal
614 $self->round($a,$p,$r) unless @_ == 4 && !defined $a && !defined $p;
620 # create a bigint 'NaN', if given a BigInt, set it to 'NaN'
622 $self = $class if !defined $self;
625 my $c = $self; $self = {}; bless $self, $c;
628 if (${"${class}::_trap_nan"})
631 Carp::croak ("Tried to set $self to NaN in $class\::bnan()");
633 $self->import() if $IMPORT == 0; # make require work
634 return if $self->modify('bnan');
635 if ($self->can('_bnan'))
637 # use subclass to initialize
642 # otherwise do our own thing
643 $self->{value} = $CALC->_zero();
645 $self->{sign} = $nan;
646 delete $self->{_a}; delete $self->{_p}; # rounding NaN is silly
652 # create a bigint '+-inf', if given a BigInt, set it to '+-inf'
653 # the sign is either '+', or if given, used from there
655 my $sign = shift; $sign = '+' if !defined $sign || $sign !~ /^-(inf)?$/;
656 $self = $class if !defined $self;
659 my $c = $self; $self = {}; bless $self, $c;
662 if (${"${class}::_trap_inf"})
665 Carp::croak ("Tried to set $self to +-inf in $class\::binf()");
667 $self->import() if $IMPORT == 0; # make require work
668 return if $self->modify('binf');
669 if ($self->can('_binf'))
671 # use subclass to initialize
676 # otherwise do our own thing
677 $self->{value} = $CALC->_zero();
679 $sign = $sign . 'inf' if $sign !~ /inf$/; # - => -inf
680 $self->{sign} = $sign;
681 ($self->{_a},$self->{_p}) = @_; # take over requested rounding
687 # create a bigint '+0', if given a BigInt, set it to 0
689 $self = __PACKAGE__ if !defined $self;
693 my $c = $self; $self = {}; bless $self, $c;
695 $self->import() if $IMPORT == 0; # make require work
696 return if $self->modify('bzero');
698 if ($self->can('_bzero'))
700 # use subclass to initialize
705 # otherwise do our own thing
706 $self->{value} = $CALC->_zero();
713 # call like: $x->bzero($a,$p,$r,$y);
714 ($self,$self->{_a},$self->{_p}) = $self->_find_round_parameters(@_);
719 if ( (!defined $self->{_a}) || (defined $_[0] && $_[0] > $self->{_a}));
721 if ( (!defined $self->{_p}) || (defined $_[1] && $_[1] > $self->{_p}));
729 # create a bigint '+1' (or -1 if given sign '-'),
730 # if given a BigInt, set it to +1 or -1, respectively
732 my $sign = shift; $sign = '+' if !defined $sign || $sign ne '-';
733 $self = $class if !defined $self;
737 my $c = $self; $self = {}; bless $self, $c;
739 $self->import() if $IMPORT == 0; # make require work
740 return if $self->modify('bone');
742 if ($self->can('_bone'))
744 # use subclass to initialize
749 # otherwise do our own thing
750 $self->{value} = $CALC->_one();
752 $self->{sign} = $sign;
757 # call like: $x->bone($sign,$a,$p,$r,$y);
758 ($self,$self->{_a},$self->{_p}) = $self->_find_round_parameters(@_);
762 # call like: $x->bone($sign,$a,$p,$r);
764 if ( (!defined $self->{_a}) || (defined $_[0] && $_[0] > $self->{_a}));
766 if ( (!defined $self->{_p}) || (defined $_[1] && $_[1] > $self->{_p}));
772 ##############################################################################
773 # string conversation
777 # (ref to BFLOAT or num_str ) return num_str
778 # Convert number from internal format to scientific string format.
779 # internal format is always normalized (no leading zeros, "-0E0" => "+0E0")
780 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
782 if ($x->{sign} !~ /^[+-]$/)
784 return $x->{sign} unless $x->{sign} eq '+inf'; # -inf, NaN
787 my ($m,$e) = $x->parts();
788 #$m->bstr() . 'e+' . $e->bstr(); # e can only be positive in BigInt
789 # 'e+' because E can only be positive in BigInt
790 $m->bstr() . 'e+' . $CALC->_str($e->{value});
795 # make a string from bigint object
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 $es = ''; $es = $x->{sign} if $x->{sign} eq '-';
804 $es.$CALC->_str($x->{value});
809 # Make a "normal" scalar from a BigInt object
810 my $x = shift; $x = $class->new($x) unless ref $x;
812 return $x->bstr() if $x->{sign} !~ /^[+-]$/;
813 my $num = $CALC->_num($x->{value});
814 return -$num if $x->{sign} eq '-';
818 ##############################################################################
819 # public stuff (usually prefixed with "b")
823 # return the sign of the number: +/-/-inf/+inf/NaN
824 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
829 sub _find_round_parameters
831 # After any operation or when calling round(), the result is rounded by
832 # regarding the A & P from arguments, local parameters, or globals.
834 # !!!!!!! If you change this, remember to change round(), too! !!!!!!!!!!
836 # This procedure finds the round parameters, but it is for speed reasons
837 # duplicated in round. Otherwise, it is tested by the testsuite and used
840 # returns ($self) or ($self,$a,$p,$r) - sets $self to NaN of both A and P
841 # were requested/defined (locally or globally or both)
843 my ($self,$a,$p,$r,@args) = @_;
844 # $a accuracy, if given by caller
845 # $p precision, if given by caller
846 # $r round_mode, if given by caller
847 # @args all 'other' arguments (0 for unary, 1 for binary ops)
849 my $c = ref($self); # find out class of argument(s)
852 # now pick $a or $p, but only if we have got "arguments"
855 foreach ($self,@args)
857 # take the defined one, or if both defined, the one that is smaller
858 $a = $_->{_a} if (defined $_->{_a}) && (!defined $a || $_->{_a} < $a);
863 # even if $a is defined, take $p, to signal error for both defined
864 foreach ($self,@args)
866 # take the defined one, or if both defined, the one that is bigger
868 $p = $_->{_p} if (defined $_->{_p}) && (!defined $p || $_->{_p} > $p);
871 # if still none defined, use globals (#2)
872 $a = ${"$c\::accuracy"} unless defined $a;
873 $p = ${"$c\::precision"} unless defined $p;
875 # A == 0 is useless, so undef it to signal no rounding
876 $a = undef if defined $a && $a == 0;
879 return ($self) unless defined $a || defined $p; # early out
881 # set A and set P is an fatal error
882 return ($self->bnan()) if defined $a && defined $p; # error
884 $r = ${"$c\::round_mode"} unless defined $r;
885 if ($r !~ /^(even|odd|\+inf|\-inf|zero|trunc|common)$/)
887 require Carp; Carp::croak ("Unknown round mode '$r'");
895 # Round $self according to given parameters, or given second argument's
896 # parameters or global defaults
898 # for speed reasons, _find_round_parameters is embeded here:
900 my ($self,$a,$p,$r,@args) = @_;
901 # $a accuracy, if given by caller
902 # $p precision, if given by caller
903 # $r round_mode, if given by caller
904 # @args all 'other' arguments (0 for unary, 1 for binary ops)
906 my $c = ref($self); # find out class of argument(s)
909 # now pick $a or $p, but only if we have got "arguments"
912 foreach ($self,@args)
914 # take the defined one, or if both defined, the one that is smaller
915 $a = $_->{_a} if (defined $_->{_a}) && (!defined $a || $_->{_a} < $a);
920 # even if $a is defined, take $p, to signal error for both defined
921 foreach ($self,@args)
923 # take the defined one, or if both defined, the one that is bigger
925 $p = $_->{_p} if (defined $_->{_p}) && (!defined $p || $_->{_p} > $p);
928 # if still none defined, use globals (#2)
929 $a = ${"$c\::accuracy"} unless defined $a;
930 $p = ${"$c\::precision"} unless defined $p;
932 # A == 0 is useless, so undef it to signal no rounding
933 $a = undef if defined $a && $a == 0;
936 return $self unless defined $a || defined $p; # early out
938 # set A and set P is an fatal error
939 return $self->bnan() if defined $a && defined $p;
941 $r = ${"$c\::round_mode"} unless defined $r;
942 if ($r !~ /^(even|odd|\+inf|\-inf|zero|trunc|common)$/)
944 require Carp; Carp::croak ("Unknown round mode '$r'");
947 # now round, by calling either fround or ffround:
950 $self->bround($a,$r) if !defined $self->{_a} || $self->{_a} >= $a;
952 else # both can't be undefined due to early out
954 $self->bfround($p,$r) if !defined $self->{_p} || $self->{_p} <= $p;
956 # bround() or bfround() already callled bnorm() if nec.
962 # (numstr or BINT) return BINT
963 # Normalize number -- no-op here
964 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
970 # (BINT or num_str) return BINT
971 # make number absolute, or return absolute BINT from string
972 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
974 return $x if $x->modify('babs');
975 # post-normalized abs for internal use (does nothing for NaN)
976 $x->{sign} =~ s/^-/+/;
982 # (BINT or num_str) return BINT
983 # negate number or make a negated number from string
984 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
986 return $x if $x->modify('bneg');
988 # for +0 dont negate (to have always normalized +0). Does nothing for 'NaN'
989 $x->{sign} =~ tr/+-/-+/ unless ($x->{sign} eq '+' && $CALC->_is_zero($x->{value}));
995 # Compares 2 values. Returns one of undef, <0, =0, >0. (suitable for sort)
996 # (BINT or num_str, BINT or num_str) return cond_code
999 my ($self,$x,$y) = (ref($_[0]),@_);
1001 # objectify is costly, so avoid it
1002 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1004 ($self,$x,$y) = objectify(2,@_);
1007 return $upgrade->bcmp($x,$y) if defined $upgrade &&
1008 ((!$x->isa($self)) || (!$y->isa($self)));
1010 if (($x->{sign} !~ /^[+-]$/) || ($y->{sign} !~ /^[+-]$/))
1012 # handle +-inf and NaN
1013 return undef if (($x->{sign} eq $nan) || ($y->{sign} eq $nan));
1014 return 0 if $x->{sign} eq $y->{sign} && $x->{sign} =~ /^[+-]inf$/;
1015 return +1 if $x->{sign} eq '+inf';
1016 return -1 if $x->{sign} eq '-inf';
1017 return -1 if $y->{sign} eq '+inf';
1020 # check sign for speed first
1021 return 1 if $x->{sign} eq '+' && $y->{sign} eq '-'; # does also 0 <=> -y
1022 return -1 if $x->{sign} eq '-' && $y->{sign} eq '+'; # does also -x <=> 0
1024 # have same sign, so compare absolute values. Don't make tests for zero here
1025 # because it's actually slower than testin in Calc (especially w/ Pari et al)
1027 # post-normalized compare for internal use (honors signs)
1028 if ($x->{sign} eq '+')
1030 # $x and $y both > 0
1031 return $CALC->_acmp($x->{value},$y->{value});
1035 $CALC->_acmp($y->{value},$x->{value}); # swaped acmp (lib returns 0,1,-1)
1040 # Compares 2 values, ignoring their signs.
1041 # Returns one of undef, <0, =0, >0. (suitable for sort)
1042 # (BINT, BINT) return cond_code
1045 my ($self,$x,$y) = (ref($_[0]),@_);
1046 # objectify is costly, so avoid it
1047 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1049 ($self,$x,$y) = objectify(2,@_);
1052 return $upgrade->bacmp($x,$y) if defined $upgrade &&
1053 ((!$x->isa($self)) || (!$y->isa($self)));
1055 if (($x->{sign} !~ /^[+-]$/) || ($y->{sign} !~ /^[+-]$/))
1057 # handle +-inf and NaN
1058 return undef if (($x->{sign} eq $nan) || ($y->{sign} eq $nan));
1059 return 0 if $x->{sign} =~ /^[+-]inf$/ && $y->{sign} =~ /^[+-]inf$/;
1060 return 1 if $x->{sign} =~ /^[+-]inf$/ && $y->{sign} !~ /^[+-]inf$/;
1063 $CALC->_acmp($x->{value},$y->{value}); # lib does only 0,1,-1
1068 # add second arg (BINT or string) to first (BINT) (modifies first)
1069 # return result as BINT
1072 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1073 # objectify is costly, so avoid it
1074 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1076 ($self,$x,$y,@r) = objectify(2,@_);
1079 return $x if $x->modify('badd');
1080 return $upgrade->badd($upgrade->new($x),$upgrade->new($y),@r) if defined $upgrade &&
1081 ((!$x->isa($self)) || (!$y->isa($self)));
1083 $r[3] = $y; # no push!
1084 # inf and NaN handling
1085 if (($x->{sign} !~ /^[+-]$/) || ($y->{sign} !~ /^[+-]$/))
1088 return $x->bnan() if (($x->{sign} eq $nan) || ($y->{sign} eq $nan));
1090 if (($x->{sign} =~ /^[+-]inf$/) && ($y->{sign} =~ /^[+-]inf$/))
1092 # +inf++inf or -inf+-inf => same, rest is NaN
1093 return $x if $x->{sign} eq $y->{sign};
1096 # +-inf + something => +inf
1097 # something +-inf => +-inf
1098 $x->{sign} = $y->{sign}, return $x if $y->{sign} =~ /^[+-]inf$/;
1102 my ($sx, $sy) = ( $x->{sign}, $y->{sign} ); # get signs
1106 $x->{value} = $CALC->_add($x->{value},$y->{value}); # same sign, abs add
1110 my $a = $CALC->_acmp ($y->{value},$x->{value}); # absolute compare
1113 $x->{value} = $CALC->_sub($y->{value},$x->{value},1); # abs sub w/ swap
1118 # speedup, if equal, set result to 0
1119 $x->{value} = $CALC->_zero();
1124 $x->{value} = $CALC->_sub($x->{value}, $y->{value}); # abs sub
1132 # (BINT or num_str, BINT or num_str) return BINT
1133 # subtract second arg from first, modify first
1136 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1137 # objectify is costly, so avoid it
1138 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1140 ($self,$x,$y,@r) = objectify(2,@_);
1143 return $x if $x->modify('bsub');
1145 return $upgrade->new($x)->bsub($upgrade->new($y),@r) if defined $upgrade &&
1146 ((!$x->isa($self)) || (!$y->isa($self)));
1148 return $x->round(@r) if $y->is_zero();
1150 # To correctly handle the lone special case $x->bsub($x), we note the sign
1151 # of $x, then flip the sign from $y, and if the sign of $x did change, too,
1152 # then we caught the special case:
1153 my $xsign = $x->{sign};
1154 $y->{sign} =~ tr/+\-/-+/; # does nothing for NaN
1155 if ($xsign ne $x->{sign})
1157 # special case of $x->bsub($x) results in 0
1158 return $x->bzero(@r) if $xsign =~ /^[+-]$/;
1159 return $x->bnan(); # NaN, -inf, +inf
1161 $x->badd($y,@r); # badd does not leave internal zeros
1162 $y->{sign} =~ tr/+\-/-+/; # refix $y (does nothing for NaN)
1163 $x; # already rounded by badd() or no round nec.
1168 # increment arg by one
1169 my ($self,$x,$a,$p,$r) = ref($_[0]) ? (ref($_[0]),@_) : objectify(1,@_);
1170 return $x if $x->modify('binc');
1172 if ($x->{sign} eq '+')
1174 $x->{value} = $CALC->_inc($x->{value});
1175 return $x->round($a,$p,$r);
1177 elsif ($x->{sign} eq '-')
1179 $x->{value} = $CALC->_dec($x->{value});
1180 $x->{sign} = '+' if $CALC->_is_zero($x->{value}); # -1 +1 => -0 => +0
1181 return $x->round($a,$p,$r);
1183 # inf, nan handling etc
1184 $x->badd($self->bone(),$a,$p,$r); # badd does round
1189 # decrement arg by one
1190 my ($self,$x,@r) = ref($_[0]) ? (ref($_[0]),@_) : objectify(1,@_);
1191 return $x if $x->modify('bdec');
1193 if ($x->{sign} eq '-')
1196 $x->{value} = $CALC->_inc($x->{value});
1200 return $x->badd($self->bone('-'),@r) unless $x->{sign} eq '+'; # inf or NaN
1202 if ($CALC->_is_zero($x->{value}))
1205 $x->{value} = $CALC->_one(); $x->{sign} = '-'; # 0 => -1
1210 $x->{value} = $CALC->_dec($x->{value});
1218 # calculate $x = $a ** $base + $b and return $a (e.g. the log() to base
1222 my ($self,$x,$base,@r) = (undef,@_);
1223 # objectify is costly, so avoid it
1224 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1226 ($self,$x,$base,@r) = objectify(1,ref($x),@_);
1229 return $x if $x->modify('blog');
1231 # inf, -inf, NaN, <0 => NaN
1233 if $x->{sign} ne '+' || (defined $base && $base->{sign} ne '+');
1235 return $upgrade->blog($upgrade->new($x),$base,@r) if
1238 my ($rc,$exact) = $CALC->_log_int($x->{value},$base->{value});
1239 return $x->bnan() unless defined $rc; # not possible to take log?
1246 # (BINT or num_str, BINT or num_str) return BINT
1247 # does not modify arguments, but returns new object
1248 # Lowest Common Multiplicator
1250 my $y = shift; my ($x);
1257 $x = $class->new($y);
1262 my $y = shift; $y = $self->new($y) if !ref ($y);
1270 # (BINT or num_str, BINT or num_str) return BINT
1271 # does not modify arguments, but returns new object
1272 # GCD -- Euclids algorithm, variant C (Knuth Vol 3, pg 341 ff)
1275 $y = $class->new($y) if !ref($y);
1277 my $x = $y->copy()->babs(); # keep arguments
1278 return $x->bnan() if $x->{sign} !~ /^[+-]$/; # x NaN?
1282 $y = shift; $y = $self->new($y) if !ref($y);
1283 return $x->bnan() if $y->{sign} !~ /^[+-]$/; # y NaN?
1284 $x->{value} = $CALC->_gcd($x->{value},$y->{value});
1285 last if $CALC->_is_one($x->{value});
1292 # (num_str or BINT) return BINT
1293 # represent ~x as twos-complement number
1294 # we don't need $self, so undef instead of ref($_[0]) make it slightly faster
1295 my ($self,$x,$a,$p,$r) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
1297 return $x if $x->modify('bnot');
1298 $x->binc()->bneg(); # binc already does round
1301 ##############################################################################
1302 # is_foo test routines
1303 # we don't need $self, so undef instead of ref($_[0]) make it slightly faster
1307 # return true if arg (BINT or num_str) is zero (array '+', '0')
1308 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1310 return 0 if $x->{sign} !~ /^\+$/; # -, NaN & +-inf aren't
1311 $CALC->_is_zero($x->{value});
1316 # return true if arg (BINT or num_str) is NaN
1317 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1319 $x->{sign} eq $nan ? 1 : 0;
1324 # return true if arg (BINT or num_str) is +-inf
1325 my ($self,$x,$sign) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
1329 $sign = '[+-]inf' if $sign eq ''; # +- doesn't matter, only that's inf
1330 $sign = "[$1]inf" if $sign =~ /^([+-])(inf)?$/; # extract '+' or '-'
1331 return $x->{sign} =~ /^$sign$/ ? 1 : 0;
1333 $x->{sign} =~ /^[+-]inf$/ ? 1 : 0; # only +-inf is infinity
1338 # return true if arg (BINT or num_str) is +1, or -1 if sign is given
1339 my ($self,$x,$sign) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
1341 $sign = '+' if !defined $sign || $sign ne '-';
1343 return 0 if $x->{sign} ne $sign; # -1 != +1, NaN, +-inf aren't either
1344 $CALC->_is_one($x->{value});
1349 # return true when arg (BINT or num_str) is odd, false for even
1350 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1352 return 0 if $x->{sign} !~ /^[+-]$/; # NaN & +-inf aren't
1353 $CALC->_is_odd($x->{value});
1358 # return true when arg (BINT or num_str) is even, false for odd
1359 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1361 return 0 if $x->{sign} !~ /^[+-]$/; # NaN & +-inf aren't
1362 $CALC->_is_even($x->{value});
1367 # return true when arg (BINT or num_str) is positive (>= 0)
1368 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1370 return 1 if $x->{sign} eq '+inf'; # +inf is positive
1372 # 0+ is neither positive nor negative
1373 ($x->{sign} eq '+' && !$x->is_zero()) ? 1 : 0;
1378 # return true when arg (BINT or num_str) is negative (< 0)
1379 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1381 $x->{sign} =~ /^-/ ? 1 : 0; # -inf is negative, but NaN is not
1386 # return true when arg (BINT or num_str) is an integer
1387 # always true for BigInt, but different for BigFloats
1388 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1390 $x->{sign} =~ /^[+-]$/ ? 1 : 0; # inf/-inf/NaN aren't
1393 ###############################################################################
1397 # multiply two numbers -- stolen from Knuth Vol 2 pg 233
1398 # (BINT or num_str, BINT or num_str) return BINT
1401 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1402 # objectify is costly, so avoid it
1403 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1405 ($self,$x,$y,@r) = objectify(2,@_);
1408 return $x if $x->modify('bmul');
1410 return $x->bnan() if (($x->{sign} eq $nan) || ($y->{sign} eq $nan));
1413 if (($x->{sign} =~ /^[+-]inf$/) || ($y->{sign} =~ /^[+-]inf$/))
1415 return $x->bnan() if $x->is_zero() || $y->is_zero();
1416 # result will always be +-inf:
1417 # +inf * +/+inf => +inf, -inf * -/-inf => +inf
1418 # +inf * -/-inf => -inf, -inf * +/+inf => -inf
1419 return $x->binf() if ($x->{sign} =~ /^\+/ && $y->{sign} =~ /^\+/);
1420 return $x->binf() if ($x->{sign} =~ /^-/ && $y->{sign} =~ /^-/);
1421 return $x->binf('-');
1424 return $upgrade->bmul($x,$upgrade->new($y),@r)
1425 if defined $upgrade && !$y->isa($self);
1427 $r[3] = $y; # no push here
1429 $x->{sign} = $x->{sign} eq $y->{sign} ? '+' : '-'; # +1 * +1 or -1 * -1 => +
1431 $x->{value} = $CALC->_mul($x->{value},$y->{value}); # do actual math
1432 $x->{sign} = '+' if $CALC->_is_zero($x->{value}); # no -0
1439 # helper function that handles +-inf cases for bdiv()/bmod() to reuse code
1440 my ($self,$x,$y) = @_;
1442 # NaN if x == NaN or y == NaN or x==y==0
1443 return wantarray ? ($x->bnan(),$self->bnan()) : $x->bnan()
1444 if (($x->is_nan() || $y->is_nan()) ||
1445 ($x->is_zero() && $y->is_zero()));
1447 # +-inf / +-inf == NaN, reminder also NaN
1448 if (($x->{sign} =~ /^[+-]inf$/) && ($y->{sign} =~ /^[+-]inf$/))
1450 return wantarray ? ($x->bnan(),$self->bnan()) : $x->bnan();
1452 # x / +-inf => 0, remainder x (works even if x == 0)
1453 if ($y->{sign} =~ /^[+-]inf$/)
1455 my $t = $x->copy(); # bzero clobbers up $x
1456 return wantarray ? ($x->bzero(),$t) : $x->bzero()
1459 # 5 / 0 => +inf, -6 / 0 => -inf
1460 # +inf / 0 = inf, inf, and -inf / 0 => -inf, -inf
1461 # exception: -8 / 0 has remainder -8, not 8
1462 # exception: -inf / 0 has remainder -inf, not inf
1465 # +-inf / 0 => special case for -inf
1466 return wantarray ? ($x,$x->copy()) : $x if $x->is_inf();
1467 if (!$x->is_zero() && !$x->is_inf())
1469 my $t = $x->copy(); # binf clobbers up $x
1471 ($x->binf($x->{sign}),$t) : $x->binf($x->{sign})
1475 # last case: +-inf / ordinary number
1477 $sign = '-inf' if substr($x->{sign},0,1) ne $y->{sign};
1479 return wantarray ? ($x,$self->bzero()) : $x;
1484 # (dividend: BINT or num_str, divisor: BINT or num_str) return
1485 # (BINT,BINT) (quo,rem) or BINT (only rem)
1488 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1489 # objectify is costly, so avoid it
1490 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1492 ($self,$x,$y,@r) = objectify(2,@_);
1495 return $x if $x->modify('bdiv');
1497 return $self->_div_inf($x,$y)
1498 if (($x->{sign} !~ /^[+-]$/) || ($y->{sign} !~ /^[+-]$/) || $y->is_zero());
1500 return $upgrade->bdiv($upgrade->new($x),$upgrade->new($y),@r)
1501 if defined $upgrade;
1503 $r[3] = $y; # no push!
1505 # calc new sign and in case $y == +/- 1, return $x
1506 my $xsign = $x->{sign}; # keep
1507 $x->{sign} = ($x->{sign} ne $y->{sign} ? '-' : '+');
1511 my $rem = $self->bzero();
1512 ($x->{value},$rem->{value}) = $CALC->_div($x->{value},$y->{value});
1513 $x->{sign} = '+' if $CALC->_is_zero($x->{value});
1514 $rem->{_a} = $x->{_a};
1515 $rem->{_p} = $x->{_p};
1517 if (! $CALC->_is_zero($rem->{value}))
1519 $rem->{sign} = $y->{sign};
1520 $rem = $y->copy()->bsub($rem) if $xsign ne $y->{sign}; # one of them '-'
1524 $rem->{sign} = '+'; # dont leave -0
1530 $x->{value} = $CALC->_div($x->{value},$y->{value});
1531 $x->{sign} = '+' if $CALC->_is_zero($x->{value});
1536 ###############################################################################
1541 # modulus (or remainder)
1542 # (BINT or num_str, BINT or num_str) return BINT
1545 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1546 # objectify is costly, so avoid it
1547 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1549 ($self,$x,$y,@r) = objectify(2,@_);
1552 return $x if $x->modify('bmod');
1553 $r[3] = $y; # no push!
1554 if (($x->{sign} !~ /^[+-]$/) || ($y->{sign} !~ /^[+-]$/) || $y->is_zero())
1556 my ($d,$r) = $self->_div_inf($x,$y);
1557 $x->{sign} = $r->{sign};
1558 $x->{value} = $r->{value};
1559 return $x->round(@r);
1562 # calc new sign and in case $y == +/- 1, return $x
1563 $x->{value} = $CALC->_mod($x->{value},$y->{value});
1564 if (!$CALC->_is_zero($x->{value}))
1566 $x->{value} = $CALC->_sub($y->{value},$x->{value},1) # $y-$x
1567 if ($x->{sign} ne $y->{sign});
1568 $x->{sign} = $y->{sign};
1572 $x->{sign} = '+'; # dont leave -0
1579 # Modular inverse. given a number which is (hopefully) relatively
1580 # prime to the modulus, calculate its inverse using Euclid's
1581 # alogrithm. If the number is not relatively prime to the modulus
1582 # (i.e. their gcd is not one) then NaN is returned.
1585 my ($self,$x,$y,@r) = (undef,@_);
1586 # objectify is costly, so avoid it
1587 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1589 ($self,$x,$y,@r) = objectify(2,@_);
1592 return $x if $x->modify('bmodinv');
1595 if ($y->{sign} ne '+' # -, NaN, +inf, -inf
1596 || $x->is_zero() # or num == 0
1597 || $x->{sign} !~ /^[+-]$/ # or num NaN, inf, -inf
1600 # put least residue into $x if $x was negative, and thus make it positive
1601 $x->bmod($y) if $x->{sign} eq '-';
1604 ($x->{value},$sign) = $CALC->_modinv($x->{value},$y->{value});
1605 return $x->bnan() if !defined $x->{value}; # in case no GCD found
1606 return $x if !defined $sign; # already real result
1607 $x->{sign} = $sign; # flip/flop see below
1608 $x->bmod($y); # calc real result
1614 # takes a very large number to a very large exponent in a given very
1615 # large modulus, quickly, thanks to binary exponentation. supports
1616 # negative exponents.
1617 my ($self,$num,$exp,$mod,@r) = objectify(3,@_);
1619 return $num if $num->modify('bmodpow');
1621 # check modulus for valid values
1622 return $num->bnan() if ($mod->{sign} ne '+' # NaN, - , -inf, +inf
1623 || $mod->is_zero());
1625 # check exponent for valid values
1626 if ($exp->{sign} =~ /\w/)
1628 # i.e., if it's NaN, +inf, or -inf...
1629 return $num->bnan();
1632 $num->bmodinv ($mod) if ($exp->{sign} eq '-');
1634 # check num for valid values (also NaN if there was no inverse but $exp < 0)
1635 return $num->bnan() if $num->{sign} !~ /^[+-]$/;
1637 # $mod is positive, sign on $exp is ignored, result also positive
1638 $num->{value} = $CALC->_modpow($num->{value},$exp->{value},$mod->{value});
1642 ###############################################################################
1646 # (BINT or num_str, BINT or num_str) return BINT
1647 # compute factorial number from $x, modify $x in place
1648 my ($self,$x,@r) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
1650 return $x if $x->modify('bfac') || $x->{sign} eq '+inf'; # inf => inf
1651 return $x->bnan() if $x->{sign} ne '+'; # NaN, <0 etc => NaN
1653 $x->{value} = $CALC->_fac($x->{value});
1659 # (BINT or num_str, BINT or num_str) return BINT
1660 # compute power of two numbers -- stolen from Knuth Vol 2 pg 233
1661 # modifies first argument
1664 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1665 # objectify is costly, so avoid it
1666 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1668 ($self,$x,$y,@r) = objectify(2,@_);
1671 return $x if $x->modify('bpow');
1673 return $x->bnan() if $x->{sign} eq $nan || $y->{sign} eq $nan;
1676 if (($x->{sign} =~ /^[+-]inf$/) || ($y->{sign} =~ /^[+-]inf$/))
1678 if (($x->{sign} =~ /^[+-]inf$/) && ($y->{sign} =~ /^[+-]inf$/))
1684 if ($x->{sign} =~ /^[+-]inf/)
1687 return $x->bnan() if $y->is_zero();
1688 # -inf ** -1 => 1/inf => 0
1689 return $x->bzero() if $y->is_one('-') && $x->is_negative();
1692 return $x if $x->{sign} eq '+inf';
1694 # -inf ** Y => -inf if Y is odd
1695 return $x if $y->is_odd();
1701 return $x if $x->is_one();
1704 return $x if $x->is_zero() && $y->{sign} =~ /^[+]/;
1707 return $x->binf() if $x->is_zero();
1710 return $x->bnan() if $x->is_one('-') && $y->{sign} =~ /^[-]/;
1713 return $x->bzero() if $x->{sign} eq '-' && $y->{sign} =~ /^[-]/;
1716 return $x->bnan() if $x->{sign} eq '-';
1719 return $x->binf() if $y->{sign} =~ /^[+]/;
1724 return $upgrade->bpow($upgrade->new($x),$y,@r)
1725 if defined $upgrade && (!$y->isa($self) || $y->{sign} eq '-');
1727 $r[3] = $y; # no push!
1729 # cases 0 ** Y, X ** 0, X ** 1, 1 ** Y are handled by Calc or Emu
1732 $new_sign = $y->is_odd() ? '-' : '+' if ($x->{sign} ne '+');
1734 # 0 ** -7 => ( 1 / (0 ** 7)) => 1 / 0 => +inf
1736 if $y->{sign} eq '-' && $x->{sign} eq '+' && $CALC->_is_zero($x->{value});
1737 # 1 ** -y => 1 / (1 ** |y|)
1738 # so do test for negative $y after above's clause
1739 return $x->bnan() if $y->{sign} eq '-' && !$CALC->_is_one($x->{value});
1741 $x->{value} = $CALC->_pow($x->{value},$y->{value});
1742 $x->{sign} = $new_sign;
1743 $x->{sign} = '+' if $CALC->_is_zero($y->{value});
1749 # (BINT or num_str, BINT or num_str) return BINT
1750 # compute x << y, base n, y >= 0
1753 my ($self,$x,$y,$n,@r) = (ref($_[0]),@_);
1754 # objectify is costly, so avoid it
1755 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1757 ($self,$x,$y,$n,@r) = objectify(2,@_);
1760 return $x if $x->modify('blsft');
1761 return $x->bnan() if ($x->{sign} !~ /^[+-]$/ || $y->{sign} !~ /^[+-]$/);
1762 return $x->round(@r) if $y->is_zero();
1764 $n = 2 if !defined $n; return $x->bnan() if $n <= 0 || $y->{sign} eq '-';
1766 $x->{value} = $CALC->_lsft($x->{value},$y->{value},$n);
1772 # (BINT or num_str, BINT or num_str) return BINT
1773 # compute x >> y, base n, y >= 0
1776 my ($self,$x,$y,$n,@r) = (ref($_[0]),@_);
1777 # objectify is costly, so avoid it
1778 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1780 ($self,$x,$y,$n,@r) = objectify(2,@_);
1783 return $x if $x->modify('brsft');
1784 return $x->bnan() if ($x->{sign} !~ /^[+-]$/ || $y->{sign} !~ /^[+-]$/);
1785 return $x->round(@r) if $y->is_zero();
1786 return $x->bzero(@r) if $x->is_zero(); # 0 => 0
1788 $n = 2 if !defined $n; return $x->bnan() if $n <= 0 || $y->{sign} eq '-';
1790 # this only works for negative numbers when shifting in base 2
1791 if (($x->{sign} eq '-') && ($n == 2))
1793 return $x->round(@r) if $x->is_one('-'); # -1 => -1
1796 # although this is O(N*N) in calc (as_bin!) it is O(N) in Pari et al
1797 # but perhaps there is a better emulation for two's complement shift...
1798 # if $y != 1, we must simulate it by doing:
1799 # convert to bin, flip all bits, shift, and be done
1800 $x->binc(); # -3 => -2
1801 my $bin = $x->as_bin();
1802 $bin =~ s/^-0b//; # strip '-0b' prefix
1803 $bin =~ tr/10/01/; # flip bits
1805 if (CORE::length($bin) <= $y)
1807 $bin = '0'; # shifting to far right creates -1
1808 # 0, because later increment makes
1809 # that 1, attached '-' makes it '-1'
1810 # because -1 >> x == -1 !
1814 $bin =~ s/.{$y}$//; # cut off at the right side
1815 $bin = '1' . $bin; # extend left side by one dummy '1'
1816 $bin =~ tr/10/01/; # flip bits back
1818 my $res = $self->new('0b'.$bin); # add prefix and convert back
1819 $res->binc(); # remember to increment
1820 $x->{value} = $res->{value}; # take over value
1821 return $x->round(@r); # we are done now, magic, isn't?
1823 # x < 0, n == 2, y == 1
1824 $x->bdec(); # n == 2, but $y == 1: this fixes it
1827 $x->{value} = $CALC->_rsft($x->{value},$y->{value},$n);
1833 #(BINT or num_str, BINT or num_str) return BINT
1837 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1838 # objectify is costly, so avoid it
1839 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1841 ($self,$x,$y,@r) = objectify(2,@_);
1844 return $x if $x->modify('band');
1846 $r[3] = $y; # no push!
1848 return $x->bnan() if ($x->{sign} !~ /^[+-]$/ || $y->{sign} !~ /^[+-]$/);
1850 my $sx = $x->{sign} eq '+' ? 1 : -1;
1851 my $sy = $y->{sign} eq '+' ? 1 : -1;
1853 if ($sx == 1 && $sy == 1)
1855 $x->{value} = $CALC->_and($x->{value},$y->{value});
1856 return $x->round(@r);
1859 if ($CAN{signed_and})
1861 $x->{value} = $CALC->_signed_and($x->{value},$y->{value},$sx,$sy);
1862 return $x->round(@r);
1866 __emu_band($self,$x,$y,$sx,$sy,@r);
1871 #(BINT or num_str, BINT or num_str) return BINT
1875 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1876 # objectify is costly, so avoid it
1877 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1879 ($self,$x,$y,@r) = objectify(2,@_);
1882 return $x if $x->modify('bior');
1883 $r[3] = $y; # no push!
1885 return $x->bnan() if ($x->{sign} !~ /^[+-]$/ || $y->{sign} !~ /^[+-]$/);
1887 my $sx = $x->{sign} eq '+' ? 1 : -1;
1888 my $sy = $y->{sign} eq '+' ? 1 : -1;
1890 # the sign of X follows the sign of X, e.g. sign of Y irrelevant for bior()
1892 # don't use lib for negative values
1893 if ($sx == 1 && $sy == 1)
1895 $x->{value} = $CALC->_or($x->{value},$y->{value});
1896 return $x->round(@r);
1899 # if lib can do negative values, let it handle this
1900 if ($CAN{signed_or})
1902 $x->{value} = $CALC->_signed_or($x->{value},$y->{value},$sx,$sy);
1903 return $x->round(@r);
1907 __emu_bior($self,$x,$y,$sx,$sy,@r);
1912 #(BINT or num_str, BINT or num_str) return BINT
1916 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1917 # objectify is costly, so avoid it
1918 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1920 ($self,$x,$y,@r) = objectify(2,@_);
1923 return $x if $x->modify('bxor');
1924 $r[3] = $y; # no push!
1926 return $x->bnan() if ($x->{sign} !~ /^[+-]$/ || $y->{sign} !~ /^[+-]$/);
1928 my $sx = $x->{sign} eq '+' ? 1 : -1;
1929 my $sy = $y->{sign} eq '+' ? 1 : -1;
1931 # don't use lib for negative values
1932 if ($sx == 1 && $sy == 1)
1934 $x->{value} = $CALC->_xor($x->{value},$y->{value});
1935 return $x->round(@r);
1938 # if lib can do negative values, let it handle this
1939 if ($CAN{signed_xor})
1941 $x->{value} = $CALC->_signed_xor($x->{value},$y->{value},$sx,$sy);
1942 return $x->round(@r);
1946 __emu_bxor($self,$x,$y,$sx,$sy,@r);
1951 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1953 my $e = $CALC->_len($x->{value});
1954 wantarray ? ($e,0) : $e;
1959 # return the nth decimal digit, negative values count backward, 0 is right
1960 my ($self,$x,$n) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
1962 $n = $n->numify() if ref($n);
1963 $CALC->_digit($x->{value},$n||0);
1968 # return the amount of trailing zeros in $x (as scalar)
1970 $x = $class->new($x) unless ref $x;
1972 return 0 if $x->{sign} !~ /^[+-]$/; # NaN, inf, -inf etc
1974 $CALC->_zeros($x->{value}); # must handle odd values, 0 etc
1979 # calculate square root of $x
1980 my ($self,$x,@r) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
1982 return $x if $x->modify('bsqrt');
1984 return $x->bnan() if $x->{sign} !~ /^\+/; # -x or -inf or NaN => NaN
1985 return $x if $x->{sign} eq '+inf'; # sqrt(+inf) == inf
1987 return $upgrade->bsqrt($x,@r) if defined $upgrade;
1989 $x->{value} = $CALC->_sqrt($x->{value});
1995 # calculate $y'th root of $x
1998 my ($self,$x,$y,@r) = (ref($_[0]),@_);
2000 $y = $self->new(2) unless defined $y;
2002 # objectify is costly, so avoid it
2003 if ((!ref($x)) || (ref($x) ne ref($y)))
2005 ($self,$x,$y,@r) = objectify(2,$self || $class,@_);
2008 return $x if $x->modify('broot');
2010 # NaN handling: $x ** 1/0, x or y NaN, or y inf/-inf or y == 0
2011 return $x->bnan() if $x->{sign} !~ /^\+/ || $y->is_zero() ||
2012 $y->{sign} !~ /^\+$/;
2014 return $x->round(@r)
2015 if $x->is_zero() || $x->is_one() || $x->is_inf() || $y->is_one();
2017 return $upgrade->new($x)->broot($upgrade->new($y),@r) if defined $upgrade;
2019 $x->{value} = $CALC->_root($x->{value},$y->{value});
2025 # return a copy of the exponent (here always 0, NaN or 1 for $m == 0)
2026 my ($self,$x) = ref($_[0]) ? (ref($_[0]),$_[0]) : objectify(1,@_);
2028 if ($x->{sign} !~ /^[+-]$/)
2030 my $s = $x->{sign}; $s =~ s/^[+-]//; # NaN, -inf,+inf => NaN or inf
2031 return $self->new($s);
2033 return $self->bone() if $x->is_zero();
2035 $self->new($x->_trailing_zeros());
2040 # return the mantissa (compatible to Math::BigFloat, e.g. reduced)
2041 my ($self,$x) = ref($_[0]) ? (ref($_[0]),$_[0]) : objectify(1,@_);
2043 if ($x->{sign} !~ /^[+-]$/)
2045 # for NaN, +inf, -inf: keep the sign
2046 return $self->new($x->{sign});
2048 my $m = $x->copy(); delete $m->{_p}; delete $m->{_a};
2049 # that's a bit inefficient:
2050 my $zeros = $m->_trailing_zeros();
2051 $m->brsft($zeros,10) if $zeros != 0;
2057 # return a copy of both the exponent and the mantissa
2058 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
2060 ($x->mantissa(),$x->exponent());
2063 ##############################################################################
2064 # rounding functions
2068 # precision: round to the $Nth digit left (+$n) or right (-$n) from the '.'
2069 # $n == 0 || $n == 1 => round to integer
2070 my $x = shift; my $self = ref($x) || $x; $x = $self->new($x) unless ref $x;
2072 my ($scale,$mode) = $x->_scale_p(@_);
2074 return $x if !defined $scale || $x->modify('bfround'); # no-op
2076 # no-op for BigInts if $n <= 0
2077 $x->bround( $x->length()-$scale, $mode) if $scale > 0;
2079 delete $x->{_a}; # delete to save memory
2080 $x->{_p} = $scale; # store new _p
2084 sub _scan_for_nonzero
2086 # internal, used by bround() to scan for non-zeros after a '5'
2087 my ($x,$pad,$xs,$len) = @_;
2089 return 0 if $len == 1; # "5" is trailed by invisible zeros
2090 my $follow = $pad - 1;
2091 return 0 if $follow > $len || $follow < 1;
2093 # use the string form to check whether only '0's follow or not
2094 substr ($xs,-$follow) =~ /[^0]/ ? 1 : 0;
2099 # Exists to make life easier for switch between MBF and MBI (should we
2100 # autoload fxxx() like MBF does for bxxx()?)
2101 my $x = shift; $x = $class->new($x) unless ref $x;
2107 # accuracy: +$n preserve $n digits from left,
2108 # -$n preserve $n digits from right (f.i. for 0.1234 style in MBF)
2110 # and overwrite the rest with 0's, return normalized number
2111 # do not return $x->bnorm(), but $x
2113 my $x = shift; $x = $class->new($x) unless ref $x;
2114 my ($scale,$mode) = $x->_scale_a(@_);
2115 return $x if !defined $scale || $x->modify('bround'); # no-op
2117 if ($x->is_zero() || $scale == 0)
2119 $x->{_a} = $scale if !defined $x->{_a} || $x->{_a} > $scale; # 3 > 2
2122 return $x if $x->{sign} !~ /^[+-]$/; # inf, NaN
2124 # we have fewer digits than we want to scale to
2125 my $len = $x->length();
2126 # convert $scale to a scalar in case it is an object (put's a limit on the
2127 # number length, but this would already limited by memory constraints), makes
2129 $scale = $scale->numify() if ref ($scale);
2131 # scale < 0, but > -len (not >=!)
2132 if (($scale < 0 && $scale < -$len-1) || ($scale >= $len))
2134 $x->{_a} = $scale if !defined $x->{_a} || $x->{_a} > $scale; # 3 > 2
2138 # count of 0's to pad, from left (+) or right (-): 9 - +6 => 3, or |-6| => 6
2139 my ($pad,$digit_round,$digit_after);
2140 $pad = $len - $scale;
2141 $pad = abs($scale-1) if $scale < 0;
2143 # do not use digit(), it is very costly for binary => decimal
2144 # getting the entire string is also costly, but we need to do it only once
2145 my $xs = $CALC->_str($x->{value});
2148 # pad: 123: 0 => -1, at 1 => -2, at 2 => -3, at 3 => -4
2149 # pad+1: 123: 0 => 0, at 1 => -1, at 2 => -2, at 3 => -3
2150 $digit_round = '0'; $digit_round = substr($xs,$pl,1) if $pad <= $len;
2151 $pl++; $pl ++ if $pad >= $len;
2152 $digit_after = '0'; $digit_after = substr($xs,$pl,1) if $pad > 0;
2154 # in case of 01234 we round down, for 6789 up, and only in case 5 we look
2155 # closer at the remaining digits of the original $x, remember decision
2156 my $round_up = 1; # default round up
2158 ($mode eq 'trunc') || # trunc by round down
2159 ($digit_after =~ /[01234]/) || # round down anyway,
2161 ($digit_after eq '5') && # not 5000...0000
2162 ($x->_scan_for_nonzero($pad,$xs,$len) == 0) &&
2164 ($mode eq 'even') && ($digit_round =~ /[24680]/) ||
2165 ($mode eq 'odd') && ($digit_round =~ /[13579]/) ||
2166 ($mode eq '+inf') && ($x->{sign} eq '-') ||
2167 ($mode eq '-inf') && ($x->{sign} eq '+') ||
2168 ($mode eq 'zero') # round down if zero, sign adjusted below
2170 my $put_back = 0; # not yet modified
2172 if (($pad > 0) && ($pad <= $len))
2174 substr($xs,-$pad,$pad) = '0' x $pad; # replace with '00...'
2175 $put_back = 1; # need to put back
2179 $x->bzero(); # round to '0'
2182 if ($round_up) # what gave test above?
2184 $put_back = 1; # need to put back
2185 $pad = $len, $xs = '0' x $pad if $scale < 0; # tlr: whack 0.51=>1.0
2187 # we modify directly the string variant instead of creating a number and
2188 # adding it, since that is faster (we already have the string)
2189 my $c = 0; $pad ++; # for $pad == $len case
2190 while ($pad <= $len)
2192 $c = substr($xs,-$pad,1) + 1; $c = '0' if $c eq '10';
2193 substr($xs,-$pad,1) = $c; $pad++;
2194 last if $c != 0; # no overflow => early out
2196 $xs = '1'.$xs if $c == 0;
2199 $x->{value} = $CALC->_new($xs) if $put_back == 1; # put back, if needed
2201 $x->{_a} = $scale if $scale >= 0;
2204 $x->{_a} = $len+$scale;
2205 $x->{_a} = 0 if $scale < -$len;
2212 # return integer less or equal then number; no-op since it's already integer
2213 my ($self,$x,@r) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
2220 # return integer greater or equal then number; no-op since it's already int
2221 my ($self,$x,@r) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
2228 # An object might be asked to return itself as bigint on certain overloaded
2229 # operations. This does exactly this, so that sub classes can simple inherit
2230 # it or override with their own integer conversion routine.
2236 # return as hex string, with prefixed 0x
2237 my $x = shift; $x = $class->new($x) if !ref($x);
2239 return $x->bstr() if $x->{sign} !~ /^[+-]$/; # inf, nan etc
2242 $s = $x->{sign} if $x->{sign} eq '-';
2243 $s . $CALC->_as_hex($x->{value});
2248 # return as binary string, with prefixed 0b
2249 my $x = shift; $x = $class->new($x) if !ref($x);
2251 return $x->bstr() if $x->{sign} !~ /^[+-]$/; # inf, nan etc
2253 my $s = ''; $s = $x->{sign} if $x->{sign} eq '-';
2254 return $s . $CALC->_as_bin($x->{value});
2259 # return as octal string, with prefixed 0
2260 my $x = shift; $x = $class->new($x) if !ref($x);
2262 return $x->bstr() if $x->{sign} !~ /^[+-]$/; # inf, nan etc
2264 my $s = ''; $s = $x->{sign} if $x->{sign} eq '-';
2265 return $s . $CALC->_as_oct($x->{value});
2268 ##############################################################################
2269 # private stuff (internal use only)
2273 # check for strings, if yes, return objects instead
2275 # the first argument is number of args objectify() should look at it will
2276 # return $count+1 elements, the first will be a classname. This is because
2277 # overloaded '""' calls bstr($object,undef,undef) and this would result in
2278 # useless objects being created and thrown away. So we cannot simple loop
2279 # over @_. If the given count is 0, all arguments will be used.
2281 # If the second arg is a ref, use it as class.
2282 # If not, try to use it as classname, unless undef, then use $class
2283 # (aka Math::BigInt). The latter shouldn't happen,though.
2286 # $x->badd(1); => ref x, scalar y
2287 # Class->badd(1,2); => classname x (scalar), scalar x, scalar y
2288 # Class->badd( Class->(1),2); => classname x (scalar), ref x, scalar y
2289 # Math::BigInt::badd(1,2); => scalar x, scalar y
2290 # In the last case we check number of arguments to turn it silently into
2291 # $class,1,2. (We can not take '1' as class ;o)
2292 # badd($class,1) is not supported (it should, eventually, try to add undef)
2293 # currently it tries 'Math::BigInt' + 1, which will not work.
2295 # some shortcut for the common cases
2297 return (ref($_[1]),$_[1]) if (@_ == 2) && ($_[0]||0 == 1) && ref($_[1]);
2299 my $count = abs(shift || 0);
2301 my (@a,$k,$d); # resulting array, temp, and downgrade
2304 # okay, got object as first
2309 # nope, got 1,2 (Class->xxx(1) => Class,1 and not supported)
2311 $a[0] = shift if $_[0] =~ /^[A-Z].*::/; # classname as first?
2315 # disable downgrading, because Math::BigFLoat->foo('1.0','2.0') needs floats
2316 if (defined ${"$a[0]::downgrade"})
2318 $d = ${"$a[0]::downgrade"};
2319 ${"$a[0]::downgrade"} = undef;
2322 my $up = ${"$a[0]::upgrade"};
2323 #print "Now in objectify, my class is today $a[0], count = $count\n";
2331 $k = $a[0]->new($k);
2333 elsif (!defined $up && ref($k) ne $a[0])
2335 # foreign object, try to convert to integer
2336 $k->can('as_number') ? $k = $k->as_number() : $k = $a[0]->new($k);
2349 $k = $a[0]->new($k);
2351 elsif (!defined $up && ref($k) ne $a[0])
2353 # foreign object, try to convert to integer
2354 $k->can('as_number') ? $k = $k->as_number() : $k = $a[0]->new($k);
2358 push @a,@_; # return other params, too
2362 require Carp; Carp::croak ("$class objectify needs list context");
2364 ${"$a[0]::downgrade"} = $d;
2368 sub _register_callback
2370 my ($class,$callback) = @_;
2372 if (ref($callback) ne 'CODE')
2375 Carp::croak ("$callback is not a coderef");
2377 $CALLBACKS{$class} = $callback;
2384 $IMPORT++; # remember we did import()
2385 my @a; my $l = scalar @_;
2386 my $warn_or_die = 0; # 0 - no warn, 1 - warn, 2 - die
2387 for ( my $i = 0; $i < $l ; $i++ )
2389 if ($_[$i] eq ':constant')
2391 # this causes overlord er load to step in
2393 integer => sub { $self->new(shift) },
2394 binary => sub { $self->new(shift) };
2396 elsif ($_[$i] eq 'upgrade')
2398 # this causes upgrading
2399 $upgrade = $_[$i+1]; # or undef to disable
2402 elsif ($_[$i] =~ /^(lib|try|only)\z/)
2404 # this causes a different low lib to take care...
2405 $CALC = $_[$i+1] || '';
2406 # lib => 1 (warn on fallback), try => 0 (no warn), only => 2 (die on fallback)
2407 $warn_or_die = 1 if $_[$i] eq 'lib';
2408 $warn_or_die = 2 if $_[$i] eq 'only';
2416 # any non :constant stuff is handled by our parent, Exporter
2421 $self->SUPER::import(@a); # need it for subclasses
2422 $self->export_to_level(1,$self,@a); # need it for MBF
2425 # try to load core math lib
2426 my @c = split /\s*,\s*/,$CALC;
2429 $_ =~ tr/a-zA-Z0-9://cd; # limit to sane characters
2431 push @c, \'FastCalc', \'Calc' # if all fail, try these
2432 if $warn_or_die < 2; # but not for "only"
2433 $CALC = ''; # signal error
2436 # fallback libraries are "marked" as \'string', extract string if nec.
2437 my $lib = $l; $lib = $$l if ref($l);
2439 next if ($lib || '') eq '';
2440 $lib = 'Math::BigInt::'.$lib if $lib !~ /^Math::BigInt/i;
2444 # Perl < 5.6.0 dies with "out of memory!" when eval("") and ':constant' is
2445 # used in the same script, or eval("") inside import().
2446 my @parts = split /::/, $lib; # Math::BigInt => Math BigInt
2447 my $file = pop @parts; $file .= '.pm'; # BigInt => BigInt.pm
2449 $file = File::Spec->catfile (@parts, $file);
2450 eval { require "$file"; $lib->import( @c ); }
2454 eval "use $lib qw/@c/;";
2459 # loaded it ok, see if the api_version() is high enough
2460 if ($lib->can('api_version') && $lib->api_version() >= 1.0)
2463 # api_version matches, check if it really provides anything we need
2467 add mul div sub dec inc
2468 acmp len digit is_one is_zero is_even is_odd
2470 zeros new copy check
2471 from_hex from_oct from_bin as_hex as_bin as_oct
2472 rsft lsft xor and or
2473 mod sqrt root fac pow modinv modpow log_int gcd
2476 if (!$lib->can("_$method"))
2478 if (($WARN{$lib}||0) < 2)
2481 Carp::carp ("$lib is missing method '_$method'");
2482 $WARN{$lib} = 1; # still warn about the lib
2491 if ($warn_or_die > 0 && ref($l))
2494 my $msg = "Math::BigInt: couldn't load specified math lib(s), fallback to $lib";
2495 Carp::carp ($msg) if $warn_or_die == 1;
2496 Carp::croak ($msg) if $warn_or_die == 2;
2498 last; # found a usable one, break
2502 if (($WARN{$lib}||0) < 2)
2504 my $ver = eval "\$$lib\::VERSION" || 'unknown';
2506 Carp::carp ("Cannot load outdated $lib v$ver, please upgrade");
2507 $WARN{$lib} = 2; # never warn again
2515 if ($warn_or_die == 2)
2517 Carp::croak ("Couldn't load specified math lib(s) and fallback disallowed");
2521 Carp::croak ("Couldn't load any math lib(s), not even fallback to Calc.pm");
2526 foreach my $class (keys %CALLBACKS)
2528 &{$CALLBACKS{$class}}($CALC);
2531 # Fill $CAN with the results of $CALC->can(...) for emulating lower math lib
2535 for my $method (qw/ signed_and signed_or signed_xor /)
2537 $CAN{$method} = $CALC->can("_$method") ? 1 : 0;
2545 # create a bigint from a hexadecimal string
2546 my ($self, $hs) = @_;
2548 my $rc = $self->__from_hex($hs);
2550 return $self->bnan() unless defined $rc;
2557 # create a bigint from a hexadecimal string
2558 my ($self, $bs) = @_;
2560 my $rc = $self->__from_bin($bs);
2562 return $self->bnan() unless defined $rc;
2569 # create a bigint from a hexadecimal string
2570 my ($self, $os) = @_;
2572 my $x = $self->bzero();
2575 $os =~ s/([0-9a-fA-F])_([0-9a-fA-F])/$1$2/g;
2576 $os =~ s/([0-9a-fA-F])_([0-9a-fA-F])/$1$2/g;
2578 return $x->bnan() if $os !~ /^[\-\+]?0[0-9]+$/;
2580 my $sign = '+'; $sign = '-' if $os =~ /^-/;
2582 $os =~ s/^[+-]//; # strip sign
2583 $x->{value} = $CALC->_from_oct($os);
2584 $x->{sign} = $sign unless $CALC->_is_zero($x->{value}); # no '-0'
2591 # convert a (ref to) big hex string to BigInt, return undef for error
2594 my $x = Math::BigInt->bzero();
2597 $hs =~ s/([0-9a-fA-F])_([0-9a-fA-F])/$1$2/g;
2598 $hs =~ s/([0-9a-fA-F])_([0-9a-fA-F])/$1$2/g;
2600 return $x->bnan() if $hs !~ /^[\-\+]?0x[0-9A-Fa-f]+$/;
2602 my $sign = '+'; $sign = '-' if $hs =~ /^-/;
2604 $hs =~ s/^[+-]//; # strip sign
2605 $x->{value} = $CALC->_from_hex($hs);
2606 $x->{sign} = $sign unless $CALC->_is_zero($x->{value}); # no '-0'
2613 # convert a (ref to) big binary string to BigInt, return undef for error
2616 my $x = Math::BigInt->bzero();
2619 $bs =~ s/([01])_([01])/$1$2/g;
2620 $bs =~ s/([01])_([01])/$1$2/g;
2621 return $x->bnan() if $bs !~ /^[+-]?0b[01]+$/;
2623 my $sign = '+'; $sign = '-' if $bs =~ /^\-/;
2624 $bs =~ s/^[+-]//; # strip sign
2626 $x->{value} = $CALC->_from_bin($bs);
2627 $x->{sign} = $sign unless $CALC->_is_zero($x->{value}); # no '-0'
2633 # input: num_str; output: undef for invalid or
2634 # (\$mantissa_sign,\$mantissa_value,\$mantissa_fraction,\$exp_sign,\$exp_value)
2635 # Internal, take apart a string and return the pieces.
2636 # Strip leading/trailing whitespace, leading zeros, underscore and reject
2640 # strip white space at front, also extranous leading zeros
2641 $x =~ s/^\s*([-]?)0*([0-9])/$1$2/g; # will not strip ' .2'
2642 $x =~ s/^\s+//; # but this will
2643 $x =~ s/\s+$//g; # strip white space at end
2645 # shortcut, if nothing to split, return early
2646 if ($x =~ /^[+-]?[0-9]+\z/)
2648 $x =~ s/^([+-])0*([0-9])/$2/; my $sign = $1 || '+';
2649 return (\$sign, \$x, \'', \'', \0);
2652 # invalid starting char?
2653 return if $x !~ /^[+-]?(\.?[0-9]|0b[0-1]|0x[0-9a-fA-F])/;
2655 return __from_hex($x) if $x =~ /^[\-\+]?0x/; # hex string
2656 return __from_bin($x) if $x =~ /^[\-\+]?0b/; # binary string
2658 # strip underscores between digits
2659 $x =~ s/([0-9])_([0-9])/$1$2/g;
2660 $x =~ s/([0-9])_([0-9])/$1$2/g; # do twice for 1_2_3
2662 # some possible inputs:
2663 # 2.1234 # 0.12 # 1 # 1E1 # 2.134E1 # 434E-10 # 1.02009E-2
2664 # .2 # 1_2_3.4_5_6 # 1.4E1_2_3 # 1e3 # +.2 # 0e999
2666 my ($m,$e,$last) = split /[Ee]/,$x;
2667 return if defined $last; # last defined => 1e2E3 or others
2668 $e = '0' if !defined $e || $e eq "";
2670 # sign,value for exponent,mantint,mantfrac
2671 my ($es,$ev,$mis,$miv,$mfv);
2673 if ($e =~ /^([+-]?)0*([0-9]+)$/) # strip leading zeros
2677 return if $m eq '.' || $m eq '';
2678 my ($mi,$mf,$lastf) = split /\./,$m;
2679 return if defined $lastf; # lastf defined => 1.2.3 or others
2680 $mi = '0' if !defined $mi;
2681 $mi .= '0' if $mi =~ /^[\-\+]?$/;
2682 $mf = '0' if !defined $mf || $mf eq '';
2683 if ($mi =~ /^([+-]?)0*([0-9]+)$/) # strip leading zeros
2685 $mis = $1||'+'; $miv = $2;
2686 return unless ($mf =~ /^([0-9]*?)0*$/); # strip trailing zeros
2688 # handle the 0e999 case here
2689 $ev = 0 if $miv eq '0' && $mfv eq '';
2690 return (\$mis,\$miv,\$mfv,\$es,\$ev);
2693 return; # NaN, not a number
2696 ##############################################################################
2697 # internal calculation routines (others are in Math::BigInt::Calc etc)
2701 # (BINT or num_str, BINT or num_str) return BINT
2702 # does modify first argument
2706 return $x->bnan() if ($x->{sign} eq $nan) || ($ty->{sign} eq $nan);
2707 my $method = ref($x) . '::bgcd';
2709 $x * $ty / &$method($x,$ty);
2712 ###############################################################################
2713 # this method returns 0 if the object can be modified, or 1 if not.
2714 # We use a fast constant sub() here, to avoid costly calls. Subclasses
2715 # may override it with special code (f.i. Math::BigInt::Constant does so)
2717 sub modify () { 0; }
2726 Math::BigInt - Arbitrary size integer/float math package
2732 # or make it faster: install (optional) Math::BigInt::GMP
2733 # and always use (it will fall back to pure Perl if the
2734 # GMP library is not installed):
2736 # will warn if Math::BigInt::GMP cannot be found
2737 use Math::BigInt lib => 'GMP';
2739 # to supress the warning use this:
2740 # use Math::BigInt try => 'GMP';
2742 my $str = '1234567890';
2743 my @values = (64,74,18);
2744 my $n = 1; my $sign = '-';
2747 $x = Math::BigInt->new($str); # defaults to 0
2748 $y = $x->copy(); # make a true copy
2749 $nan = Math::BigInt->bnan(); # create a NotANumber
2750 $zero = Math::BigInt->bzero(); # create a +0
2751 $inf = Math::BigInt->binf(); # create a +inf
2752 $inf = Math::BigInt->binf('-'); # create a -inf
2753 $one = Math::BigInt->bone(); # create a +1
2754 $one = Math::BigInt->bone('-'); # create a -1
2756 $h = Math::BigInt->new('0x123'); # from hexadecimal
2757 $b = Math::BigInt->new('0b101'); # from binary
2758 $o = Math::BigInt->from_oct('0101'); # from octal
2760 # Testing (don't modify their arguments)
2761 # (return true if the condition is met, otherwise false)
2763 $x->is_zero(); # if $x is +0
2764 $x->is_nan(); # if $x is NaN
2765 $x->is_one(); # if $x is +1
2766 $x->is_one('-'); # if $x is -1
2767 $x->is_odd(); # if $x is odd
2768 $x->is_even(); # if $x is even
2769 $x->is_pos(); # if $x >= 0
2770 $x->is_neg(); # if $x < 0
2771 $x->is_inf($sign); # if $x is +inf, or -inf (sign is default '+')
2772 $x->is_int(); # if $x is an integer (not a float)
2774 # comparing and digit/sign extraction
2775 $x->bcmp($y); # compare numbers (undef,<0,=0,>0)
2776 $x->bacmp($y); # compare absolutely (undef,<0,=0,>0)
2777 $x->sign(); # return the sign, either +,- or NaN
2778 $x->digit($n); # return the nth digit, counting from right
2779 $x->digit(-$n); # return the nth digit, counting from left
2781 # The following all modify their first argument. If you want to preserve
2782 # $x, use $z = $x->copy()->bXXX($y); See under L<CAVEATS> for why this is
2783 # necessary when mixing $a = $b assignments with non-overloaded math.
2785 $x->bzero(); # set $x to 0
2786 $x->bnan(); # set $x to NaN
2787 $x->bone(); # set $x to +1
2788 $x->bone('-'); # set $x to -1
2789 $x->binf(); # set $x to inf
2790 $x->binf('-'); # set $x to -inf
2792 $x->bneg(); # negation
2793 $x->babs(); # absolute value
2794 $x->bnorm(); # normalize (no-op in BigInt)
2795 $x->bnot(); # two's complement (bit wise not)
2796 $x->binc(); # increment $x by 1
2797 $x->bdec(); # decrement $x by 1
2799 $x->badd($y); # addition (add $y to $x)
2800 $x->bsub($y); # subtraction (subtract $y from $x)
2801 $x->bmul($y); # multiplication (multiply $x by $y)
2802 $x->bdiv($y); # divide, set $x to quotient
2803 # return (quo,rem) or quo if scalar
2805 $x->bmod($y); # modulus (x % y)
2806 $x->bmodpow($exp,$mod); # modular exponentation (($num**$exp) % $mod))
2807 $x->bmodinv($mod); # the inverse of $x in the given modulus $mod
2809 $x->bpow($y); # power of arguments (x ** y)
2810 $x->blsft($y); # left shift in base 10
2811 $x->brsft($y); # right shift in base 10
2812 # returns (quo,rem) or quo if in scalar context
2813 $x->blsft($y,$n); # left shift by $y places in base $n
2814 $x->brsft($y,$n); # right shift by $y places in base $n
2815 # returns (quo,rem) or quo if in scalar context
2817 $x->band($y); # bitwise and
2818 $x->bior($y); # bitwise inclusive or
2819 $x->bxor($y); # bitwise exclusive or
2820 $x->bnot(); # bitwise not (two's complement)
2822 $x->bsqrt(); # calculate square-root
2823 $x->broot($y); # $y'th root of $x (e.g. $y == 3 => cubic root)
2824 $x->bfac(); # factorial of $x (1*2*3*4*..$x)
2826 $x->round($A,$P,$mode); # round to accuracy or precision using mode $mode
2827 $x->bround($n); # accuracy: preserve $n digits
2828 $x->bfround($n); # round to $nth digit, no-op for BigInts
2830 # The following do not modify their arguments in BigInt (are no-ops),
2831 # but do so in BigFloat:
2833 $x->bfloor(); # return integer less or equal than $x
2834 $x->bceil(); # return integer greater or equal than $x
2836 # The following do not modify their arguments:
2838 # greatest common divisor (no OO style)
2839 my $gcd = Math::BigInt::bgcd(@values);
2840 # lowest common multiplicator (no OO style)
2841 my $lcm = Math::BigInt::blcm(@values);
2843 $x->length(); # return number of digits in number
2844 ($xl,$f) = $x->length(); # length of number and length of fraction part,
2845 # latter is always 0 digits long for BigInts
2847 $x->exponent(); # return exponent as BigInt
2848 $x->mantissa(); # return (signed) mantissa as BigInt
2849 $x->parts(); # return (mantissa,exponent) as BigInt
2850 $x->copy(); # make a true copy of $x (unlike $y = $x;)
2851 $x->as_int(); # return as BigInt (in BigInt: same as copy())
2852 $x->numify(); # return as scalar (might overflow!)
2854 # conversation to string (do not modify their argument)
2855 $x->bstr(); # normalized string (e.g. '3')
2856 $x->bsstr(); # norm. string in scientific notation (e.g. '3E0')
2857 $x->as_hex(); # as signed hexadecimal string with prefixed 0x
2858 $x->as_bin(); # as signed binary string with prefixed 0b
2859 $x->as_oct(); # as signed octal string with prefixed 0
2862 # precision and accuracy (see section about rounding for more)
2863 $x->precision(); # return P of $x (or global, if P of $x undef)
2864 $x->precision($n); # set P of $x to $n
2865 $x->accuracy(); # return A of $x (or global, if A of $x undef)
2866 $x->accuracy($n); # set A $x to $n
2869 Math::BigInt->precision(); # get/set global P for all BigInt objects
2870 Math::BigInt->accuracy(); # get/set global A for all BigInt objects
2871 Math::BigInt->round_mode(); # get/set global round mode, one of
2872 # 'even', 'odd', '+inf', '-inf', 'zero', 'trunc' or 'common'
2873 Math::BigInt->config(); # return hash containing configuration
2877 All operators (including basic math operations) are overloaded if you
2878 declare your big integers as
2880 $i = new Math::BigInt '123_456_789_123_456_789';
2882 Operations with overloaded operators preserve the arguments which is
2883 exactly what you expect.
2889 Input values to these routines may be any string, that looks like a number
2890 and results in an integer, including hexadecimal and binary numbers.
2892 Scalars holding numbers may also be passed, but note that non-integer numbers
2893 may already have lost precision due to the conversation to float. Quote
2894 your input if you want BigInt to see all the digits:
2896 $x = Math::BigInt->new(12345678890123456789); # bad
2897 $x = Math::BigInt->new('12345678901234567890'); # good
2899 You can include one underscore between any two digits.
2901 This means integer values like 1.01E2 or even 1000E-2 are also accepted.
2902 Non-integer values result in NaN.
2904 Hexadecimal (prefixed with "0x") and binary numbers (prefixed with "0b")
2905 are accepted, too. Please note that octal numbers are not recognized
2906 by new(), so the following will print "123":
2908 perl -MMath::BigInt -le 'print Math::BigInt->new("0123")'
2910 To convert an octal number, use from_oct();
2912 perl -MMath::BigInt -le 'print Math::BigInt->from_oct("0123")'
2914 Currently, Math::BigInt::new() defaults to 0, while Math::BigInt::new('')
2915 results in 'NaN'. This might change in the future, so use always the following
2916 explicit forms to get a zero or NaN:
2918 $zero = Math::BigInt->bzero();
2919 $nan = Math::BigInt->bnan();
2921 C<bnorm()> on a BigInt object is now effectively a no-op, since the numbers
2922 are always stored in normalized form. If passed a string, creates a BigInt
2923 object from the input.
2927 Output values are BigInt objects (normalized), except for the methods which
2928 return a string (see L<SYNOPSIS>).
2930 Some routines (C<is_odd()>, C<is_even()>, C<is_zero()>, C<is_one()>,
2931 C<is_nan()>, etc.) return true or false, while others (C<bcmp()>, C<bacmp()>)
2932 return either undef (if NaN is involved), <0, 0 or >0 and are suited for sort.
2938 Each of the methods below (except config(), accuracy() and precision())
2939 accepts three additional parameters. These arguments C<$A>, C<$P> and C<$R>
2940 are C<accuracy>, C<precision> and C<round_mode>. Please see the section about
2941 L<ACCURACY and PRECISION> for more information.
2947 print Dumper ( Math::BigInt->config() );
2948 print Math::BigInt->config()->{lib},"\n";
2950 Returns a hash containing the configuration, e.g. the version number, lib
2951 loaded etc. The following hash keys are currently filled in with the
2952 appropriate information.
2956 ============================================================
2957 lib Name of the low-level math library
2959 lib_version Version of low-level math library (see 'lib')
2961 class The class name of config() you just called
2963 upgrade To which class math operations might be upgraded
2965 downgrade To which class math operations might be downgraded
2967 precision Global precision
2969 accuracy Global accuracy
2971 round_mode Global round mode
2973 version version number of the class you used
2975 div_scale Fallback accuracy for div
2977 trap_nan If true, traps creation of NaN via croak()
2979 trap_inf If true, traps creation of +inf/-inf via croak()
2982 The following values can be set by passing C<config()> a reference to a hash:
2985 upgrade downgrade precision accuracy round_mode div_scale
2989 $new_cfg = Math::BigInt->config( { trap_inf => 1, precision => 5 } );
2993 $x->accuracy(5); # local for $x
2994 CLASS->accuracy(5); # global for all members of CLASS
2995 # Note: This also applies to new()!
2997 $A = $x->accuracy(); # read out accuracy that affects $x
2998 $A = CLASS->accuracy(); # read out global accuracy
3000 Set or get the global or local accuracy, aka how many significant digits the
3001 results have. If you set a global accuracy, then this also applies to new()!
3003 Warning! The accuracy I<sticks>, e.g. once you created a number under the
3004 influence of C<< CLASS->accuracy($A) >>, all results from math operations with
3005 that number will also be rounded.
3007 In most cases, you should probably round the results explicitly using one of
3008 L<round()>, L<bround()> or L<bfround()> or by passing the desired accuracy
3009 to the math operation as additional parameter:
3011 my $x = Math::BigInt->new(30000);
3012 my $y = Math::BigInt->new(7);
3013 print scalar $x->copy()->bdiv($y, 2); # print 4300
3014 print scalar $x->copy()->bdiv($y)->bround(2); # print 4300
3016 Please see the section about L<ACCURACY AND PRECISION> for further details.
3018 Value must be greater than zero. Pass an undef value to disable it:
3020 $x->accuracy(undef);
3021 Math::BigInt->accuracy(undef);
3023 Returns the current accuracy. For C<$x->accuracy()> it will return either the
3024 local accuracy, or if not defined, the global. This means the return value
3025 represents the accuracy that will be in effect for $x:
3027 $y = Math::BigInt->new(1234567); # unrounded
3028 print Math::BigInt->accuracy(4),"\n"; # set 4, print 4
3029 $x = Math::BigInt->new(123456); # $x will be automatically rounded!
3030 print "$x $y\n"; # '123500 1234567'
3031 print $x->accuracy(),"\n"; # will be 4
3032 print $y->accuracy(),"\n"; # also 4, since global is 4
3033 print Math::BigInt->accuracy(5),"\n"; # set to 5, print 5
3034 print $x->accuracy(),"\n"; # still 4
3035 print $y->accuracy(),"\n"; # 5, since global is 5
3037 Note: Works also for subclasses like Math::BigFloat. Each class has it's own
3038 globals separated from Math::BigInt, but it is possible to subclass
3039 Math::BigInt and make the globals of the subclass aliases to the ones from
3044 $x->precision(-2); # local for $x, round at the second digit right of the dot
3045 $x->precision(2); # ditto, round at the second digit left of the dot
3047 CLASS->precision(5); # Global for all members of CLASS
3048 # This also applies to new()!
3049 CLASS->precision(-5); # ditto
3051 $P = CLASS->precision(); # read out global precision
3052 $P = $x->precision(); # read out precision that affects $x
3054 Note: You probably want to use L<accuracy()> instead. With L<accuracy> you
3055 set the number of digits each result should have, with L<precision> you
3056 set the place where to round!
3058 C<precision()> sets or gets the global or local precision, aka at which digit
3059 before or after the dot to round all results. A set global precision also
3060 applies to all newly created numbers!
3062 In Math::BigInt, passing a negative number precision has no effect since no
3063 numbers have digits after the dot. In L<Math::BigFloat>, it will round all
3064 results to P digits after the dot.
3066 Please see the section about L<ACCURACY AND PRECISION> for further details.
3068 Pass an undef value to disable it:
3070 $x->precision(undef);
3071 Math::BigInt->precision(undef);
3073 Returns the current precision. For C<$x->precision()> it will return either the
3074 local precision of $x, or if not defined, the global. This means the return
3075 value represents the prevision that will be in effect for $x:
3077 $y = Math::BigInt->new(1234567); # unrounded
3078 print Math::BigInt->precision(4),"\n"; # set 4, print 4
3079 $x = Math::BigInt->new(123456); # will be automatically rounded
3080 print $x; # print "120000"!
3082 Note: Works also for subclasses like L<Math::BigFloat>. Each class has its
3083 own globals separated from Math::BigInt, but it is possible to subclass
3084 Math::BigInt and make the globals of the subclass aliases to the ones from
3091 Shifts $x right by $y in base $n. Default is base 2, used are usually 10 and
3092 2, but others work, too.
3094 Right shifting usually amounts to dividing $x by $n ** $y and truncating the
3098 $x = Math::BigInt->new(10);
3099 $x->brsft(1); # same as $x >> 1: 5
3100 $x = Math::BigInt->new(1234);
3101 $x->brsft(2,10); # result 12
3103 There is one exception, and that is base 2 with negative $x:
3106 $x = Math::BigInt->new(-5);
3109 This will print -3, not -2 (as it would if you divide -5 by 2 and truncate the
3114 $x = Math::BigInt->new($str,$A,$P,$R);
3116 Creates a new BigInt object from a scalar or another BigInt object. The
3117 input is accepted as decimal, hex (with leading '0x') or binary (with leading
3120 See L<Input> for more info on accepted input formats.
3124 $x = Math::BigIn->from_oct("0775"); # input is octal
3128 $x = Math::BigIn->from_hex("0xcafe"); # input is hexadecimal
3132 $x = Math::BigIn->from_oct("0x10011"); # input is binary
3136 $x = Math::BigInt->bnan();
3138 Creates a new BigInt object representing NaN (Not A Number).
3139 If used on an object, it will set it to NaN:
3145 $x = Math::BigInt->bzero();
3147 Creates a new BigInt object representing zero.
3148 If used on an object, it will set it to zero:
3154 $x = Math::BigInt->binf($sign);
3156 Creates a new BigInt object representing infinity. The optional argument is
3157 either '-' or '+', indicating whether you want infinity or minus infinity.
3158 If used on an object, it will set it to infinity:
3165 $x = Math::BigInt->binf($sign);
3167 Creates a new BigInt object representing one. The optional argument is
3168 either '-' or '+', indicating whether you want one or minus one.
3169 If used on an object, it will set it to one:
3174 =head2 is_one()/is_zero()/is_nan()/is_inf()
3177 $x->is_zero(); # true if arg is +0
3178 $x->is_nan(); # true if arg is NaN
3179 $x->is_one(); # true if arg is +1
3180 $x->is_one('-'); # true if arg is -1
3181 $x->is_inf(); # true if +inf
3182 $x->is_inf('-'); # true if -inf (sign is default '+')
3184 These methods all test the BigInt for being one specific value and return
3185 true or false depending on the input. These are faster than doing something
3190 =head2 is_pos()/is_neg()/is_positive()/is_negative()
3192 $x->is_pos(); # true if > 0
3193 $x->is_neg(); # true if < 0
3195 The methods return true if the argument is positive or negative, respectively.
3196 C<NaN> is neither positive nor negative, while C<+inf> counts as positive, and
3197 C<-inf> is negative. A C<zero> is neither positive nor negative.
3199 These methods are only testing the sign, and not the value.
3201 C<is_positive()> and C<is_negative()> are aliases to C<is_pos()> and
3202 C<is_neg()>, respectively. C<is_positive()> and C<is_negative()> were
3203 introduced in v1.36, while C<is_pos()> and C<is_neg()> were only introduced
3206 =head2 is_odd()/is_even()/is_int()
3208 $x->is_odd(); # true if odd, false for even
3209 $x->is_even(); # true if even, false for odd
3210 $x->is_int(); # true if $x is an integer
3212 The return true when the argument satisfies the condition. C<NaN>, C<+inf>,
3213 C<-inf> are not integers and are neither odd nor even.
3215 In BigInt, all numbers except C<NaN>, C<+inf> and C<-inf> are integers.
3221 Compares $x with $y and takes the sign into account.
3222 Returns -1, 0, 1 or undef.
3228 Compares $x with $y while ignoring their. Returns -1, 0, 1 or undef.
3234 Return the sign, of $x, meaning either C<+>, C<->, C<-inf>, C<+inf> or NaN.
3236 If you want $x to have a certain sign, use one of the following methods:
3239 $x->babs()->bneg(); # '-'
3241 $x->binf(); # '+inf'
3242 $x->binf('-'); # '-inf'
3246 $x->digit($n); # return the nth digit, counting from right
3248 If C<$n> is negative, returns the digit counting from left.
3254 Negate the number, e.g. change the sign between '+' and '-', or between '+inf'
3255 and '-inf', respectively. Does nothing for NaN or zero.
3261 Set the number to it's absolute value, e.g. change the sign from '-' to '+'
3262 and from '-inf' to '+inf', respectively. Does nothing for NaN or positive
3267 $x->bnorm(); # normalize (no-op)
3273 Two's complement (bit wise not). This is equivalent to
3281 $x->binc(); # increment x by 1
3285 $x->bdec(); # decrement x by 1
3289 $x->badd($y); # addition (add $y to $x)
3293 $x->bsub($y); # subtraction (subtract $y from $x)
3297 $x->bmul($y); # multiplication (multiply $x by $y)
3301 $x->bdiv($y); # divide, set $x to quotient
3302 # return (quo,rem) or quo if scalar
3306 $x->bmod($y); # modulus (x % y)
3310 num->bmodinv($mod); # modular inverse
3312 Returns the inverse of C<$num> in the given modulus C<$mod>. 'C<NaN>' is
3313 returned unless C<$num> is relatively prime to C<$mod>, i.e. unless
3314 C<bgcd($num, $mod)==1>.
3318 $num->bmodpow($exp,$mod); # modular exponentation
3319 # ($num**$exp % $mod)
3321 Returns the value of C<$num> taken to the power C<$exp> in the modulus
3322 C<$mod> using binary exponentation. C<bmodpow> is far superior to
3327 because it is much faster - it reduces internal variables into
3328 the modulus whenever possible, so it operates on smaller numbers.
3330 C<bmodpow> also supports negative exponents.
3332 bmodpow($num, -1, $mod)
3334 is exactly equivalent to
3340 $x->bpow($y); # power of arguments (x ** y)
3344 $x->blsft($y); # left shift
3345 $x->blsft($y,$n); # left shift, in base $n (like 10)
3349 $x->brsft($y); # right shift
3350 $x->brsft($y,$n); # right shift, in base $n (like 10)
3354 $x->band($y); # bitwise and
3358 $x->bior($y); # bitwise inclusive or
3362 $x->bxor($y); # bitwise exclusive or
3366 $x->bnot(); # bitwise not (two's complement)
3370 $x->bsqrt(); # calculate square-root
3374 $x->bfac(); # factorial of $x (1*2*3*4*..$x)
3378 $x->round($A,$P,$round_mode);
3380 Round $x to accuracy C<$A> or precision C<$P> using the round mode
3385 $x->bround($N); # accuracy: preserve $N digits
3389 $x->bfround($N); # round to $Nth digit, no-op for BigInts
3395 Set $x to the integer less or equal than $x. This is a no-op in BigInt, but
3396 does change $x in BigFloat.
3402 Set $x to the integer greater or equal than $x. This is a no-op in BigInt, but
3403 does change $x in BigFloat.
3407 bgcd(@values); # greatest common divisor (no OO style)
3411 blcm(@values); # lowest common multiplicator (no OO style)
3416 ($xl,$fl) = $x->length();
3418 Returns the number of digits in the decimal representation of the number.
3419 In list context, returns the length of the integer and fraction part. For
3420 BigInt's, the length of the fraction part will always be 0.
3426 Return the exponent of $x as BigInt.
3432 Return the signed mantissa of $x as BigInt.
3436 $x->parts(); # return (mantissa,exponent) as BigInt
3440 $x->copy(); # make a true copy of $x (unlike $y = $x;)
3442 =head2 as_int()/as_number()
3446 Returns $x as a BigInt (truncated towards zero). In BigInt this is the same as
3449 C<as_number()> is an alias to this method. C<as_number> was introduced in
3450 v1.22, while C<as_int()> was only introduced in v1.68.
3456 Returns a normalized string representation of C<$x>.
3460 $x->bsstr(); # normalized string in scientific notation
3464 $x->as_hex(); # as signed hexadecimal string with prefixed 0x
3468 $x->as_bin(); # as signed binary string with prefixed 0b
3472 $x->as_oct(); # as signed octal string with prefixed 0
3478 This returns a normal Perl scalar from $x. It is used automatically
3479 whenever a scalar is needed, for instance in array index operations.
3481 This loses precision, to avoid this use L<as_int()> instead.
3485 $x->modify('bpowd');
3487 This method returns 0 if the object can be modified with the given
3488 peration, or 1 if not.
3490 This is used for instance by L<Math::BigInt::Constant>.
3492 =head2 upgrade()/downgrade()
3494 Set/get the class for downgrade/upgrade operations. Thuis is used
3495 for instance by L<bignum>. The defaults are '', thus the following
3496 operation will create a BigInt, not a BigFloat:
3498 my $i = Math::BigInt->new(123);
3499 my $f = Math::BigFloat->new('123.1');
3501 print $i + $f,"\n"; # print 246
3505 Set/get the number of digits for the default precision in divide
3510 Set/get the current round mode.
3512 =head1 ACCURACY and PRECISION
3514 Since version v1.33, Math::BigInt and Math::BigFloat have full support for
3515 accuracy and precision based rounding, both automatically after every
3516 operation, as well as manually.
3518 This section describes the accuracy/precision handling in Math::Big* as it
3519 used to be and as it is now, complete with an explanation of all terms and
3522 Not yet implemented things (but with correct description) are marked with '!',
3523 things that need to be answered are marked with '?'.
3525 In the next paragraph follows a short description of terms used here (because
3526 these may differ from terms used by others people or documentation).
3528 During the rest of this document, the shortcuts A (for accuracy), P (for
3529 precision), F (fallback) and R (rounding mode) will be used.
3533 A fixed number of digits before (positive) or after (negative)
3534 the decimal point. For example, 123.45 has a precision of -2. 0 means an
3535 integer like 123 (or 120). A precision of 2 means two digits to the left
3536 of the decimal point are zero, so 123 with P = 1 becomes 120. Note that
3537 numbers with zeros before the decimal point may have different precisions,
3538 because 1200 can have p = 0, 1 or 2 (depending on what the inital value
3539 was). It could also have p < 0, when the digits after the decimal point
3542 The string output (of floating point numbers) will be padded with zeros:
3544 Initial value P A Result String
3545 ------------------------------------------------------------
3546 1234.01 -3 1000 1000
3549 1234.001 1 1234 1234.0
3551 1234.01 2 1234.01 1234.01
3552 1234.01 5 1234.01 1234.01000
3554 For BigInts, no padding occurs.
3558 Number of significant digits. Leading zeros are not counted. A
3559 number may have an accuracy greater than the non-zero digits
3560 when there are zeros in it or trailing zeros. For example, 123.456 has
3561 A of 6, 10203 has 5, 123.0506 has 7, 123.450000 has 8 and 0.000123 has 3.
3563 The string output (of floating point numbers) will be padded with zeros:
3565 Initial value P A Result String
3566 ------------------------------------------------------------
3568 1234.01 6 1234.01 1234.01
3569 1234.1 8 1234.1 1234.1000
3571 For BigInts, no padding occurs.
3575 When both A and P are undefined, this is used as a fallback accuracy when
3578 =head2 Rounding mode R
3580 When rounding a number, different 'styles' or 'kinds'
3581 of rounding are possible. (Note that random rounding, as in
3582 Math::Round, is not implemented.)
3588 truncation invariably removes all digits following the
3589 rounding place, replacing them with zeros. Thus, 987.65 rounded
3590 to tens (P=1) becomes 980, and rounded to the fourth sigdig
3591 becomes 987.6 (A=4). 123.456 rounded to the second place after the
3592 decimal point (P=-2) becomes 123.46.
3594 All other implemented styles of rounding attempt to round to the
3595 "nearest digit." If the digit D immediately to the right of the
3596 rounding place (skipping the decimal point) is greater than 5, the
3597 number is incremented at the rounding place (possibly causing a
3598 cascade of incrementation): e.g. when rounding to units, 0.9 rounds
3599 to 1, and -19.9 rounds to -20. If D < 5, the number is similarly
3600 truncated at the rounding place: e.g. when rounding to units, 0.4
3601 rounds to 0, and -19.4 rounds to -19.
3603 However the results of other styles of rounding differ if the
3604 digit immediately to the right of the rounding place (skipping the
3605 decimal point) is 5 and if there are no digits, or no digits other
3606 than 0, after that 5. In such cases:
3610 rounds the digit at the rounding place to 0, 2, 4, 6, or 8
3611 if it is not already. E.g., when rounding to the first sigdig, 0.45
3612 becomes 0.4, -0.55 becomes -0.6, but 0.4501 becomes 0.5.
3616 rounds the digit at the rounding place to 1, 3, 5, 7, or 9 if
3617 it is not already. E.g., when rounding to the first sigdig, 0.45
3618 becomes 0.5, -0.55 becomes -0.5, but 0.5501 becomes 0.6.
3622 round to plus infinity, i.e. always round up. E.g., when
3623 rounding to the first sigdig, 0.45 becomes 0.5, -0.55 becomes -0.5,
3624 and 0.4501 also becomes 0.5.
3628 round to minus infinity, i.e. always round down. E.g., when
3629 rounding to the first sigdig, 0.45 becomes 0.4, -0.55 becomes -0.6,
3630 but 0.4501 becomes 0.5.
3634 round to zero, i.e. positive numbers down, negative ones up.
3635 E.g., when rounding to the first sigdig, 0.45 becomes 0.4, -0.55
3636 becomes -0.5, but 0.4501 becomes 0.5.
3640 round up if the digit immediately to the right of the rounding place
3641 is 5 or greater, otherwise round down. E.g., 0.15 becomes 0.2 and
3646 The handling of A & P in MBI/MBF (the old core code shipped with Perl
3647 versions <= 5.7.2) is like this:
3653 * ffround($p) is able to round to $p number of digits after the decimal
3655 * otherwise P is unused
3657 =item Accuracy (significant digits)
3659 * fround($a) rounds to $a significant digits
3660 * only fdiv() and fsqrt() take A as (optional) paramater
3661 + other operations simply create the same number (fneg etc), or more (fmul)
3663 + rounding/truncating is only done when explicitly calling one of fround
3664 or ffround, and never for BigInt (not implemented)
3665 * fsqrt() simply hands its accuracy argument over to fdiv.
3666 * the documentation and the comment in the code indicate two different ways
3667 on how fdiv() determines the maximum number of digits it should calculate,
3668 and the actual code does yet another thing
3670 max($Math::BigFloat::div_scale,length(dividend)+length(divisor))
3672 result has at most max(scale, length(dividend), length(divisor)) digits
3674 scale = max(scale, length(dividend)-1,length(divisor)-1);
3675 scale += length(divisor) - length(dividend);
3676 So for lx = 3, ly = 9, scale = 10, scale will actually be 16 (10+9-3).
3677 Actually, the 'difference' added to the scale is calculated from the
3678 number of "significant digits" in dividend and divisor, which is derived
3679 by looking at the length of the mantissa. Which is wrong, since it includes
3680 the + sign (oops) and actually gets 2 for '+100' and 4 for '+101'. Oops
3681 again. Thus 124/3 with div_scale=1 will get you '41.3' based on the strange
3682 assumption that 124 has 3 significant digits, while 120/7 will get you
3683 '17', not '17.1' since 120 is thought to have 2 significant digits.
3684 The rounding after the division then uses the remainder and $y to determine
3685 wether it must round up or down.
3686 ? I have no idea which is the right way. That's why I used a slightly more
3687 ? simple scheme and tweaked the few failing testcases to match it.
3691 This is how it works now:
3695 =item Setting/Accessing
3697 * You can set the A global via C<< Math::BigInt->accuracy() >> or
3698 C<< Math::BigFloat->accuracy() >> or whatever class you are using.
3699 * You can also set P globally by using C<< Math::SomeClass->precision() >>
3701 * Globals are classwide, and not inherited by subclasses.
3702 * to undefine A, use C<< Math::SomeCLass->accuracy(undef); >>
3703 * to undefine P, use C<< Math::SomeClass->precision(undef); >>
3704 * Setting C<< Math::SomeClass->accuracy() >> clears automatically
3705 C<< Math::SomeClass->precision() >>, and vice versa.
3706 * To be valid, A must be > 0, P can have any value.
3707 * If P is negative, this means round to the P'th place to the right of the
3708 decimal point; positive values mean to the left of the decimal point.
3709 P of 0 means round to integer.
3710 * to find out the current global A, use C<< Math::SomeClass->accuracy() >>
3711 * to find out the current global P, use C<< Math::SomeClass->precision() >>
3712 * use C<< $x->accuracy() >> respective C<< $x->precision() >> for the local
3713 setting of C<< $x >>.
3714 * Please note that C<< $x->accuracy() >> respective C<< $x->precision() >>
3715 return eventually defined global A or P, when C<< $x >>'s A or P is not
3718 =item Creating numbers
3720 * When you create a number, you can give it's desired A or P via:
3721 $x = Math::BigInt->new($number,$A,$P);
3722 * Only one of A or P can be defined, otherwise the result is NaN
3723 * If no A or P is give ($x = Math::BigInt->new($number) form), then the
3724 globals (if set) will be used. Thus changing the global defaults later on
3725 will not change the A or P of previously created numbers (i.e., A and P of
3726 $x will be what was in effect when $x was created)
3727 * If given undef for A and P, B<no> rounding will occur, and the globals will
3728 B<not> be used. This is used by subclasses to create numbers without
3729 suffering rounding in the parent. Thus a subclass is able to have it's own
3730 globals enforced upon creation of a number by using
3731 C<< $x = Math::BigInt->new($number,undef,undef) >>:
3733 use Math::BigInt::SomeSubclass;
3736 Math::BigInt->accuracy(2);
3737 Math::BigInt::SomeSubClass->accuracy(3);
3738 $x = Math::BigInt::SomeSubClass->new(1234);
3740 $x is now 1230, and not 1200. A subclass might choose to implement
3741 this otherwise, e.g. falling back to the parent's A and P.
3745 * If A or P are enabled/defined, they are used to round the result of each
3746 operation according to the rules below
3747 * Negative P is ignored in Math::BigInt, since BigInts never have digits
3748 after the decimal point
3749 * Math::BigFloat uses Math::BigInt internally, but setting A or P inside
3750 Math::BigInt as globals does not tamper with the parts of a BigFloat.
3751 A flag is used to mark all Math::BigFloat numbers as 'never round'.
3755 * It only makes sense that a number has only one of A or P at a time.
3756 If you set either A or P on one object, or globally, the other one will
3757 be automatically cleared.
3758 * If two objects are involved in an operation, and one of them has A in
3759 effect, and the other P, this results in an error (NaN).
3760 * A takes precedence over P (Hint: A comes before P).
3761 If neither of them is defined, nothing is used, i.e. the result will have
3762 as many digits as it can (with an exception for fdiv/fsqrt) and will not
3764 * There is another setting for fdiv() (and thus for fsqrt()). If neither of
3765 A or P is defined, fdiv() will use a fallback (F) of $div_scale digits.
3766 If either the dividend's or the divisor's mantissa has more digits than
3767 the value of F, the higher value will be used instead of F.
3768 This is to limit the digits (A) of the result (just consider what would
3769 happen with unlimited A and P in the case of 1/3 :-)
3770 * fdiv will calculate (at least) 4 more digits than required (determined by
3771 A, P or F), and, if F is not used, round the result
3772 (this will still fail in the case of a result like 0.12345000000001 with A
3773 or P of 5, but this can not be helped - or can it?)
3774 * Thus you can have the math done by on Math::Big* class in two modi:
3775 + never round (this is the default):
3776 This is done by setting A and P to undef. No math operation
3777 will round the result, with fdiv() and fsqrt() as exceptions to guard
3778 against overflows. You must explicitly call bround(), bfround() or
3779 round() (the latter with parameters).
3780 Note: Once you have rounded a number, the settings will 'stick' on it
3781 and 'infect' all other numbers engaged in math operations with it, since
3782 local settings have the highest precedence. So, to get SaferRound[tm],
3783 use a copy() before rounding like this:
3785 $x = Math::BigFloat->new(12.34);
3786 $y = Math::BigFloat->new(98.76);
3787 $z = $x * $y; # 1218.6984
3788 print $x->copy()->fround(3); # 12.3 (but A is now 3!)
3789 $z = $x * $y; # still 1218.6984, without
3790 # copy would have been 1210!
3792 + round after each op:
3793 After each single operation (except for testing like is_zero()), the
3794 method round() is called and the result is rounded appropriately. By
3795 setting proper values for A and P, you can have all-the-same-A or
3796 all-the-same-P modes. For example, Math::Currency might set A to undef,
3797 and P to -2, globally.
3799 ?Maybe an extra option that forbids local A & P settings would be in order,
3800 ?so that intermediate rounding does not 'poison' further math?
3802 =item Overriding globals
3804 * you will be able to give A, P and R as an argument to all the calculation
3805 routines; the second parameter is A, the third one is P, and the fourth is
3806 R (shift right by one for binary operations like badd). P is used only if
3807 the first parameter (A) is undefined. These three parameters override the
3808 globals in the order detailed as follows, i.e. the first defined value
3810 (local: per object, global: global default, parameter: argument to sub)
3813 + local A (if defined on both of the operands: smaller one is taken)
3814 + local P (if defined on both of the operands: bigger one is taken)
3818 * fsqrt() will hand its arguments to fdiv(), as it used to, only now for two
3819 arguments (A and P) instead of one
3821 =item Local settings
3823 * You can set A or P locally by using C<< $x->accuracy() >> or
3824 C<< $x->precision() >>
3825 and thus force different A and P for different objects/numbers.
3826 * Setting A or P this way immediately rounds $x to the new value.
3827 * C<< $x->accuracy() >> clears C<< $x->precision() >>, and vice versa.
3831 * the rounding routines will use the respective global or local settings.
3832 fround()/bround() is for accuracy rounding, while ffround()/bfround()
3834 * the two rounding functions take as the second parameter one of the
3835 following rounding modes (R):
3836 'even', 'odd', '+inf', '-inf', 'zero', 'trunc', 'common'
3837 * you can set/get the global R by using C<< Math::SomeClass->round_mode() >>
3838 or by setting C<< $Math::SomeClass::round_mode >>
3839 * after each operation, C<< $result->round() >> is called, and the result may
3840 eventually be rounded (that is, if A or P were set either locally,
3841 globally or as parameter to the operation)
3842 * to manually round a number, call C<< $x->round($A,$P,$round_mode); >>
3843 this will round the number by using the appropriate rounding function
3844 and then normalize it.
3845 * rounding modifies the local settings of the number:
3847 $x = Math::BigFloat->new(123.456);
3851 Here 4 takes precedence over 5, so 123.5 is the result and $x->accuracy()
3852 will be 4 from now on.
3854 =item Default values
3863 * The defaults are set up so that the new code gives the same results as
3864 the old code (except in a few cases on fdiv):
3865 + Both A and P are undefined and thus will not be used for rounding
3866 after each operation.
3867 + round() is thus a no-op, unless given extra parameters A and P
3871 =head1 Infinity and Not a Number
3873 While BigInt has extensive handling of inf and NaN, certain quirks remain.
3879 These perl routines currently (as of Perl v.5.8.6) cannot handle passed
3882 te@linux:~> perl -wle 'print 2 ** 3333'
3884 te@linux:~> perl -wle 'print 2 ** 3333 == 2 ** 3333'
3886 te@linux:~> perl -wle 'print oct(2 ** 3333)'
3888 te@linux:~> perl -wle 'print hex(2 ** 3333)'
3889 Illegal hexadecimal digit 'i' ignored at -e line 1.
3892 The same problems occur if you pass them Math::BigInt->binf() objects. Since
3893 overloading these routines is not possible, this cannot be fixed from BigInt.
3895 =item ==, !=, <, >, <=, >= with NaNs
3897 BigInt's bcmp() routine currently returns undef to signal that a NaN was
3898 involved in a comparison. However, the overload code turns that into
3899 either 1 or '' and thus operations like C<< NaN != NaN >> might return
3904 C<< log(-inf) >> is highly weird. Since log(-x)=pi*i+log(x), then
3905 log(-inf)=pi*i+inf. However, since the imaginary part is finite, the real
3906 infinity "overshadows" it, so the number might as well just be infinity.
3907 However, the result is a complex number, and since BigInt/BigFloat can only
3908 have real numbers as results, the result is NaN.
3910 =item exp(), cos(), sin(), atan2()
3912 These all might have problems handling infinity right.
3918 The actual numbers are stored as unsigned big integers (with seperate sign).
3920 You should neither care about nor depend on the internal representation; it
3921 might change without notice. Use B<ONLY> method calls like C<< $x->sign(); >>
3922 instead relying on the internal representation.
3926 Math with the numbers is done (by default) by a module called
3927 C<Math::BigInt::Calc>. This is equivalent to saying:
3929 use Math::BigInt lib => 'Calc';
3931 You can change this by using:
3933 use Math::BigInt lib => 'BitVect';
3935 The following would first try to find Math::BigInt::Foo, then
3936 Math::BigInt::Bar, and when this also fails, revert to Math::BigInt::Calc:
3938 use Math::BigInt lib => 'Foo,Math::BigInt::Bar';
3940 Since Math::BigInt::GMP is in almost all cases faster than Calc (especially in
3941 math involving really big numbers, where it is B<much> faster), and there is
3942 no penalty if Math::BigInt::GMP is not installed, it is a good idea to always
3945 use Math::BigInt lib => 'GMP';
3947 Different low-level libraries use different formats to store the
3948 numbers. You should B<NOT> depend on the number having a specific format
3951 See the respective math library module documentation for further details.
3955 The sign is either '+', '-', 'NaN', '+inf' or '-inf'.
3957 A sign of 'NaN' is used to represent the result when input arguments are not
3958 numbers or as a result of 0/0. '+inf' and '-inf' represent plus respectively
3959 minus infinity. You will get '+inf' when dividing a positive number by 0, and
3960 '-inf' when dividing any negative number by 0.
3962 =head2 mantissa(), exponent() and parts()
3964 C<mantissa()> and C<exponent()> return the said parts of the BigInt such
3967 $m = $x->mantissa();
3968 $e = $x->exponent();
3969 $y = $m * ( 10 ** $e );
3970 print "ok\n" if $x == $y;
3972 C<< ($m,$e) = $x->parts() >> is just a shortcut that gives you both of them
3973 in one go. Both the returned mantissa and exponent have a sign.
3975 Currently, for BigInts C<$e> is always 0, except +inf and -inf, where it is
3976 C<+inf>; and for NaN, where it is C<NaN>; and for C<$x == 0>, where it is C<1>
3977 (to be compatible with Math::BigFloat's internal representation of a zero as
3980 C<$m> is currently just a copy of the original number. The relation between
3981 C<$e> and C<$m> will stay always the same, though their real values might
3988 sub bint { Math::BigInt->new(shift); }
3990 $x = Math::BigInt->bstr("1234") # string "1234"
3991 $x = "$x"; # same as bstr()
3992 $x = Math::BigInt->bneg("1234"); # BigInt "-1234"
3993 $x = Math::BigInt->babs("-12345"); # BigInt "12345"
3994 $x = Math::BigInt->bnorm("-0.00"); # BigInt "0"
3995 $x = bint(1) + bint(2); # BigInt "3"
3996 $x = bint(1) + "2"; # ditto (auto-BigIntify of "2")
3997 $x = bint(1); # BigInt "1"
3998 $x = $x + 5 / 2; # BigInt "3"
3999 $x = $x ** 3; # BigInt "27"
4000 $x *= 2; # BigInt "54"
4001 $x = Math::BigInt->new(0); # BigInt "0"
4003 $x = Math::BigInt->badd(4,5) # BigInt "9"
4004 print $x->bsstr(); # 9e+0
4006 Examples for rounding:
4011 $x = Math::BigFloat->new(123.4567);
4012 $y = Math::BigFloat->new(123.456789);
4013 Math::BigFloat->accuracy(4); # no more A than 4
4015 ok ($x->copy()->fround(),123.4); # even rounding
4016 print $x->copy()->fround(),"\n"; # 123.4
4017 Math::BigFloat->round_mode('odd'); # round to odd
4018 print $x->copy()->fround(),"\n"; # 123.5
4019 Math::BigFloat->accuracy(5); # no more A than 5
4020 Math::BigFloat->round_mode('odd'); # round to odd
4021 print $x->copy()->fround(),"\n"; # 123.46
4022 $y = $x->copy()->fround(4),"\n"; # A = 4: 123.4
4023 print "$y, ",$y->accuracy(),"\n"; # 123.4, 4
4025 Math::BigFloat->accuracy(undef); # A not important now
4026 Math::BigFloat->precision(2); # P important
4027 print $x->copy()->bnorm(),"\n"; # 123.46
4028 print $x->copy()->fround(),"\n"; # 123.46
4030 Examples for converting:
4032 my $x = Math::BigInt->new('0b1'.'01' x 123);
4033 print "bin: ",$x->as_bin()," hex:",$x->as_hex()," dec: ",$x,"\n";
4035 =head1 Autocreating constants
4037 After C<use Math::BigInt ':constant'> all the B<integer> decimal, hexadecimal
4038 and binary constants in the given scope are converted to C<Math::BigInt>.
4039 This conversion happens at compile time.
4043 perl -MMath::BigInt=:constant -e 'print 2**100,"\n"'
4045 prints the integer value of C<2**100>. Note that without conversion of
4046 constants the expression 2**100 will be calculated as perl scalar.
4048 Please note that strings and floating point constants are not affected,
4051 use Math::BigInt qw/:constant/;
4053 $x = 1234567890123456789012345678901234567890
4054 + 123456789123456789;
4055 $y = '1234567890123456789012345678901234567890'
4056 + '123456789123456789';
4058 do not work. You need an explicit Math::BigInt->new() around one of the
4059 operands. You should also quote large constants to protect loss of precision:
4063 $x = Math::BigInt->new('1234567889123456789123456789123456789');
4065 Without the quotes Perl would convert the large number to a floating point
4066 constant at compile time and then hand the result to BigInt, which results in
4067 an truncated result or a NaN.
4069 This also applies to integers that look like floating point constants:
4071 use Math::BigInt ':constant';
4073 print ref(123e2),"\n";
4074 print ref(123.2e2),"\n";
4076 will print nothing but newlines. Use either L<bignum> or L<Math::BigFloat>
4077 to get this to work.
4081 Using the form $x += $y; etc over $x = $x + $y is faster, since a copy of $x
4082 must be made in the second case. For long numbers, the copy can eat up to 20%
4083 of the work (in the case of addition/subtraction, less for
4084 multiplication/division). If $y is very small compared to $x, the form
4085 $x += $y is MUCH faster than $x = $x + $y since making the copy of $x takes
4086 more time then the actual addition.
4088 With a technique called copy-on-write, the cost of copying with overload could
4089 be minimized or even completely avoided. A test implementation of COW did show
4090 performance gains for overloaded math, but introduced a performance loss due
4091 to a constant overhead for all other operations. So Math::BigInt does currently
4094 The rewritten version of this module (vs. v0.01) is slower on certain
4095 operations, like C<new()>, C<bstr()> and C<numify()>. The reason are that it
4096 does now more work and handles much more cases. The time spent in these
4097 operations is usually gained in the other math operations so that code on
4098 the average should get (much) faster. If they don't, please contact the author.
4100 Some operations may be slower for small numbers, but are significantly faster
4101 for big numbers. Other operations are now constant (O(1), like C<bneg()>,
4102 C<babs()> etc), instead of O(N) and thus nearly always take much less time.
4103 These optimizations were done on purpose.
4105 If you find the Calc module to slow, try to install any of the replacement
4106 modules and see if they help you.
4108 =head2 Alternative math libraries
4110 You can use an alternative library to drive Math::BigInt via:
4112 use Math::BigInt lib => 'Module';
4114 See L<MATH LIBRARY> for more information.
4116 For more benchmark results see L<http://bloodgate.com/perl/benchmarks.html>.
4120 =head1 Subclassing Math::BigInt
4122 The basic design of Math::BigInt allows simple subclasses with very little
4123 work, as long as a few simple rules are followed:
4129 The public API must remain consistent, i.e. if a sub-class is overloading
4130 addition, the sub-class must use the same name, in this case badd(). The
4131 reason for this is that Math::BigInt is optimized to call the object methods
4136 The private object hash keys like C<$x->{sign}> may not be changed, but
4137 additional keys can be added, like C<$x->{_custom}>.
4141 Accessor functions are available for all existing object hash keys and should
4142 be used instead of directly accessing the internal hash keys. The reason for
4143 this is that Math::BigInt itself has a pluggable interface which permits it
4144 to support different storage methods.
4148 More complex sub-classes may have to replicate more of the logic internal of
4149 Math::BigInt if they need to change more basic behaviors. A subclass that
4150 needs to merely change the output only needs to overload C<bstr()>.
4152 All other object methods and overloaded functions can be directly inherited
4153 from the parent class.
4155 At the very minimum, any subclass will need to provide it's own C<new()> and can
4156 store additional hash keys in the object. There are also some package globals
4157 that must be defined, e.g.:
4161 $precision = -2; # round to 2 decimal places
4162 $round_mode = 'even';
4165 Additionally, you might want to provide the following two globals to allow
4166 auto-upgrading and auto-downgrading to work correctly:
4171 This allows Math::BigInt to correctly retrieve package globals from the
4172 subclass, like C<$SubClass::precision>. See t/Math/BigInt/Subclass.pm or
4173 t/Math/BigFloat/SubClass.pm completely functional subclass examples.
4179 in your subclass to automatically inherit the overloading from the parent. If
4180 you like, you can change part of the overloading, look at Math::String for an
4185 When used like this:
4187 use Math::BigInt upgrade => 'Foo::Bar';
4189 certain operations will 'upgrade' their calculation and thus the result to
4190 the class Foo::Bar. Usually this is used in conjunction with Math::BigFloat:
4192 use Math::BigInt upgrade => 'Math::BigFloat';
4194 As a shortcut, you can use the module C<bignum>:
4198 Also good for oneliners:
4200 perl -Mbignum -le 'print 2 ** 255'
4202 This makes it possible to mix arguments of different classes (as in 2.5 + 2)
4203 as well es preserve accuracy (as in sqrt(3)).
4205 Beware: This feature is not fully implemented yet.
4209 The following methods upgrade themselves unconditionally; that is if upgrade
4210 is in effect, they will always hand up their work:
4222 Beware: This list is not complete.
4224 All other methods upgrade themselves only when one (or all) of their
4225 arguments are of the class mentioned in $upgrade (This might change in later
4226 versions to a more sophisticated scheme):
4232 =item broot() does not work
4234 The broot() function in BigInt may only work for small values. This will be
4235 fixed in a later version.
4237 =item Out of Memory!
4239 Under Perl prior to 5.6.0 having an C<use Math::BigInt ':constant';> and
4240 C<eval()> in your code will crash with "Out of memory". This is probably an
4241 overload/exporter bug. You can workaround by not having C<eval()>
4242 and ':constant' at the same time or upgrade your Perl to a newer version.
4244 =item Fails to load Calc on Perl prior 5.6.0
4246 Since eval(' use ...') can not be used in conjunction with ':constant', BigInt
4247 will fall back to eval { require ... } when loading the math lib on Perls
4248 prior to 5.6.0. This simple replaces '::' with '/' and thus might fail on
4249 filesystems using a different seperator.
4255 Some things might not work as you expect them. Below is documented what is
4256 known to be troublesome:
4260 =item bstr(), bsstr() and 'cmp'
4262 Both C<bstr()> and C<bsstr()> as well as automated stringify via overload now
4263 drop the leading '+'. The old code would return '+3', the new returns '3'.
4264 This is to be consistent with Perl and to make C<cmp> (especially with
4265 overloading) to work as you expect. It also solves problems with C<Test.pm>,
4266 because it's C<ok()> uses 'eq' internally.
4268 Mark Biggar said, when asked about to drop the '+' altogether, or make only
4271 I agree (with the first alternative), don't add the '+' on positive
4272 numbers. It's not as important anymore with the new internal
4273 form for numbers. It made doing things like abs and neg easier,
4274 but those have to be done differently now anyway.
4276 So, the following examples will now work all as expected:
4279 BEGIN { plan tests => 1 }
4282 my $x = new Math::BigInt 3*3;
4283 my $y = new Math::BigInt 3*3;
4286 print "$x eq 9" if $x eq $y;
4287 print "$x eq 9" if $x eq '9';
4288 print "$x eq 9" if $x eq 3*3;
4290 Additionally, the following still works:
4292 print "$x == 9" if $x == $y;
4293 print "$x == 9" if $x == 9;
4294 print "$x == 9" if $x == 3*3;
4296 There is now a C<bsstr()> method to get the string in scientific notation aka
4297 C<1e+2> instead of C<100>. Be advised that overloaded 'eq' always uses bstr()
4298 for comparison, but Perl will represent some numbers as 100 and others
4299 as 1e+308. If in doubt, convert both arguments to Math::BigInt before
4300 comparing them as strings:
4303 BEGIN { plan tests => 3 }
4306 $x = Math::BigInt->new('1e56'); $y = 1e56;
4307 ok ($x,$y); # will fail
4308 ok ($x->bsstr(),$y); # okay
4309 $y = Math::BigInt->new($y);
4312 Alternatively, simple use C<< <=> >> for comparisons, this will get it
4313 always right. There is not yet a way to get a number automatically represented
4314 as a string that matches exactly the way Perl represents it.
4316 See also the section about L<Infinity and Not a Number> for problems in
4321 C<int()> will return (at least for Perl v5.7.1 and up) another BigInt, not a
4324 $x = Math::BigInt->new(123);
4325 $y = int($x); # BigInt 123
4326 $x = Math::BigFloat->new(123.45);
4327 $y = int($x); # BigInt 123
4329 In all Perl versions you can use C<as_number()> or C<as_int> for the same
4332 $x = Math::BigFloat->new(123.45);
4333 $y = $x->as_number(); # BigInt 123
4334 $y = $x->as_int(); # ditto
4336 This also works for other subclasses, like Math::String.
4338 If you want a real Perl scalar, use C<numify()>:
4340 $y = $x->numify(); # 123 as scalar
4342 This is seldom necessary, though, because this is done automatically, like
4343 when you access an array:
4345 $z = $array[$x]; # does work automatically
4349 The following will probably not do what you expect:
4351 $c = Math::BigInt->new(123);
4352 print $c->length(),"\n"; # prints 30
4354 It prints both the number of digits in the number and in the fraction part
4355 since print calls C<length()> in list context. Use something like:
4357 print scalar $c->length(),"\n"; # prints 3
4361 The following will probably not do what you expect:
4363 print $c->bdiv(10000),"\n";
4365 It prints both quotient and remainder since print calls C<bdiv()> in list
4366 context. Also, C<bdiv()> will modify $c, so be careful. You probably want
4369 print $c / 10000,"\n";
4370 print scalar $c->bdiv(10000),"\n"; # or if you want to modify $c
4374 The quotient is always the greatest integer less than or equal to the
4375 real-valued quotient of the two operands, and the remainder (when it is
4376 nonzero) always has the same sign as the second operand; so, for
4386 As a consequence, the behavior of the operator % agrees with the
4387 behavior of Perl's built-in % operator (as documented in the perlop
4388 manpage), and the equation
4390 $x == ($x / $y) * $y + ($x % $y)
4392 holds true for any $x and $y, which justifies calling the two return
4393 values of bdiv() the quotient and remainder. The only exception to this rule
4394 are when $y == 0 and $x is negative, then the remainder will also be
4395 negative. See below under "infinity handling" for the reasoning behind this.
4397 Perl's 'use integer;' changes the behaviour of % and / for scalars, but will
4398 not change BigInt's way to do things. This is because under 'use integer' Perl
4399 will do what the underlying C thinks is right and this is different for each
4400 system. If you need BigInt's behaving exactly like Perl's 'use integer', bug
4401 the author to implement it ;)
4403 =item infinity handling
4405 Here are some examples that explain the reasons why certain results occur while
4408 The following table shows the result of the division and the remainder, so that
4409 the equation above holds true. Some "ordinary" cases are strewn in to show more
4410 clearly the reasoning:
4412 A / B = C, R so that C * B + R = A
4413 =========================================================
4414 5 / 8 = 0, 5 0 * 8 + 5 = 5
4415 0 / 8 = 0, 0 0 * 8 + 0 = 0
4416 0 / inf = 0, 0 0 * inf + 0 = 0
4417 0 /-inf = 0, 0 0 * -inf + 0 = 0
4418 5 / inf = 0, 5 0 * inf + 5 = 5
4419 5 /-inf = 0, 5 0 * -inf + 5 = 5
4420 -5/ inf = 0, -5 0 * inf + -5 = -5
4421 -5/-inf = 0, -5 0 * -inf + -5 = -5
4422 inf/ 5 = inf, 0 inf * 5 + 0 = inf
4423 -inf/ 5 = -inf, 0 -inf * 5 + 0 = -inf
4424 inf/ -5 = -inf, 0 -inf * -5 + 0 = inf
4425 -inf/ -5 = inf, 0 inf * -5 + 0 = -inf
4426 5/ 5 = 1, 0 1 * 5 + 0 = 5
4427 -5/ -5 = 1, 0 1 * -5 + 0 = -5
4428 inf/ inf = 1, 0 1 * inf + 0 = inf
4429 -inf/-inf = 1, 0 1 * -inf + 0 = -inf
4430 inf/-inf = -1, 0 -1 * -inf + 0 = inf
4431 -inf/ inf = -1, 0 1 * -inf + 0 = -inf
4432 8/ 0 = inf, 8 inf * 0 + 8 = 8
4433 inf/ 0 = inf, inf inf * 0 + inf = inf
4436 These cases below violate the "remainder has the sign of the second of the two
4437 arguments", since they wouldn't match up otherwise.
4439 A / B = C, R so that C * B + R = A
4440 ========================================================
4441 -inf/ 0 = -inf, -inf -inf * 0 + inf = -inf
4442 -8/ 0 = -inf, -8 -inf * 0 + 8 = -8
4444 =item Modifying and =
4448 $x = Math::BigFloat->new(5);
4451 It will not do what you think, e.g. making a copy of $x. Instead it just makes
4452 a second reference to the B<same> object and stores it in $y. Thus anything
4453 that modifies $x (except overloaded operators) will modify $y, and vice versa.
4454 Or in other words, C<=> is only safe if you modify your BigInts only via
4455 overloaded math. As soon as you use a method call it breaks:
4458 print "$x, $y\n"; # prints '10, 10'
4460 If you want a true copy of $x, use:
4464 You can also chain the calls like this, this will make first a copy and then
4467 $y = $x->copy()->bmul(2);
4469 See also the documentation for overload.pm regarding C<=>.
4473 C<bpow()> (and the rounding functions) now modifies the first argument and
4474 returns it, unlike the old code which left it alone and only returned the
4475 result. This is to be consistent with C<badd()> etc. The first three will
4476 modify $x, the last one won't:
4478 print bpow($x,$i),"\n"; # modify $x
4479 print $x->bpow($i),"\n"; # ditto
4480 print $x **= $i,"\n"; # the same
4481 print $x ** $i,"\n"; # leave $x alone
4483 The form C<$x **= $y> is faster than C<$x = $x ** $y;>, though.
4485 =item Overloading -$x
4495 since overload calls C<sub($x,0,1);> instead of C<neg($x)>. The first variant
4496 needs to preserve $x since it does not know that it later will get overwritten.
4497 This makes a copy of $x and takes O(N), but $x->bneg() is O(1).
4499 =item Mixing different object types
4501 In Perl you will get a floating point value if you do one of the following:
4507 With overloaded math, only the first two variants will result in a BigFloat:
4512 $mbf = Math::BigFloat->new(5);
4513 $mbi2 = Math::BigInteger->new(5);
4514 $mbi = Math::BigInteger->new(2);
4516 # what actually gets called:
4517 $float = $mbf + $mbi; # $mbf->badd()
4518 $float = $mbf / $mbi; # $mbf->bdiv()
4519 $integer = $mbi + $mbf; # $mbi->badd()
4520 $integer = $mbi2 / $mbi; # $mbi2->bdiv()
4521 $integer = $mbi2 / $mbf; # $mbi2->bdiv()
4523 This is because math with overloaded operators follows the first (dominating)
4524 operand, and the operation of that is called and returns thus the result. So,
4525 Math::BigInt::bdiv() will always return a Math::BigInt, regardless whether
4526 the result should be a Math::BigFloat or the second operant is one.
4528 To get a Math::BigFloat you either need to call the operation manually,
4529 make sure the operands are already of the proper type or casted to that type
4530 via Math::BigFloat->new():
4532 $float = Math::BigFloat->new($mbi2) / $mbi; # = 2.5
4534 Beware of simple "casting" the entire expression, this would only convert
4535 the already computed result:
4537 $float = Math::BigFloat->new($mbi2 / $mbi); # = 2.0 thus wrong!
4539 Beware also of the order of more complicated expressions like:
4541 $integer = ($mbi2 + $mbi) / $mbf; # int / float => int
4542 $integer = $mbi2 / Math::BigFloat->new($mbi); # ditto
4544 If in doubt, break the expression into simpler terms, or cast all operands
4545 to the desired resulting type.
4547 Scalar values are a bit different, since:
4552 will both result in the proper type due to the way the overloaded math works.
4554 This section also applies to other overloaded math packages, like Math::String.
4556 One solution to you problem might be autoupgrading|upgrading. See the
4557 pragmas L<bignum>, L<bigint> and L<bigrat> for an easy way to do this.
4561 C<bsqrt()> works only good if the result is a big integer, e.g. the square
4562 root of 144 is 12, but from 12 the square root is 3, regardless of rounding
4563 mode. The reason is that the result is always truncated to an integer.
4565 If you want a better approximation of the square root, then use:
4567 $x = Math::BigFloat->new(12);
4568 Math::BigFloat->precision(0);
4569 Math::BigFloat->round_mode('even');
4570 print $x->copy->bsqrt(),"\n"; # 4
4572 Math::BigFloat->precision(2);
4573 print $x->bsqrt(),"\n"; # 3.46
4574 print $x->bsqrt(3),"\n"; # 3.464
4578 For negative numbers in base see also L<brsft|brsft>.
4584 This program is free software; you may redistribute it and/or modify it under
4585 the same terms as Perl itself.
4589 L<Math::BigFloat>, L<Math::BigRat> and L<Math::Big> as well as
4590 L<Math::BigInt::BitVect>, L<Math::BigInt::Pari> and L<Math::BigInt::GMP>.
4592 The pragmas L<bignum>, L<bigint> and L<bigrat> also might be of interest
4593 because they solve the autoupgrading/downgrading issue, at least partly.
4596 L<http://search.cpan.org/search?mode=module&query=Math%3A%3ABigInt> contains
4597 more documentation including a full version history, testcases, empty
4598 subclass files and benchmarks.
4602 Original code by Mark Biggar, overloaded interface by Ilya Zakharevich.
4603 Completely rewritten by Tels http://bloodgate.com in late 2000, 2001 - 2006
4604 and still at it in 2007.
4606 Many people contributed in one or more ways to the final beast, see the file
4607 CREDITS for an (incomplete) list. If you miss your name, please drop me a