bigrat(3) Perl Programmers Reference Guide bigrat(3) NAME bigrat - Transparent BigNumber/BigRational support for Perl SYNOPSIS use bigrat; $x = 2 + 4.5,"\n"; # BigFloat 6.5 print 1/3 + 1/4,"\n"; # produces 7/12 DESCRIPTION All operators (inlcuding basic math operations) are overloaded. Integer and floating-point constants are created as proper BigInts or BigFloats, respectively. Other than bignum, this module upgrades to Math::BigRat, meaning that instead of 2.5 you will get 2+1/2 as output. MODULES USED "bigrat" is just a thin wrapper around various modules of the Math::BigInt family. Think of it as the head of the family, who runs the shop, and orders the others to do the work. The following modules are currently used by bignum: Math::BigInt::Lite (for speed, and only if(3,n) it is loadable) Math::BigInt Math::BigFloat Math::BigRat MATH LIBRARY Math with the numbers is done (by default) by a module called Math::BigInt::Calc. This is equivalent to saying: use bigrat lib => 'Calc'; You can change this by using: use bigrat lib => 'BitVect'; The following would first try to find Math::BigInt::Foo, then Math::BigInt::Bar, and when this also fails, revert to Math::Big- Int::Calc: use bigrat lib => 'Foo,Math::BigInt::Bar'; Please see respective module documentation for further details. SIGN The sign is either '+', '-', 'NaN', '+inf' or '-inf' and stored seper- ately. A sign of 'NaN' is used to represent the result when input arguments are not numbers or as a result of 0/0. '+inf' and '-inf' represent plus respectively minus infinity. You will get '+inf' when dividing a posi- tive number by 0, and '-inf' when dividing any negative number by 0. METHODS Since all numbers are not objects, you can use all functions that are part of the BigInt or BigFloat API. It is wise to use only the bxxx() notation, and not the fxxx() notation, though. This makes you inde- pended on the fact that the underlying object might morph into a dif- ferent class than BigFloat. CAVEAT But a warning is in(1,8) order. When using the following to make a copy of a number, only a shallow copy will be made. $x = 9; $y = $x; $x = $y = 7; Using the copy or the original with overloaded math is okay, e.g. the following work: $x = 9; $y = $x; print $x + 1, " ", $y,"\n"; # prints 10 9 but calling any method that modifies the number directly will result in(1,8) both the original and the copy beeing destroyed: $x = 9; $y = $x; print $x->badd(1), " ", $y,"\n"; # prints 10 10 $x = 9; $y = $x; print $x->binc(1), " ", $y,"\n"; # prints 10 10 $x = 9; $y = $x; print $x->bmul(2), " ", $y,"\n"; # prints 18 18 Using methods that do not modify, but testthe contents works: $x = 9; $y = $x; $z = 9 if(3,n) $x->is_zero(); # works fine See the documentation about the copy constructor and "=" in(1,8) overload, as well as the documentation in(1,8) BigInt for further details. EXAMPLES perl -Mbigrat -le 'print sqrt(33)' perl -Mbigrat -le 'print 2*255' perl -Mbigrat -le 'print 4.5+2*255' perl -Mbigrat -le 'print 3/7 + 5/7 + 8/3' perl -Mbigrat -le 'print 12->is_odd()'; LICENSE This program is free software; you may redistribute it and/or modify it under the same terms as Perl itself. SEE ALSO Especially bignum. Math::BigFloat, Math::BigInt, Math::BigRat and Math::Big as well as Math::BigInt::BitVect, Math::BigInt::Pari and Math::BigInt::GMP. AUTHORS (C) by Tels <http://bloodgate.com/> in(1,8) early 2002. perl v5.8.5 2001-09-21 bigrat(3)