## SYNOPSIS

use Number::Fraction;

my $f1 = Number::Fraction->new(1, 2);

my $f2 = Number::Fraction->new('1/2');

my $f3 = Number::Fraction->new($f1); # clone

my $f4 = Number::Fraction->new; # 0/1

or

use Number::Fraction ':constants'; my $f1 = '1/2'; my $f2 = $f1; my $one = $f1 + $f2; my $half = $one - $f1; print $half; # prints '1/2'

## ABSTRACT

Number::Fraction is a Perl module which allows you to work with fractions in your Perl programs.## DESCRIPTION

Number::Fraction allows you to work with fractions (i.e. rational numbers) in your Perl programs in a very natural way.It was originally written as a demonstration of the techniques of overloading.

If you use the module in your program in the usual way

use Number::Fraction;

you can then create fraction objects using `"Number::Fraction-"`new> in
a number of ways.

my $f1 = Number::Fraction->new(1, 2);

creates a fraction with a numerator of 1 and a denominator of 2.

my $f2 = Number::Fraction->new('1/2');

does the same thing but from a string constant.

my $f3 = Number::Fraction->new($f1);

makes `$f3` a copy of `$f1`

my $f4 = Number::Fraction->new; # 0/1

creates a fraction with a denominator of 0 and a numerator of 1.

If you use the alterative syntax of

use Number::Fraction ':constants';

then Number::Fraction will automatically create fraction objects from
string constants in your program. Any time your program contains a
string constant of the form `"\d+/\d+"` then that will be automatically
replaced with the equivalent fraction object. For example

my $f1 = '1/2';

Having created fraction objects you can manipulate them using most of the normal mathematical operations.

my $one = $f1 + $f2; my $half = $one - $f1;

Additionally, whenever a fraction object is evaluated in a string context, it will return a string in the format x/y. When a fraction object is evaluated in a numerical context, it will return a floating point representation of its value.

Fraction objects will always ``normalise'' themselves. That is, if you create a fraction of '2/4', it will silently be converted to '1/2'.

## Experimental Support for Exponentiation

Version 1.13 of Number::Fraction adds experimental support for exponentiation operations. If a Number::Fraction object is used as the left hand operand of an exponentiation expression then the value returned will be another Number::Fraction object - if that makes sense. In all other cases, the expression returns a real number.Currently this only works if the right hand operand is an integer (or a Number::Fraction object that has a denominator of 1). Later I hope to extend this so support so that a Number::Fraction object is returned whenever the result of the expression is a rational number.

For example:

'1/2' ** 2 # Returns a Number::Fraction ('1/4') '2/1' ** '2/1' Returns a Number::Fraction ('4/1') '2/1' ** '1/2' Returns a real number (1.414213) 0.5 ** '2/1' Returns a real number (0.25)

## Version 2: Now With Added Moose

Version 2 of Number::Fraction has been reimplemented using Moose. You should see very little difference in the way that the class works. The only difference I can see is that`"new"`used to return

`"undef"`if it couldn't create a valid object from its arguments, it now dies. If you aren't sure of the values that are being passed into the constructor, then you'll want to call it within an

`"eval { ... }"`block (or using something equivalent like Try::Tiny).

## METHODS

## import

Called when module is`"use"`d. Use to optionally install constant handler.

## unimport

Be a good citizen and uninstall constant handler when caller uses`"no Number::Fraction"`.

## BUILDARGS

Parameter massager for Number::Fraction object. Takes the following kinds of parameters:- A single Number::Fraction object which is cloned.
- A string in the form 'x/y' where x and y are integers. x is used as the numerator and y is used as the denominator of the new object.
- Two integers which are used as the numerator and denominator of the new object.
- A single integer which is used as the numerator of the the new object. The denominator is set to 1.
- No arguments, in which case a numerator of 0 and a denominator of 1 are used.

Dies if a Number::Fraction object can't be created.

## BUILD

Object initialiser for Number::Fraction. Ensures that fractions are in a normalised format.## to_string

Returns a string representation of the fraction in the form ``numerator/denominator''.## to_num

Returns a numeric representation of the fraction by calculating the sum numerator/denominator. Normal caveats about the precision of floating point numbers apply.## add

Add a value to a fraction object and return a new object representing the result of the calculation.The first parameter is a fraction object. The second parameter is either another fraction object or a number.

## mult

Multiply a fraction object by a value and return a new object representing the result of the calculation.The first parameter is a fraction object. The second parameter is either another fraction object or a number.

## subtract

Subtract a value from a fraction object and return a new object representing the result of the calculation.The first parameter is a fraction object. The second parameter is either another fraction object or a number.

## div

Divide a fraction object by a value and return a new object representing the result of the calculation.## exp

Raise a Number::Fraction object to a power.The first argument is a number fraction object. The second argument is another Number::Fraction object or a number. If the second argument is an integer or a Number::Fraction object containing an integer then the value returned is a Number::Fraction object, otherwise the value returned is a real number.

## abs

Returns a copy of the given object with both the numerator and denominator changed to positive values.## EXPORT

None by default.## AUTHOR

Dave Cross, <[email protected]>## COPYRIGHT AND LICENSE

Copyright 2002-8 by Dave CrossThis library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.