NAME

Set::Infinite - Sets of intervals

SYNOPSIS

  use Set::Infinite;

  $a = Set::Infinite->new(1,2);
  print $a->union(5,6);

DESCRIPTION

Set::Infinite is a Set Theory module for infinite sets.

It works on reals or integers. You can provide your own objects or let it make them for you using the `type'.

It works very well on dates, providing schedule checks (intersections) and unions.

EXPORT

None by default.

USAGE

        $a = Set::Infinite->new();
        $a = Set::Infinite->new(1);
        $a = Set::Infinite->new(1,2);
        $a = Set::Infinite->new($b);
        $a = Set::Infinite->new([1], [1,2], [$b]);

Mode functions:

        $a->real;

        $a->integer;

Logic functions:

        $logic = $a->intersects($b);

        $logic = $a->contains($b);

        $logic = $a->is_null;

Set functions:

        $i = $a->union($b);     

        $i = $a->intersection($b);

        $i = $a->complement;
        $i = $a->complement($b);

        $i = $a->span;   

                result is INTERVAL, (min .. max)

Scalar functions:

        $i = $a->min;

        $i = $a->max;

        $i = $a->size;  

Perl functions:

        @b = sort @a;

        print $a;

Global functions:

        separators(@i)

                chooses the interval separators. 

                default are [ ] ( ) '..' ','.

        null($i)                

                chooses 'null' name. default is ''

        infinite($i)

                chooses 'infinite' name. default is 'inf'

        infinite

                returns an 'infinite' number.

        minus_infinite

                returns '-infinite' number.

        null

                returns the 'null' object.

        quantize( parameters )

                Makes equal-sized subsets.

                In array context: returns a tied reference to the subset list.
                In set context: returns an ordered set of equal-sized subsets.

                The quantization function is external to this module:
                Parameters may vary depending on implementation. 

                Positions for which a subset does not exist may show as null.

                Example: 

                        $a = Set::Infinite->new([1,3]);
                        print join (" ", $a->quantize( quant => 1 ) );

                Gives: 

                        [1..2) [2..3) [3..4)

        select( parameters )

                Selects set members based on their ordered positions.
                Selection is more useful after quantization.

                In array context: returns a tied reference to the array of selected subsets.
                In set context: returns the set of selected subsets.

                Unselected subsets may show as null.

                The selection function is external to this module:
                Parameters may vary depending on implementation. 

                        freq     - default=1
                        by       - default=[0]
                        count    - dafault=infinite

        offset ( parameters )

                Offsets the subsets. Parameters: 

                        value   - default=[0,0]
                        mode    - default='offset'. Possible values are: 'offset', 'begin', 'end'.
                        unit    - type of value. Can be 'days', 'weeks', 'hours', 'minutes', 'seconds'.

        iterate ( sub { } )

                EXPERIMENTAL - may be removed in next release
                Iterates over a subroutine. 
                Returns the union of partial results.

        type($i)

                chooses an object data type. 

                default is none (a normal perl SCALAR).

                examples: 

                type('Math::BigFloat');
                type('Math::BigInt');
                type('Set::Infinite::Date');
                        See notes on Set::Infinite::Date below.

        tolerance(0)    defaults to real sets (default)
        tolerance(1)    defaults to integer sets

        real                    defaults to real sets (default)

        integer                 defaults to integer sets

Internal functions:

        $a->cleanup;

        $a->add($b);  # Use $a = $a->union($b) instead.

        $a->backtrack($b);

Notes on Dates

Set::Infinite::Date and Set::Infinite::ICal are Date "plugins" for sets.

** NOTE ** Set::Infinite::ICal is still experimental

use:

        type('Set::Infinite::Date');  # 2001-05-02 10:00:00   
        # or
        type('Set::Infinite::ICal');  # 20010502T100000Z

Both require Time::Local. Set::Infinite::ICal requires Date::ICal.

They change quantize function behaviour to accept time units:

        use Set::Infinite;
        use Set::Infinite::Quantize_Date;
        Set::Infinite->type('Set::Infinite::Date');
        Set::Infinite::Date->date_format("year-month-day");

        $a = Set::Infinite->new('2001-05-02', '2001-05-13');
        print "Weeks in $a: ", join (" ", $a->quantize(unit => 'weeks', quant => 1) );

        $a = Set::Infinite->new('09:30', '10:35');
        print "Quarters of hour in $a: ", join (" ", $a->quantize(unit => 'minutes', quant => 15) );

Quantize units can be years, months, days, weeks, hours, minutes, or seconds. To quantize the year to first-week-of-year until last-week-of-year, use 'weekyears':

                ->quantize( unit => weekyears, wkst => 1 )

'wkst' parameter is '1' for monday (default), '7' for sunday.

max and min functions will also show in date/time format.

CAVEATS

        $a = Set::Infinite->new(10,1);
                Will be interpreted as [1..10]

        $a = Set::Infinite->new(1,2,3,4);
                Will be interpreted as [1..2],[3..4] instead of [1,2,3,4].
                You probably want ->new([1],[2],[3],[4]) instead,
                or maybe ->new(1,4) 

        $a = Set::Infinite->new(1..3);
                Will be interpreted as [1..2],3 instead of [1,2,3].
                You probably want ->new(1,3) instead.

AUTHOR

        Flavio Soibelmann Glock <fglock@pucrs.br>

cpanm Set::Infinite

perl -MCPAN -e shell
install Set::Infinite