NAME

Set::Infinite - Sets of intervals

SYNOPSIS

  use Set::Infinite;

  $a = Set::Infinite->new(1,2);    # [1..2]
  print $a->union(5,6);            # [1..2],[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), unions, and infinite recurrences.

METHODS

is_too_complex

Sometimes a set might be too complex to print. It will happen when you ask for a quantization on a set bounded by -inf or inf.

until

Extends a set until another:

    0,5,7 -> until 2,6,10

gives

    [0..2), [5..6), [7..10)

Note: this function is still experimental.

copy

Makes a new object from the object's data.

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;  

Overloaded Perl functions:

    print    

    sort, <=> 

Global functions:

    separators(@i)

        chooses the interval separators. 

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

    infinite($i)

        chooses 'infinite' name. default is 'inf'

    inf

        returns an 'Infinity' number.

    minus_inf

        returns '-Infinity' number.

    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 undef.

        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).

            freq     - default=1
            by       - default=[0]
            count    - default=Infinity

 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15    # [0..15] quantized by "1"

 0              5             10             15    # freq => 5

    1     3        6     8       11    13          # freq => 5, by => [ -2, 1 ]

    1     3        6     8                         # freq => 5, by => [ -2, 1 ], count => 2

    1                                     14       # by => [ -2, 1 ]

    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 { } )

        Iterates over a subroutine. 
        Returns the union of partial results.

    first

        In scalar context returns the first interval of a set.

        In list context returns the first interval of a set, and the
        'tail'.

        Works in unbounded sets

    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;

    $a->backtrack($b);

    $a->fixtype; 

    $a->numeric;

Notes on Dates

See module Date::Set for up-to-date information on date-sets.

Set::Infinite::Date is a Date "plug-in" for sets.

usage:

    type('Set::Infinite::Date');  # allows values like '2001-05-02 10:00:00'

Set::Infinite::Date requires Time::Local.

    use Set::Infinite;
    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: ", $a->quantize(unit => 'weeks', quant => 1);

    $a = Set::Infinite->new('09:30', '10:35');
    print "Quarters of hour in $a: ", $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.

SEE ALSO

    Date::Set

    the Reefknot project <http://reefknot.sf.net>

AUTHOR

    Flavio Soibelmann Glock <fglock@pucrs.br>

cpanm Set::Infinite

perl -MCPAN -e shell
install Set::Infinite