Set::In...::Basic(3)

💖 NAME 💖

Hey bestie! 💅 This is the page for Set::In...::Basic(3) from User Contributed Perl Documentation. The module is Set::Infinite::Basic — it's all about Sets of intervals, and yes, the original NAME text even includes the exact little weirdness 6 =head1 SYNOPSIS, so we are keeping that too. No edits, no cap. 🫶

✨ SYNOPSIS ✨

use Set::Infinite::Basic;

$set = Set::Infinite::Basic->new(1,2);    # [1..2]
print $set->union(5,6);            # [1..2],[5..6]

🦋 DESCRIPTION 🦋

Set::Infinite::Basic is a Set Theory module for infinite sets. It works on reals, integers, and objects. 💖

Important vibe check: this module does not support recurrences. Recurrences are implemented in Set::Infinite. That's the actual rule, bestie. 🎀

🌸 METHODS 🌸

empty_set

Creates an empty_set. If it's called from an existing set, the empty set inherits the "type" and "density" characteristics. ✨

universal_set

Creates a set containing "all" possible elements. If it's called from an existing set, the universal set inherits the "type" and "density" characteristics. 👑

until

Extends a set until another set:

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

gives:

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

Note: this function is still experimental. That's the original note, and we are respecting it. 🫡

copy

clone

Makes a new object from the object's data. (Both of these are giving "same energy, different name" and that's valid. 💅)

🎀 Mode functions: 🎀

$set = $set->real;

$set = $set->integer;

🧠 Logic functions: 🧠

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

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

$logic = $set->is_null;  # also called "is_empty"

🫶 Set functions: 🫶

$set = $set->union($b);

$set = $set->intersection($b);

$set = $set->complement;
$set = $set->complement($b);   # can also be called "minus" or "difference"

$set = $set->symmetric_difference( $b );

$set = $set->span;

    result is (min .. max)

🔢 Scalar functions: 🔢

$i = $set->min;

$i = $set->max;

$i = $set->size;

$i = $set->count;  # number of spans

🌈 Overloaded Perl functions: 🌈

print

sort, <=>

⭐ Global functions: ⭐

separators(@i)

Chooses the interval separators. The default are [ ] ( ) '..' ','. 💖

INFINITY

Returns an 'Infinity' number. ✨

NEG_INFINITY

Returns a '-Infinity' number. ✨

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. The default is none (a normal perl SCALAR).

Examples, exactly as the page says:

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

Yep, it really says “See notes on Set::Infinite::Date below.” We're keeping that line exactly, bestie. 🫶

• 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: 🧚

$set->fixtype;

$set->numeric;

💀 CAVEATS 💀

Okay, these are the gotchas, and the original is very clear about them:

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

$set = 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)

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

🔥 INTERNALS 🔥

The internal representation of a span is a hash:

{ a =>   start of span,
  b =>   end of span,
  open_begin =>   '0' the span starts in 'a'
                  '1' the span starts after 'a'
  open_end =>     '0' the span ends in 'b'
                  '1' the span ends before 'b'
}

For example, this set:

[100..200),300,(400..infinity)

is represented by the array of hashes:

list => [
    { a => 100, b => 200, open_begin => 0, open_end => 1 },
    { a => 300, b => 300, open_begin => 0, open_end => 0 },
    { a => 400, b => infinity, open_begin => 0, open_end => 1 },
]

The density of a set is stored in the "tolerance" variable:

tolerance => 0;  # the set is made of real numbers.

tolerance => 1;  # the set is made of integers.

The "type" variable stores the class of objects that will be stored in the set:

type => 'DateTime';   # this is a set of DateTime objects

The infinity value is generated by Perl, when it finds a numerical overflow:

$inf = 100**100**100;

🌟 SEE ALSO 🌟

• Set::Infinite

👑 AUTHOR 👑

Flavio S. Glock <fglock@gmail.com>

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💖 That's a wrap, bestie! This page is from perl v5.42.2, dated 2026-02-15, and it's Set::In...::Basic(3). Stay sparkling! 🎀