Ricardo SIGNES > Number-Tolerant > Number::Tolerant::Union
Module Version: 1.708

# NAME

Number::Tolerant::Union - unions of tolerance ranges

version 1.708

# SYNOPSIS

``` use Number::Tolerant;

my \$range1 = tolerance(10 => to => 12);
my \$range2 = tolerance(14 => to => 16);

my \$union = \$range1 | \$range2;

if (\$11 == \$union) { ... } # this will happen
if (\$12 == \$union) { ... } # so will this

if (\$13 == \$union) { ... } # nothing will happen here

if (\$14 == \$union) { ... } # this will happen
if (\$15 == \$union) { ... } # so will this```

# DESCRIPTION

Number::Tolerant::Union is used by Number::Tolerant to represent the union of multiple tolerances. A subset of the same operators that function on a tolerance will function on a union of tolerances, as listed below.

# METHODS

## new

`  my \$union = Number::Tolerant::Union->new(@list_of_tolerances);`

There is a `new` method on the Number::Tolerant::Union class, but unions are meant to be created with the `|` operator on a Number::Tolerant tolerance.

The arguments to `new` are a list of numbers or tolerances to be unioned.

Intersecting ranges are not converted into a single range, but this may change in the future. (For example, the union of "5 to 10" and "7 to 12" is not "5 to 12.")

## options

This method will return a list of all the acceptable options for the union.

Tolerance unions overload a few operations, mostly comparisons.

numification

Unions numify to undef. If there's a better idea, I'd love to hear it.

stringification

A tolerance stringifies to a short description of itself. This is a set of the union's options, parentheses-enclosed and joined by the word "or"

equality

A number is equal to a union if it is equal to any of its options.

comparison

A number is greater than a union if it is greater than all its options.

A number is less than a union if it is less than all its options.

union intersection

An intersection (`&`) with a union is commutted across all options. In other words:

` (a | b | c) & d  ==yields==> ((a & d) | (b & d) | (c & d))`

Options that have no intersection with the new element are dropped. The intersection of a constant number and a union yields that number, if the number was in the union's ranges and otherwise yields nothing.

# TODO

Who knows. Collapsing overlapping options, probably.

# AUTHOR

Ricardo Signes <rjbs@cpan.org>