com.comcast.ip4s

An instance is available for any effect which has a Sync instance.

A hostname contains one or more labels, where each label consists of letters A-Z, a-z, digits 0-9, or a dash.
A label may not start or end in a dash and may not exceed 63 characters in length. Labels are separated by
periods and the overall hostname must not exceed 253 characters in length.

This type models internationalized hostnames. An IDN provides unicode labels, a unicode string form,
and an ASCII hostname form.

A well formed IDN consists of one or more labels separated by dots. Each label may contain unicode characters
as long as the converted ASCII form meets the requirements of RFC1123 (e.g., 63 or fewer characters and no
leading or trailing dash). A dot is represented as an ASCII period or one of the unicode dots: full stop,
ideographic full stop, fullwidth full stop, halfwidth ideographic full stop.

The toString method returns the IDN in the form in which it was constructed. Sometimes it is useful to
normalize the IDN -- converting all dots to an ASCII period and converting all labels to lowercase.

Note: equality and comparison of IDNs is case-sensitive. Consider comparing normalized toString values
for a more lenient notion of equality.

=== Construction ===

IpAddress instances are constructed in a few different ways:
- via IpAddress("127.0.0.1"), which parses a string representation of the IP and returns an Option[IpAddress]
- via IpAddress.fromBytes(arr), which returns an IP address if the supplied array is either exactly 4 bytes or exactly 16 bytes
- via literal syntax like ip"127.0.0.1", which returns an IpAddress and fails to compile if the IP is invalid.

=== Type Hierarchy ===

There are two subtypes of IpAddress -- Ipv4Address and Ipv6Address. Each of these subtypes have a richer
API than IpAddress and it is often useful to use those types directly, for example if your use case requires a V6 address.
It is safe to pattern match on IpAddress to access Ipv4Address or Ipv6Address directly, or alternatively, you can use fold.

=== JVM Specific API ===

If using IpAddress on the JVM, you can call toInetAddress to convert the address to a java.net.InetAddress, for use
with networking libraries. This method does not exist on the Scala.js version.

An instance of Multicast is typically created by either calling Multicast.apply or by using
the asMulticast method on IpAddress.

This is represented as an ADT consisting of two constructors, AnySourceMulticastJoin and
SourceSpecificMulticastJoin. These constructors are provided as top level types to allow
domain modeling where a specific join type is required. The address type is parameterized for
a similar reason -- to allow domain modeling where a specific address type is required.

An instance of SourceSpecificMulticast is typically created by either calling Multicast.apply
or by using the asSourceSpecificMulticast method on IpAddress.