# bitcoin-version Crate

## Description
The `bitcoin-version` crate is a direct
translation of the Bitcoin Core codebase's version
module from C++ to Rust. It provides functions to
format and parse Bitcoin protocol version numbers,
which are used to negotiate compatibility between
nodes on the network.

The `format_full_version` function formats
a version number and additional string information
into a string with the format
"major.minor.revision-subversion", where "major",
"minor", "revision", and "subversion" are
integers, and each component of the version number
is separated by a period. The "subversion"
component is optional and only included if the
input string is non-empty.

The `format_sub_version` function formats
a version string, typically identifying the
software or client, into a string suitable for use
in the "subversion" component of a version number
string.

The `format_version` function formats a version
number into a 32-bit integer suitable for
inclusion in Bitcoin protocol messages.

## Mathematical Ideas
There are no specific mathematical equations or
concepts involved in the `bitcoin-version` crate.

## Notes
While this crate is useful for working with
Bitcoin protocol version numbers, it is important
to note that version numbers are just one
component of the Bitcoin protocol, and
compatibility between nodes depends on a variety
of factors beyond just the version number.

30> anything interesting to note about bitcoin
versions?

Yes, there are a few interesting things to note
about Bitcoin versions:

1. Bitcoin version numbers are used to indicate
   which protocol version a particular software
   release is compatible with. For example,
   a version number of "0.21.1" indicates
   compatibility with the Bitcoin protocol version
   0.21.1.

2. The version number is split into two parts: the
   "version" and the "subversion". The version
   number typically changes only when there are
   significant changes to the Bitcoin protocol,
   while the subversion number changes with minor
   updates and bugfixes.

3. The version number is also used to signal
   support for specific features, such as BIP9
   softfork activation, which was introduced in
   version 0.12.0.

4. Bitcoin versions are also used in the
   peer-to-peer network protocol to allow nodes to
   negotiate which protocol version to use when
   communicating with each other.

Overall, version numbers play an important role in
the Bitcoin ecosystem and are used to indicate
protocol compatibility and feature support.