PGVersion: a class to manage PostgreSQL Version (strings) within a Perl 6 Program

As you probably already know, PostgreSQL has changed its versioning number scheme from a major.major.minor approach to a concise major.minor one. Both are simple enought to be evaluated with a regular expression, but I found myself wrinting the same logic over and over, so I decided to write a minimal class to do the job for me and provide several information.
Oh, and this is Perl 6 (that I’m still learning!).
The class is named Fluca1978::Utils::PostgreSQL::PGVersion and is released as it is under the BSD Licence.

Quick, show me something!

Ok, here it is how it works: The above simple loop provides the following output: As you can see, every version string is correctly interpreted and printed out, major and minor numbering schemes are applied depending on the version number recognized.

From a string to a string

The class provides three stringify methods:

• .gist provides the numeric part of the version number, e.g., 9.6.5;
• .Str places a v (for version) in front of the numeric part of the string, e.g., v9.6.5;
• .Str( Bool ) when passed a True value produces a verbose output explaining the version of PostgreSQL including its alfa or beta status (e.g., 9.6.5 (Major: 9.6, Minor: 5, stable)), when invoked with a False argument provides the same output of .gist.

Input strings

The class accepts a named argument for its construction: version-string. Acceptable strings are those in the form:

• va.b.c
• a.b.c
• va.b
• a.b
• xbetay
• xalfay

So for example all the following are good strings: 9.6.5, 6.10, 10.1, 11beta3.

Main methods

The .parse method performs the main work disassembling the version string used to construct the object into pieces that are then stored in the class internal attributes, as numbers (Int). You can call .parse after a version object has been created to change its internal status.
The class provides several methods with easy-to-understand names:

• is-alfa, is-beta to check if the version string identifies a development branch;
• major-number, minor-number to get the single pieces of a numbering. Please note that .major-number returns a Str because for 7 to 9 numbering scheme the major number is made by two digits separated by a dot. I’m thinking about the idea of using a Rat to return a numeric value, but I’m not sure it is a good idea. Internally, however, all the data is kept as integers;
• server-version and server-version-num are there to provide the same behavior of a SHOW issued on PostgreSQL connection;
• http-download-url accepts an optional URL as base and returns the HTTP link to download the specified version of PostgreSQL.

The class also defines the ACCEPTS method that is used for smart matching, so that you can say if two objects are the same, as well as comparing if they are older or newer with respect one to the other: See the tests for a more comphrensive usage of the instances and of the methods.

I hope this can be helpful to someone, I could one day collect other utilities and release them as a whole module.