Document Metamodel::Versioning

doc/Type/Metamodel/Versioning.pod6

@@ -0,0 +1,75 @@
+=begin pod :kind<Type> :subkind<role> :category<metamodel>
+
+=TITLE role Metamodel::Versioning
+
+=SUBTITLE Metaobjects that support versioning
+
+   role Metamodel::Versioning { ... }
+
+L<Metamodel|/language/mop> role for (optionally) versioning metaobjects.
+
+When you declare a type, you can pass it a version, author, and/or API and get
+them, like so:
+
+=begin code :lang<perl6>
+class Versioned:ver<0.0.1>:auth<github:Kaiepi>:api<0> { }
+
+say Versioned.^ver;  # OUTPUT: «0.0.1␤»
+say Versioned.^auth: # OUTPUT: «github:Kaiepi␤»
+say Versioned.^api:  # OUTPUT: «0␤»
+=end code
+
+This is roughly equivalent to the following, which also sets them explicitly:
+
+=begin code :lang<perl6>
+BEGIN {
+    class Versioned { }
+    Versioned.^set_ver:  '0,0,1';
+    Versioned.^set_auth: 'github:Kaiepi';
+    Versioned.^set_api:  IntStr.new: 0, '0';
+}
+
+say Versioned.^ver;  # OUTPUT: «0.0.1␤»
+say Versioned.^auth: # OUTPUT: «github:Kaiepi␤»
+say Versioned.^api:  # OUTPUT: «0␤»
+=end code
+
+=head1 Methods
+
+=head2 method ver
+
+    method ver($obj)
+
+Returns the version of the metaobject, if any, otherwise returns L<Mu|/type/Mu>.
+
+=head2 method auth
+
+    method auth($obj)
+
+Returns the author of the metaobject, if any, otherwise returns an empty string.
+
+=head2 method api
+
+    method api($obj)
+
+Returns the API of the metaobject, if any, otherwise returns an empty string.
+
+=head2 method set_ver
+
+    method set_ver($obj, $ver)
+
+Sets the version of the metaobject.
+
+=head2 method set_auth
+
+    method set_auth($obj, $auth)
+
+Sets the author of the metaobject.
+
+=head2 method set_api
+
+    method set_api($obj, $api)
+
+Sets the API of the metaobject.
+
+=end pod