Using Caché Objects - InterSystems Documentation

Packages
Class Packages
Any of these classes can be referred to using their full name (which consists of package and
classname):
Do ##class(Accounting.Invoice).Method()
Do ##class(Inventory.Item).Method()
If the package name can be determined from context (see below), then the package name can
be omitted:
Do ##class(Invoice).Method()
A package is simply a naming convention: it does not provide any fundamental capabilities
beyond how classes are named.
As with classes, a package definition exists within a Caché namespace. A package cannot
span namespaces. It will be possible, in a future version, to refer to packages in other
namespaces using subscript-level mapping.
5.2 Package Names
A package name is simply a string. It may contain “.” (period) characters but no other
punctuation. Although packages may contain “.” characters, there is no true hierarchy of
packages (the various Caché development tools do display packages as a hierarchy for convenience).
If you give a class the name “Test.Subtest.TestClass” , then this indicates that the
name of the class is “TestClass” and the name of the package is “Test.Subtest” (which is
mapped to the SQL schema “Test_TestClass” , as described below).
There are several limitations on the length and usage of package names:
• A package name (including “.” characters) is limited to 31 characters or less.
32 Using Caché Objects