7 Packages and Visibility Rules

• All program units and subprograms have their name at the end:

        package P is
           ...
        end P;
  

• We will use the style of use-ing with-ed packages, with the context clauses looking like:

        with A; use A;
        with B; use B;
  

• Names declared in the visible part of packages should be unique, to prevent name clashes when the packages are used.

        package Entity is
           type Entity_Kind is ...;
           ...
        end Entity;
  

• After the file header comment, the context clause and unit specification should be the first thing in a program_unit.
• Preelaborate, Pure and Elaborate_Body pragmas should be added right after the package name, indented an extra level and using the parameterless form:

        package Preelaborate_Package is
           pragma Preelaborate;
           ...
        end Preelaborate_Package;