Re: explanation about an error message

[Georg Bauhaus <sb463ba@l1-hrz.uni-duisburg.de>]

Evangelista Sami <evangeli@cnam.fr> wrote:
: 
: generator.adb:4:06: unit in with clause is private child unit
: generator.adb:4:06: current unit must also have parent "Decls"
 
: file generator.adb :
: -------------------------------
: 
: with Generator.Decls; use Generator.Decls;
: with Generator.Decls.Vars; use Generator.Decls.Vars;  
: package body Generator is
:   ...
: end generator;
: -------------------------------
: 
: line 4 is "with Generator.Decls.Vars; use Generator.Decls.Vars;".
: generator.decls and generator.decls.vars are two private packages.

I've found it useful to think of children as of nested packages:

package Generator is

   procedure run;

private  -- part of Generator

   foo: Wide_Character;

   package Vars is

      var_foo: Wide_Character;


   private  -- part of Vars

      package Decls is
         decl_foo: Wide_Character;
      end Decls;

   end Vars;

end Generator;

package body Generator is

   ---------
   -- run --
   ---------

   procedure run is
      oops: Wide_Character;
   begin
      oops := Vars.var_foo;
      oops := Vars.Decls.decl_foo;
   end run;

end Generator;


    11.       oops := Vars.Decls.decl_foo;
                          |
        >>> "Decls" is not a visible entity of "Vars"