Re: Operating System differences and Ada OS independent programming

[Shark8 <onewingedshark@gmail.com>]

On Wednesday, March 23, 2016 at 2:39:08 AM UTC-6, Dmitry A. Kazakov wrote:
> 
> Ada's abstraction should reflect the most generic file system properties:
> 
> - Acyclic directed graph of names built from Unicode code points;

No, these should be a private type which is 0..Unsigned_32/64 and has the name as a property whose value is a unicode string. There should be a "translate" function which takes a Unicode string and translates it into the filesystem-actual's encoding. -- an identical yet distinct type should exist for directories.

> - Multiple roots (AKA devices);

No, absolutely not.
These should NOT be part of the filesystem; instead there should be a Physical_Drive type and a Virtual_Drive type, where the former denotes a physical drive, and the virtual denotes either a single partition of a physical_drive or multiple physical drives. (VMS has the capibility to view multiple HDs as a single logical drive.)

UNIX caused all sorts of trouble with their misguided "everything's a file" stupidity.

> - Absolute vs. relative path distinction;

Yes.

> - Current directory path generator;

Pretty much unneeded if there's a directory-type:
Type FS_Rider is
  Current : Directory_Type;
  -- Other state information.
end record;

> - Generators for special directory paths (home, my downloads, my 
> documents etc);

These could be a simple map (key -> directory_type), populated as needed by the particular OS/FS.

> - Extension / MIME types;

Why?

> - Version / change / release number;

Definitely.

> - Time stamps (modification, creation etc).

Which should be Ada.Calendar.Time.