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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: Q: type ... is new String
Date: Mon, 4 Jun 2012 11:09:43 +0200
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Date: 2012-06-04T11:09:43+02:00
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On Mon, 04 Jun 2012 10:14:55 +0200, Yannick Duch�ne (Hibou57) wrote:

> A path is intently a string is all platform I know,

RSX-11 had path of two letter device, two numbers of the directory,
RADIX-50 encoded file name, extension and numeric version. E.g.
DX:[1,54]HELLO.ADA;4. Neither part of this was ASCII string. And path
weren't stored anywhere if "internally" meant "kept on the magnetic
carrier."

> A string and a file's path belongs to the same class.

I prefer separate types for path, device, file name, for absolute and
relative paths.

A common class with strings may be present per conversions between strings
and paths. E.g. a path with non-Latin1 letters to String would raise
Constraint_Error.

However, if typed properly, you better have no implicit conversions to
strings at all. If you look into it, strings are actually used as a
middleman for rendering, I/O etc. A comprehensive design may need no such
thing. E.g. you would write paths directly to a text file and read them
from there back as you do with numbers.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de