Re: Community Input for the Maintenance and Revision of the Ada Programming Language

[Robert Eachus <rieachus@comcast.net>]

On Tuesday, August 22, 2017 at 3:34:56 AM UTC-4, Dmitry A. Kazakov wrote: 
> > What you want is a tagged type URL.
> 
> Typed with all types necessary. E.g. we need an operations to iterate 
> directory nodes etc.
> 
> > The base type could have conversions to/from string, with child types
> > like local_path, etc.,
> 
> I don't directly see how the above types should be rooted in the same 
> parent. File version has nothing to do with MIME type.

You are missing the concept.  A URL is well defined today.  But say that as quantum computers become more common, there is a form of locator which uses set notation:  "I want photographs taken September 17, 2012, near these (Lat/Long) coordinates."  URLs are extensible, and there is no reason why you shouldn't have one form for local files, and another for internet resources.

The function which converts a text string to a URL can call itself recursively, or more likely have typed calls to say the part of the function which processes file names.

Hmmm.  Another example is that long URL from HTML get accesses.  You might want to have an extension to decode your custom get queries.