Re: Progress on AdaOS

[Steffen Huber <steffen.huber@gmx.de>]

Larry Kilgallen wrote:
> 
> In article <3B8AB6C8.910130C8@san.rr.com>, Darren New <dnew@san.rr.com> writes:
> 
> >> Then we have
> >> for example, types text, image, video, audio, program, data and
> >> text/utf8, text/utf8/crlf, text/utf8/lf, text/utf8/psls, image/png,
> >> image/tiff, image/tiff/lzw, data/word, data/word/7.0, etc.
> >
> > How about the type for Ada source files? Ada specification headers? Ada
> > bodies? The type for an "Active Server Page" with Ada code embedded in
> > HTML markup under control of CVS? And how do you determine which
> > programs can read such? :-)
> 
> You determine which programs can read it by having the programs declare
> that they can read it.

You have just described the RISC OS way of handling the problem.
Congratulations ;-)

> A user must be able to choose their "preferred"
> reader for a particular type, if there are multiple possible readers.

RISC OS does that in an interesting, and sometimes strange (for the
user) way.

RISC OS defines a "filetype" for types of file contents. This filetype
is allocated centrally and must be unique for every type of content.
There are a few things connected to the filetype like a translation
table to MimeMaps and to DOS extensions for outside communication (this
was an afterthought of course).

Every RISC OS application is "hidden" inside a special directory on
the filing system. As soon as the application is "seen" by the system
(which happens when the user opens the filer window (RISC OS equivalent
to the Windows Explorer) where the application happens to be), a batch
file inside the application (named !Boot) is executed. If the application
is able to handle a special filetype, it declares that it can handle
that filetype. If another application is "seen" by the system that
handles that filetype, the first declaration gets overwritten. So basically
the user decides by using the respective part of the filing system which
application he prefers to handle his data.

Apart from that, due to RISC OS's way of implementing drag&drop,
double clicks are not overly important.

> But there are various types of "reading" there is the "edit" type and
> the "compile" type for source files, but for object files there is
> the "link" type and the "strip out symbol data" type.

This is not handled by RISC OS in any meaningful way - well, RISC OS
was created in 1987, so you can't really expect perfection ;-)

[snip]

ObAda: there is a port of GNAT 3.03 for RISC OS...

Steffen

-- 
steffen.huber@gmx.de               steffen@huber-net.de
GCC for RISC OS  - http://www.arcsite.de/hp/gcc/
Private homepage - http://www.huber-net.de/