Re: NYU ADA QUESTION!!!

[ddciiny!jls@uunet.uu.net (Jonathan Schilling)]

In article <memo.133371@cix.compulink.co.uk> sjwright@cix.compulink.co.uk write
s:
>
>References: <1993Apr11.050845.26102@penny.cs.fredonia.edu>
>X-Newsreader: TIN [version 1.1 PL6]
>
>Kevin V. Sobilo (sobi0268@mary.cs.fredonia.edu) wrote:
>> 
>>  I am trying to use NYU Ada for a project to create a set of 
>> facilities or packages to allow TCP/IP programming in Ada.  We wish
>> to provide some nice facilities to program concurrent network
>> applications etc... Well, NYU Ada (adaed) doesnt seem to implement
>> UNCHECKED_CONVERSION or SYSTEM packages.... Can anyone tell me if
>> this is true???? 
>
>The source of System, Text_Io, ... is in the file src/predef.ada.
>Unfortunately the text of Unchecked_Conversion is ..
>
>generic
>   type SOURCE is limited private;
>   type TARGET is limited private;
>function UNCHECKED_CONVERSION(S : SOURCE) return TARGET;
>function UNCHECKED_CONVERSION(S : SOURCE) return TARGET is
>NOT_USED_ANYWAY: TARGET;
>begin
>   raise PROGRAM_ERROR;
>   return NOT_USED_ANYWAY;
>end;
>
>.. so I guess there's some work to do there. Obviously the body needs to
>be implemented in the host language :-)

DDC-I's Ada compilers implement UNCHECKED_CONVERSION "by magic" inside the
compiler; the actual library unit is a dummy that isn't really used.  I don't
know the details of the NYU Ada compiler, but it may work the same, the
"NOT_USED_ANYWAY" variable name would seem to suggest so.

-- 
Jonathan Schilling
DDC-I, Inc.
uunet!ddciiny!jls