Re: RE: rename missing in Text_IO

[tmoran@acm.org]

>"Ted Dennison" <dennison@telepath.com> wrote in message
>news:BrBJ6.4787$vg1.374667@www.newsranger.com...
>> My current favorite trick is to just raise a single "Foo.Error" exception
>for
>> any C error condition in each package. There are obviously some situations
>where
>> this would be undesirable, but you'd be suprised how often its sufficient.
>> Sometimes when extra info might be in order for diagnosis, it can just be
>put
>> into the execption message.
>>
>It might work nicely enough to get the job done. If a function was provided
>to return a more detailed error code (the actual return status of the C
>function?) that might be enough to get the job done cleanly.
  In Claw we have a very few exceptions, Already_Valid_Error for
instance, plus
    Windows_Error : Exception;  -- An (unusual) error occurred in Windows.
                                -- The exception message for this exception
                                -- always includes the Windows error code.
But in Claw.Sockets, for instance, the windows error code is often
uninteresting, so there is a specific
  procedure Get_Error_Code(Socket     : in out Root_Socket_Type;
                           Error_Code :    out Error_Codes);
  -- Call this after a Windows_Error exception on an operation on Socket.
to get the winsock error code.


>Maybe an example or two would suffice as a guideline? "Make it look like
>this!"
  I'll modestly suggest perusing the Claw docs, an early, incomplete,
but still showing a flavor, work version of which is still posted at
http://members.home.net/twmoran/H1.htm

>Where do you want to draw the line and say "This far and no farther?"
  Perhaps Claw defines what's beyond the line?