Re: Help with Exceptions!

[jsa@organon.com (Jon S Anthony)]

In article <4mt0um$dgu@hearst.cac.psu.edu> RLS@psu.edu    (Robert L. Spooner, AD3K) writes:


> Another way to reexecute a statement is to have the function call
> itself from the exception handler, after outputting an error
> message.  Once the user enters valid input, the function
> willrecursively return with the proper value.  For user input from a
> keyboard, any performance differences between the loop and the
> recursive function call will be negligible.

This is a nice trick which allows you to approximate Eiffel style
exception capabilities.

> function Response (Prompt : String) return integer is
> 
>    line : ...
>    Size : ...
> 
> begin
>    Put (Prompt);
>    Get_Line (...;
>    return ...
> exception
>    when others =>
>       Put_Line (...;  -- error message
>       return Response(Prompt);
> end Response;


/Jon
-- 
Jon Anthony
Organon Motives, Inc.
1 Williston Road, Suite 4
Belmont, MA 02178

617.484.3383
jsa@organon.com