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From: edm@vrdxhq.verdix.com (Ed Matthews)
Newsgroups: comp.lang.ada
Subject: Optional Sequence of Statements Before Exception Handlers
Keywords: exception handling
Message-ID: <34741@vrdxhq.verdix.com>
Date: 29 Jun 90 14:15:38 GMT
Organization: Verdix Corporation, Chantilly,  VA
List-Id: <comp.lang.ada>

I've been thinking about the following situation recently:

  exception
    when foo_error =>
      A;
      B;
    when bar_error =>
      A;
      B;
      C;
    when others =>
      A;
      B;
      D;
  end;

and wondering if allowing the following would be a "good thing:"

  exception
    A;
    B;  -- these two statements comprise the optional sequence before handlers
    when foo_error =>
      null;
    when bar_error =>
      C;
    when others =>
      D;
  end;

This obviously poses some awkward spots -- like the null; statement with
non-null semantics and if an exception occurs in the optional sequence
of statement, where/how/in which scope it can be handled.  

Of course, we can always write a procedure encapsulating A; B; and call it
from each of the handlers.  Then we get into the wouldn't it be nice if
we could pass parameters to handlers and access the name of the exception
(or an enumeration literal representing the exception) in a standard manner.

Anybody know what the current thinking about exception handling is with
respect to 9X?
-- 

Ed Matthews                                                edm@verdix.com
Verdix Corporation Headquarters                            (703) 378-7600
Chantilly, Virginia