From: shang@corp.mot.com (David L. Shang)
Subject: Re: Eiffel and Java
Date: 1996/10/31
Date: 1996-10-31T00:00:00+00:00 [thread overview]
Message-ID: <1996Oct31.162218.8386@schbbs.mot.com> (raw)
In-Reply-To: 55562c$nkd@mulga.cs.mu.OZ.AU
In article <55562c$nkd@mulga.cs.mu.OZ.AU> fjh@mundook.cs.mu.OZ.AU (Fergus
Henderson) writes:
> Suppose I have two existing library classes (perhaps supplied by different
> vendors) which have some commonality, but don't inherit from a common
> base class. In Sather, one can simply create a new interface and
> declare these classes to be instances of this interface, without
> modifying the existing code.
>
> (Is that possible in Java?)
>
No. Java supports only top-down class hierarchy construction
(from superclass to subclasses), but not bottom-up: from
subclasses to superclass.
But Sather's superclass construction is limited to non-parametrerized
classes only.
Transframe provides a more powerful superclass construction that
can support parameterized classes.
Suppose we have two existing classes
class Stack #(MemberType: type of any)
{
function push(MemberType);
function pop:MemberType;
}
class Queue #(MemberType: type of any)
{
function push(MemberType);
function pop:MemberType;
}
and later, we decide to have a superclass from them, we can have
class StackOrQueue #(MemberType: type of any)
is super Stack, Queue
{
function push(MemberType);
function pop:MemberType;
}
without modifying the existing subclasses.
Now, we can write polymophic code like:
x: StackOrQueue;
if (some_condition) x = Stack#(T1)(); else x:=Queue#(T2)();
y: any = GetObject();
assume (y is x#.MemberType) x.push(y); otherwise do_nothing();
We can do the push without knowing whether "x" is a queue or
a stack; we don't know the exact member type either,
the type assurance statement will guarantee that the program
free of run-time type exceptions.
David Shang
next prev parent reply other threads:[~1996-10-31 0:00 UTC|newest]
Thread overview: 168+ messages / expand[flat|nested] mbox.gz Atom feed top
1996-10-27 0:00 Eiffel and Java Vincent WEBER
1996-10-27 0:00 ` Jean-Michel P. Decombe
1996-10-28 0:00 ` Robert Dewar
1996-10-31 0:00 ` Doug Marker
1996-10-28 0:00 ` Alexandre Oliva
1996-10-28 0:00 ` David Hanley
1996-10-28 0:00 ` Matt Kennel
1996-10-29 0:00 ` Chris Trimble
1996-10-31 0:00 ` Doug Marker
1996-10-31 0:00 ` David Bennett
1996-10-28 0:00 ` Larry Kilgallen
1996-10-30 0:00 ` Ronald Cole
1996-10-28 0:00 ` Matthew Heaney
1996-10-29 0:00 ` Vincent WEBER
1996-10-31 0:00 ` James McKim
1996-11-01 0:00 ` Matthew Heaney
1996-11-04 0:00 ` James McKim
1996-10-30 0:00 ` Jon S Anthony
1996-11-01 0:00 ` Eiffel and Java + Ada dispatching Jean-Marc Jezequel
1996-10-30 0:00 ` Eiffel and Java Don Harrison
1996-10-31 0:00 ` James McKim
1996-11-04 0:00 ` Don Harrison
1996-11-23 0:00 ` Van Snyder
1996-10-31 0:00 ` Joachim Durchholz
1996-11-01 0:00 ` Norman H. Cohen
1996-11-02 0:00 ` Eiffel and Java + Ada dispatching Jon S Anthony
1996-11-02 0:00 ` Eiffel and Java Jon S Anthony
1996-11-03 0:00 ` Joachim Durchholz
1996-11-05 0:00 ` Norman H. Cohen
1996-10-29 0:00 ` Don Harrison
1996-10-29 0:00 ` Eiffel and Java + Ada dispatching Vincent WEBER
1996-10-30 0:00 ` Jean-Marc Jezequel
1996-11-01 0:00 ` Joachim Durchholz
1996-11-01 0:00 ` Don Harrison
1996-10-30 0:00 ` Don Harrison
1996-10-30 0:00 ` Jon S Anthony
1996-10-29 0:00 ` Eiffel and Java Fergus Henderson
1996-10-30 0:00 ` Don Harrison
1996-10-30 0:00 ` Fergus Henderson
1996-10-31 0:00 ` David L. Shang [this message]
1996-11-01 0:00 ` Matt Kennel
1996-11-04 0:00 ` David L. Shang
1996-11-05 0:00 ` Matt Kennel
1996-11-06 0:00 ` David L. Shang
1996-11-04 0:00 ` Robert I. Eachus
1996-11-01 0:00 ` Jon S Anthony
1996-11-02 0:00 ` Fergus Henderson
1996-11-04 0:00 ` David L. Shang
1996-11-05 0:00 ` Jon S Anthony
1996-11-02 0:00 ` Darko BUDOR
1996-11-02 0:00 ` Fergus Henderson
1996-11-03 0:00 ` Darko BUDOR
1996-11-03 0:00 ` Matt Kennel
1996-11-03 0:00 ` Matthias Ernst
1996-11-03 0:00 ` Jon S Anthony
1996-11-05 0:00 ` Jon S Anthony
1996-11-10 0:00 ` Marcos F. F. de Macedo
1996-11-11 0:00 ` David L. Shang
1996-11-12 0:00 ` Fergus Henderson
1996-11-12 0:00 ` David L. Shang
1996-11-12 0:00 ` David L. Shang
1996-11-16 0:00 ` Fergus Henderson
1996-11-18 0:00 ` David L. Shang
1996-11-18 0:00 ` Kai Quale
1996-11-18 0:00 ` David L. Shang
1996-11-25 0:00 ` Kai Quale
1996-11-15 0:00 ` Paul Johnson
1996-11-12 0:00 ` Alexander Asteroth
1996-11-11 0:00 ` Marcos F. F. de Macedo
1996-11-12 0:00 ` Matt Kennel
1996-11-12 0:00 ` Benedict A. Gomes
1996-10-30 0:00 ` Eiffel and Java + Ada dispatching Robert I. Eachus
1996-10-30 0:00 ` Jon S Anthony
1996-11-04 0:00 ` Don Harrison
1996-11-04 0:00 ` C to Ada Ali Mirhosseini
1996-11-04 0:00 ` Robert Dewar
1996-11-04 0:00 ` Matthew Daniel
1996-11-05 0:00 ` Eiffel and Java + Ada dispatching Jon S Anthony
1996-11-05 0:00 ` Don Harrison
1996-11-06 0:00 ` Jon S Anthony
1996-10-30 0:00 ` Eiffel and Java David Petrie Stoutamire
1996-10-31 0:00 ` Eiffel and Java + Ada dispatching Jon S Anthony
[not found] ` <E06F2B.Az7@syd.csa.com.au>
1996-11-01 0:00 ` Jon S Anthony
1996-11-04 0:00 ` Don Harrison
1996-11-05 0:00 ` Jon S Anthony
1996-11-02 0:00 ` Robert Dewar
1996-11-04 0:00 ` Norman H. Cohen
1996-11-05 0:00 ` Don Harrison
1996-11-05 0:00 ` Robb Nebbe
1996-11-06 0:00 ` Jean-Marc Jezequel
1996-11-07 0:00 ` Robb Nebbe
1996-11-06 0:00 ` To overload or not to overload (was Eiffel and Java + Ada dispatching) Don Harrison
1996-11-06 0:00 ` Robb Nebbe
1996-11-07 0:00 ` Don Harrison
1996-11-07 0:00 ` Juergen Schlegelmilch
1996-11-08 0:00 ` Don Harrison
1996-11-08 0:00 ` Don Harrison
1996-11-14 0:00 ` Jon S Anthony
1996-11-14 0:00 ` Jon S Anthony
1996-11-07 0:00 ` Jon S Anthony
1996-11-07 0:00 ` Jon S Anthony
1996-11-11 0:00 ` Don Harrison
1996-11-08 0:00 ` bill.williams
1996-11-11 0:00 ` Don Harrison
1996-11-07 0:00 ` Norman H. Cohen
1996-11-08 0:00 ` Eiffel and Java + Ada dispatching Robert I. Eachus
1996-11-05 0:00 ` Joachim Durchholz
1996-11-06 0:00 ` Robert I. Eachus
1996-11-08 0:00 ` Don Harrison
1996-11-08 0:00 ` Jon S Anthony
1996-11-08 0:00 ` Robert A Duff
1996-11-12 0:00 ` Don Harrison
1996-11-12 0:00 ` Joachim Durchholz
1996-11-15 0:00 ` Richard Riehle
1996-11-16 0:00 ` Interfacing contracts (Was: Eiffel and Java + Ada dispatching) Geert Bosch
1996-11-17 0:00 ` Robert A Duff
1996-11-12 0:00 ` Eiffel and Java + Ada dispatching Robert A Duff
1996-11-13 0:00 ` Don Harrison
1996-11-13 0:00 ` Jon S Anthony
1996-11-15 0:00 ` Don Harrison
1996-11-19 0:00 ` Jon S Anthony
1996-11-20 0:00 ` Don Harrison
1996-11-13 0:00 ` Robert A Duff
1996-11-14 0:00 ` Don Harrison
1996-11-14 0:00 ` Robert I. Eachus
1996-11-14 0:00 ` Robert A Duff
1996-11-15 0:00 ` Don Harrison
1996-11-15 0:00 ` Robert I. Eachus
1996-11-19 0:00 ` Don Harrison
1996-11-18 0:00 ` Vincent Celier
1996-11-22 0:00 ` Don Harrison
1996-11-19 0:00 ` Jon S Anthony
1996-11-15 0:00 ` portmanteau (was Re: Eiffel and Java + Ada dispatching) Robert I. Eachus
1996-11-07 0:00 ` Eiffel and Java + Ada dispatching Jon S Anthony
1996-11-07 0:00 ` Robb Nebbe
1996-11-12 0:00 ` Jon S Anthony
1996-11-01 0:00 ` Jean-Marc Jezequel
1996-10-31 0:00 ` Joachim Durchholz
1996-11-01 0:00 ` Eiffel and Java Matthias Ernst
1996-11-01 0:00 ` William Clodius
1996-11-01 0:00 ` Benedict A. Gomes
1996-11-02 0:00 ` Eiffel and Java + Ada dispatching Jon S Anthony
1996-11-02 0:00 ` Jon S Anthony
1996-11-04 0:00 ` Eiffel and Java Robert I. Eachus
1996-10-30 0:00 ` Jon S Anthony
1996-11-01 0:00 ` Don Harrison
1996-11-01 0:00 ` Jon S Anthony
1996-11-07 0:00 ` Marcos F. F. de Macedo
1996-11-11 0:00 ` Ian Joyner
1996-11-12 0:00 ` Don Harrison
1996-11-13 0:00 ` Norman H. Cohen
1996-11-15 0:00 ` Don Harrison
1996-11-14 0:00 ` Jon S Anthony
1996-11-15 0:00 ` Don Harrison
1996-11-19 0:00 ` Jon S Anthony
1996-11-21 0:00 ` Don Harrison
1996-11-12 0:00 ` Jon S Anthony
1996-10-31 0:00 ` Joachim Durchholz
1996-11-01 0:00 ` Jon S Anthony
1996-11-02 0:00 ` Jon S Anthony
1996-11-03 0:00 ` Eiffel and Java + Ada dispatching Joachim Durchholz
1996-11-04 0:00 ` Eiffel and Java Richard A. O'Keefe
-- strict thread matches above, loose matches on Subject: below --
1996-10-28 0:00 cosc19z5@bayou.uh.edu
[not found] ` <01bbc7f6$b1c0b7a0$LocalHost@gaijin>
1996-11-01 0:00 ` Alan Lovejoy
1996-11-01 0:00 ` Chris
1996-11-01 0:00 ` Ranjan Bagchi
1996-11-02 0:00 Ell
1996-11-02 0:00 ` traymond
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