From: billwolf@hubcap.clemson.edu (William Thomas Wolfe,2847,)
Subject: Re: Procedure types and dynamic binding
Date: 10 Jan 89 19:11:04 GMT [thread overview]
Message-ID: <4058@hubcap.UUCP> (raw)
In-Reply-To: 5806@medusa.cs.purdue.edu
From article <5806@medusa.cs.purdue.edu>, by rjh@cs.purdue.EDU (Bob Hathaway):
>
> Another more direct way to parameterize a change operation is
> to use a procedural variable as a parameter. Such as:
>
> generic
> type ELEMENT_TYPE is private;
> package ...
> type PRINT_PROCEDURE is procedure (ELEMENT : in ELEMENT_TYPE);
> procedure CHANGE_PRINT_OPERATION (PRINT_OPERATION : in PRINT_PROCEDURE);
>
> This allows dynamic specification of statically checked print procedures per
> instance while the previous example assumed the user knew all allowable
> procedures during instantiation.
But now we have a highly changeable system. What I am asking is,
"Is there any reason we need this extremely high level of changeability?"
We are essentially getting into the realm of programs which modify
themselves, and I tend to think that this power requires extraordinary
regulation due to the ease with which such a program could modify itself
to the point that nobody can figure out how it got there in less than
omega (Ackermann's function) time, much less how to fix it.
I've suggested earlier that programs should theoretically be able to
edit source files, cause a recompilation, dump their local knowledge
into a transition file, invoke the successor on the local knowledge,
and finally commit suicide, but that this should be done with extreme
caution.
Is there any reason why we need procedural variables in addition to this?
Bill Wolfe
wtwolfe@hubcap.clemson.edu
next prev parent reply other threads:[~1989-01-10 19:11 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
1988-12-30 21:42 Procedure types and dynamic binding Erland Sommarskog
1988-12-31 17:46 ` Bob Hathaway
1989-01-05 10:02 ` William Thomas Wolfe,2847,
1989-01-07 18:05 ` Bob Hathaway
1989-01-07 21:21 ` William Thomas Wolfe,2847,
1989-01-08 1:49 ` Bob Hathaway
1989-01-08 19:01 ` William Thomas Wolfe,2847,
1989-01-08 23:10 ` Bob Hathaway
1989-01-09 1:47 ` William Thomas Wolfe,2847,
1989-01-09 20:19 ` Bob Hathaway
1989-01-10 3:01 ` William Thomas Wolfe,2847,
1989-01-10 3:06 ` Bob Hathaway
1989-01-10 19:11 ` William Thomas Wolfe,2847, [this message]
1989-01-11 2:08 ` Bob Hathaway
1989-01-11 14:24 ` William Thomas Wolfe,2847,
1989-01-11 17:51 ` Barry Margolin
1989-01-11 22:54 ` William Thomas Wolfe,2847,
1989-01-12 13:57 ` Robert Firth
1989-01-12 19:09 ` William Thomas Wolfe,2847,
1989-01-14 0:46 ` Scott Moody
1989-01-15 18:28 ` William Thomas Wolfe,2847,
1989-01-24 4:07 ` Paul Stachour
1989-01-12 0:58 ` William Thomas Wolfe,2847,
1989-01-12 6:12 ` Barry Margolin
1989-01-11 14:48 ` Submitting Ada 9X revision requests William Thomas Wolfe,2847,
1989-01-11 2:10 ` Procedure types and dynamic binding Bob Hathaway
1989-01-05 7:38 ` William Thomas Wolfe,2847,
-- strict thread matches above, loose matches on Subject: below --
1989-01-06 23:04 Erland Sommarskog
1989-01-07 22:20 ` William Thomas Wolfe,2847,
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