Re: Object-relational impedence

From: Yagotta B. Kidding <>
Date: Mon, 10 Mar 2008 19:47:06 +0100 (CET)
Message-ID: <Xns9A5D9684FA121vdghher_at_194.177.96.26>

Marshall <> wrote in

> On Mar 10, 5:30 am, "Yagotta B. Kidding" <> wrote:
>> Marshall <> wrote
>> > On Mar 9, 7:25 pm, "Yagotta B. Kidding" <> wrote:
>> >> Superficially, you can perform the translation, but the
>> >> assignment required to imitate the projection makes any such
>> >> language not referentially transparent. You may consider the
>> >> non-transparency a non- issue of course.
>> > Um, how so? I'm not sure I see what you mean.
>> "A language that supports the concept that ``equals can be
>> substituted for equals'' in an expresssion without changing the value
>> of the expression is said to be referentially transparent.
>> Referential transparency is violated when we include set! in our
>> computer language. This makes it tricky to determine when we can
>> simplify expressions by substituting equivalent expressions.
>> Consequently, reasoning about programs that use assignment becomes
>> drastically more difficult."
> Dude? I'm a language junkie with an interest in FP. It wasn't the
> term "referential transparency" I was having trouble with. :-)
> Rather, I don't see where the assignment comes in.

You don't ?

> Mr. Perryman's example was written in a single-assignment,
> mathematical style.

And yet you still do not see where the assignment comes in in Mr. Perryman's example. Received on Mon Mar 10 2008 - 19:47:06 CET

Original text of this message