[REBOL] Re: Sameness - a pragmatic approach.
From: g:santilli:tiscalinet:it at: 11-Feb-2003 15:41
Hi Ladislav,
On Tuesday, February 11, 2003, 1:51:35 PM, you wrote:
LM> I am not able to identify the position of V uniquely in the
LM> case you specified, but my problem is a legal problem even
LM> though it may not be uniquely solvable sometimes. The same
LM> problem occurs below:
What I meant as "not well defined" was that since you used the
sentence "the position at which the given value is" you were
implying that such position exists and is unique. If we define
such position as a position in the block where there is a value
that is identical to the value V, then clearly can have multiple
solutions, and they depend on the definition of "identical".
However this is only being picky, so no point to argue. :-)
LM> way round, then there is a trouble, that you use undefined
LM> notions and you have to give the meaning to
LM> mutations/mutability first, which may be difficult/ambiguous.
It is just a matter of definitions. I could simply start by
enumerating the types that are mutable and the ones that are
immutable, then enumerate the functions that cause a mutation in a
mutable value, and then saying that values of the immutable types
are never the same, and two values of a mutable type are the same
when they are equal before and after an arbitrary mutation of one
of them.
Regards,
Gabriele.
--
Gabriele Santilli <[g--santilli--tiscalinet--it]> -- REBOL Programmer
Amigan -- AGI L'Aquila -- REB: http://web.tiscali.it/rebol/index.r
