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[REBOL] Re: On mutability and sameness

From: g:santilli:tiscalinet:it at: 15-Jun-2001 19:18

Hello Ladislav! I hope you don't mind me jumping in. :-) On 15-Giu-01, you wrote: LM> My POV: According to Rebol, values can be the same. If the LM> values are the same for Rebol, they are the same for me, i.e. LM> they are one value. If I use this approach, I know, that LM> Rebol values are sharable, because: LM> a: 12:30 LM> b: a LM> same? a b ; == true Sorry to disappoing you, Lad, but this seems to prove SAME? is not doing what you think it is doing:
>> a: 12:30
== 12:30
>> b: a
== 12:30
>> same? a b
== true
>> b/minute: 0
== 0
>> same? a b
== false
>> b/minute: 30
== 30
>> same? a b
== true LM> Thus, all Rebol values are sharable for me ('a and 'b are LM> sharing the same time value). It is the Observation #1 in my They are not, at least this cannot be determined using the SAME? function. LM> looked at 'b. This leads to another conclusion: SAME? lies a LM> bit, when it says we are sharing values. We are not, we have LM> copies sometimes. There is a problem: what does SAME? say LM> then? Look above. :-) LM> Now the full classification: the observed change is a LM> mutation of the word 'a, which changed (namely replaced) its LM> stored value attribute, which was an integer. (I actually think that that was a change in a context! value, not in a word! value, but well...) Regards, Gabriele. -- Gabriele Santilli <[giesse--writeme--com]> - Amigan - REBOL programmer Amiga Group Italia sez. L'Aquila --