[REBOL] Re: [Mutability bitset] Puzzle (*very hard*!)
From: lmecir:mbox:vol:cz at: 29-Sep-2006 16:26
Gregg Irwin napsal(a):
> Hi Ladislav,
>
> LM> are REBOL bitsets mutable or not?
>
> Two bitsets can refer to the same set of bits, and will return true
> for SAME?, but they aren't references to the same underlying bitset.
>
they may or may not, that is the next part of the puzzle.
> However, you can use INSERT and REMOVE to modify a bitset, so they're
> mutable in that sense.
>
checking, whether INSERT mutates bitsets:
bitset1: charset ""
bitset1-2: :bitset1
insert bitset1-2 #"a" ; == make bitset! #{
0000000000000000000000000200000000000000000000000000000000000000
}
bitset1 ; == make bitset! #{
0000000000000000000000000200000000000000000000000000000000000000
}
, i.e. the bitset was indeed mutated, not just replaced!
Congratulations, your answer was correct. So now the connected question:
*Is there a way how to discern equal bitsets that don't reference
identical
underlying bitset?*
