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[REBOL] Re: Puzzle with FIND and SELECT

From: rotenca:telvia:it at: 10-Feb-2003 11:34

Hi, Ladislav
> I am not sure it is a "definition". How is that supposed to work? Would you > like to have a function e.g. ABSOLUTELY-SAME?
I do not know. The problem is that rebol code does not give enough reflexive information. But i know that every rebol value is in a block at a given position. Beyond its attributes, it has a block position. Literal values, for example, have never the same block position: same? "a" "a" same? 1 1 should result both false. Only if same? receive pointers to value the two values can be truly the same: y: x: [[]] same? x y same? x/1 y/1 do reduce ['same? x x] The actual implementations of same?, with some values, keep in consideration memory storage, with other values ignore it. If i am not wrong, same? keep in consideration memory storage only with mutable value and ignore it with immutable value:
>> same? [] []
== false
>> same? 1 1
== true So i think that same? gives the correct result only for mutable values. Your version of same? does not exhibit a different behaviour, because function arguments are pointers in case of mutable values and copies in case of immutable values. --- Ciao Romano