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[REBOL] Re: On mutability and sameness

From: agem:crosswinds at: 18-Jun-2001 3:52

RE: [REBOL] Re: On mutability and sameness [kenneth--nwinet--com] wrote:
> Joel, I'm being dense again. > > When you say the integers are immutable in Rebol (implying they may be > mutable in other languages?); I'm seeing a distinction without a difference. > > You referred to mutating verses replacing. > > > a: 42 > > a: a + 1 ;=43 > > Could I not see this as an example of mutating the rightmost bit? > ...or perhaps... > Are you saying a new symbol 'a' is created in a table so that the place > where 42 is stored is unrelated to the place where 43 is stored? > ...or... > The truth is out there (but unlike the x-files I'm about to be enlightened! > ;-)) > > > Mutable: capable of being changed; read/write > > Immutable: incapable of being changed; read-only >
hm. "particle physics"? Mutable: the original value is "slow" and can be modified. Immutable: if you touch the value, it immediate "flips out", is automatic copied before. no chance to be fast enough for a change ;-) You see, very simple types are very flippy, a bit more complex types are somewhat slower and heavy series are really mutable slow. prove: a: 42 a: a + 1 ; touch a, 42 flips out, add 1, then assign the value to a, changed, hehe but a: 23:55 a/1: 56 ;touch 23:55, 23:55 yawns, 23:55 is changed. without explicit assignment and a: 1-Apr-2001/23:55 a/time/minute: 56 ; to slow, 23:55 flips out, a unchanged a/time: 23:56 ;fast enough :) so we should replace 'Immutable with 'flippy? ;-) -Volker