02:25 <Pixel_Outlaw> Ahoy all. Is it safe to mutate a quasi-quoted list? I know you're not supposed to for standard quoted list literals.

03:36 <bike> Pixel_Outlaw: no, it is not safe.

03:37 <Pixel_Outlaw> bike, Thanks.

03:38 <Pixel_Outlaw> Really then you can say that spliced lists can't be used in the full capacity of lists made with the LIST function?

03:38 <Pixel_Outlaw> Hmm, I wonder if I've made some bad macros in the past then.

04:25 <White_Flame> technically, mutating the 3rd+ elements of `(1 2 ,@(runtime-generated-things)) should be safe, just not anything in literally specified cells

04:29 <beach> I don't see how the first and the second cell could be literally specified. The second cell must be created with its CDR generated at run time, and the first cell must have the second cell in its CDR.

04:40 <White_Flame> oh, I guess that's true

04:41 <White_Flame> basically any literal sublist would be off-limits to modification, while any concatenated non-tail portion of a list would be dynamically allocated

04:42 <White_Flame> sublist = a full list value somewhere, not a span of a larger list

04:43 <aeth> so the quoted list in this isn't literal? `(progn '(1 2 ,@(runtime-generated-things)))

04:43 <White_Flame> (dyn dyn (lit lit) ,@(...) lit lit)

04:44 <White_Flame> right

04:45 <White_Flame> a list containing a dynamically generated list element would have to be copied/appended/etc

04:46 <White_Flame> transitively

04:46 <White_Flame> however, that's just the practice of the matter. the spec is probably more conservative

04:47 <Pixel_Outlaw> So ` makes kind of a mess then.

04:50 <White_Flame> dynamic allocation is contagious within `

04:50 <White_Flame> any fully literal list however should remain literal and not be mutated

04:50 <White_Flame> unless used by ,@ ;)

04:51 <White_Flame> in a non-tail position (1 2 ,@(3 4 5) 6)

04:51 <White_Flame> so yeah, rules upon rules. Don't mutate anything ;)

04:52 <aeth> this sort of thing is best done immutably, anyway

04:53 <Pixel_Outlaw> Ok, that's fair.

04:55 <Pixel_Outlaw> So, for example if I have a list of card faces like `(A K Q J 1 2 3 4 5 6 7 8 9 10) I should not use stuff like remove-if

04:56 <Pixel_Outlaw> Sorry, delete-if