There is a difference in the meanings of terms in this discussion, maybe that’s confusing to some. (That is, Ian went right to the heart of the matter but maybe a simpler fact needs to be made plain to others.)
When you think of the memory used by a slice and of maybe using less of it and “returning” the rest, like putting uneaten food away for tomorrow, you’re making several big demands. You demand severabity, that half a TV set is a reasonable thing to discuss, like half a pie. In fact that backing array was created by the allocator as “256 bytes you can use, with other info you don’t know about somewhere.” To chop off half and “give it back” is not part of the contract. The contract is: use it until you’re done with it. (The whole TV, because of wires and glass bits). One alternative is to make 256 allocations of the small parts, then allocate an array as pointers to each little part. Then you can reshape the array and free the extra parts. This freedom pays a tax in many ways, and always pays it in the normal case. But in the efficient single group allocation style (Go, C, C++, ...) the desire to return part of a monolithic allocation is a major burden. Ian went right to the elements of that burden. But since the follow ups still wanted the burden I thought maybe a reminder of why it is hard would help. On Fri, Jul 19, 2019 at 7:36 AM Ian Lance Taylor <i...@golang.org> wrote: > I'm not sure what to say. If someone wants to write up and work on a > detailed implementation proposal, that is fine. Go for it. As I said > earlier, I think it would be hard. I'll add that I don't think that > the difficulty would pay off in terms of the amount of real code that > it would help. There is a lot of other hard work that could be done > in the compiler that would, I think, help many more programs. > > Ian > > -- > You received this message because you are subscribed to the Google Groups > "golang-nuts" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to golang-nuts+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/golang-nuts/CAOyqgcVvDz1kRzpoKNtw5MDH%2BrFpsW6fLSqrT%3DS83JGhM_Y-%2BA%40mail.gmail.com > . > -- *Michael T. jonesmichael.jo...@gmail.com <michael.jo...@gmail.com>* -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/CALoEmQxJOkrYvT7yjmEFGr%2BT_xFiairSgYmUp%3Drx2EZTqVPLWw%40mail.gmail.com.
