On Fri, Feb 2, 2018 at 9:59 PM, <matthewju...@gmail.com> wrote: > > Each path represented as a slice of coordinates could be easily encoded to > a string and compared that way. >
Ah, I misunderstood "path". > > As far as resource expenses go, we'd need benchmarks to say much. I > understand looking at expensive cases too, but that doesn't mean that there > aren't smaller regular use cases. Goroutines can be overused too. > > Matt > > On Wednesday, January 31, 2018 at 10:24:30 AM UTC-6, rog wrote: >> >> On 30 January 2018 at 23:19, <matthe...@gmail.com> wrote: >> >> - When slices can be compared, they can be used as map keys. What >> happens >> >> if the contents of a slice are changed after it has been added to a >> map? >> > >> > >> > I’m not too familiar with Go map internals, but my thought is the key >> hash >> > would depend on the backing array values. Go maps also allow reading >> the >> > keys back using iteration so the slice backing array (up to length) >> would >> > have to be copied. If the slice contents are changed then that would be >> a >> > different key and the original key would be intact. >> >> Note that copying the slice contents to make a map key implies >> that using a slice as a map key might imply copying a whole tree, >> which seems rather expensive to me (especially as it might end up >> using more memory than the original if some elements are duplicated, >> unless an alias-aware copy algorithm is used which would be >> more expensive still) >> >> BTW you can already do something like this: >> https://play.golang.org/p/q4bz8-AckN3 >> >> You can even do it without reflect, which I'll leave as an exercise >> for the reader :) >> > -- > 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. > For more options, visit https://groups.google.com/d/optout. > -- 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. For more options, visit https://groups.google.com/d/optout.
