On Mon, Sep 28, 2020 at 08:04:49PM +0000, ikod via Digitalmars-d-learn wrote: > On Monday, 28 September 2020 at 19:18:20 UTC, H. S. Teoh wrote: [...] > > The problem with arbitrary, unrestricted modification of a container > > while iterating over it, is that it inevitably leads to > > counterintuitive results. > > Thanks for your reply, and sorry if I was not clear, but I meant AA. > AA is unordered container, so for me intuitive behavior for mutations > visibility during iteration is next: > > 1) you must not see removed keys. Let our keys are (unordered) A D C E > F, you stay on D and remove E. Then E must not be seen on any future > iteration steps. > > 2) you may or may not see any inserted keys. As AA is unordered > container there is no reason to expect anything about position of key > you just inserted - it can fall before or after current iteration > position, so implementation is free to show inserted keys or not. I > prefer not to see new keys. > > 3) you expect to visit all not removed keys exactly once. > > Is it sane? [...]
It sounds reasonable, but it does constrain your implementation. For example, (3) is likely to break during a rehash. But not rehashing may lead to other problems, depending on your hashing implementation. T -- Time flies like an arrow. Fruit flies like a banana.
