Thank you Ben. That answers my question. About what I expected - be defensive when in doubt.
On Monday, 3 June 2019 19:07:44 UTC+1, Ben Greenman wrote: > > You want the paragraph just above the caveat about concurrent > modification: > > > A hash table can be used as a two-valued sequence (see Sequences). The > keys > > and values of the hash table serve as elements of the sequence (i.e., > each > > element is a key and its associated value). If a mapping is added to or > > removed from the hash table during iteration, then an iteration step may > fail > > with exn:fail:contract, or the iteration may skip or duplicate keys and > > values. See also in-hash, in-hash-keys, in-hash-values, and > in-hash-pairs. > > https://docs.racket-lang.org/reference/hashtables.html > -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/bce03cf0-5283-43a5-80ef-469a5794c340%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
