On Mon, 31 Jan 2022, Henry Rich wrote:
The deficiency in J is that m&i. gives you a hashtable for searching m, but if you modify m you have to recalculate the hash from scratch. This makes m&i. a good read-mostly Dictionary but slow for frequent updates.
Why not cache the hash table for x when computing x i. y, and update it in-place when x is updated in-place? That should provide ideal performance without requiring any changes to language semantics.
-E ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
