The relational operations work on sets. That's often useful, but there are situations in which preserving cardinality is more useful. One such situation bit me today -- I did some relational operations on some spreadsheet-esque data, much as I would in SQL or SPARQL, finally projecting to the two columns I cared about before adding up some numbers.
The numbers didn't total correctly. A few minutes of reading my code narrowed it down to the projection, which of course outputs a set, discarding some of my inputs. Has there been any thinking about supporting a 'bag' sibling of 'set', and allowing it to be passed correctly through the relational operators? Right now I have a choice between rephrasing my code in non- relational terms, or adding a unique value to each item to thwart the distinctness semantics. I can't help but think that other people will also encounter this. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~----------~----~----~----~------~----~------~--~---
