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davin.church	Two ideas from A+ Posted: Thursday, July 22, 2004 12:26 PM (EST) I (and probably many others) use a similar structure quite frequently, but it's a vector of nested name/value pairs (e.g.  ('a' 4) ('b' 17) ('c' 'who')).  I also have an alternate form where it's a two-column matrix.   I like the idea of pick taking a character left argument, but it probably doesn't fit into the theoretical language design very well.  But until then, we can use a trivial function to pick out those values for us (though updating them is less clean).
Michael.Hughes	Two ideas from A+ Posted: Thursday, July 22, 2004 3:59 PM (EST) Well, the way the char left arg of pick would work is to use selective assignment   (ie)    ('aaa'{pick}data) {gets} newvalues   I also use a trivial function but I think this is much neater (and more efficient) to use {pick}.  Once easy and effiicient to use its amazing how useful the structure is.  The advantage of using the two element data structure is that the 1st pick gives you the list of fields so its easy to get a list of valid field names. In the case proposed to check whether a data item exists is (enclose name) {member} 1 {pick} data to append is simply data {gets}data {catenate} {each} {enclose}{each}( name newdata) or data {gets} data {catenate}{each} (newdata of same structure) merge is a little more interesting but can be achieved using 1 {pick}