On Jun 13, 2011, at 21:18 , Daniel Weinreb wrote: > Friends, > > I wrote a little package for "fash hash tables", which provide an > abstraction that is analogous to that of Common Lisp hash tables, but > is faster for tables with few elements, and only slightly inferior for > tables with many elements. > > I did this because performance analysis showed that our system was > spending too much time in hash table operations, and using the new > package helped. > > I have recently been cleaning this up, one reason being that I'd like > to open source it. The function names used to be things like getfhash > and mapfhash. Now they are like fhash:get and fhash:map-elements and > so on. > > However, before I open-source it, I was to make sure it's "right". It > recently occurred to me that the package name "fhash" has problems. > > Here are pros and cons of changing it that I can see. > > Pro: I's not a hash table in the small-cardinality case; it's a linear > lookup. So the name is not actually accurate. > > Pro: Calling such a data structure a "hash table", even as Common Lisp > does, is an abstraction violation. Whether it works by hashing is an > implementation detail. The Java collection library calls this a Map. > Python calls it a dictionary. Clojure calls it a map. Those are both > better names.
Actually, in Java the naming reflects the separation between abstraction and implementation. AFAIU, clojure does not quite do this and neither does Python. I would advocate settling down on a Java-esque nomenclature with MAP or DICTIONARY as "names" for the abstraction and with different names for the implementations; e.g., DICTIONARY-TREE, DICTIONARY-FHASH, DICTIONARY-HASH-TABLE, you name it.... Cheers -- MA -- Marco Antoniotti, Associate Professor tel. +39 - 02 64 48 79 01 DISCo, Università Milano Bicocca U14 2043 http://bimib.disco.unimib.it Viale Sarca 336 I-20126 Milan (MI) ITALY Please note that I am not checking my Spam-box anymore. Please do not forward this email without asking me first. _______________________________________________ pro mailing list pro@common-lisp.net http://lists.common-lisp.net/cgi-bin/mailman/listinfo/pro
