Hi Hatthew, I am still trying to implement 'case' by means of a hash. Can you give me a more specific pointer. I followed your pointer but did not see anything relevant to my question. Jos
-----Original Message----- From: Matthew Flatt [mailto:mfl...@cs.utah.edu] Sent: miércoles, 28 de septiembre de 2011 22:20 To: Jos Koot Cc: 'Racket-users' Subject: Re: [racket] case form implemented with a hash At Wed, 28 Sep 2011 22:08:44 +0200, "Jos Koot" wrote: > By inspection with the macro stepper I found that case forms are expanded to > nested if-forms. For case forms with many clauses, this may be inefficient. > I have tried to prepare a hash-case form using a hash table in order to > select the desired clause more efficiently. So far my attempts failed. I am > still trying. However, has anybody else on this list thought of using a hash > for case forms with many clauses? Does it exist? If not, would anyone be > interested in a hash-case form that has the same shape as a case-form, but > uses a hash-table to select the appropriate clause? The hash table should be > a map onto thunks and macro hash-case simply would have to retrieve the > thunk and call it. See "Rapid Case Dispatch in Scheme", Clinger, Scheme'06. If you implement a revised `case' that consistently works better, then I'd be happy to use it as a replacement for the current `case'. _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
