CL's defparameter corresponds to plain def. There is a level of structure you are not representing: alternatives.
Here is what I'd use: :sentence [[:noun-phrase :verb-phrase]] ... :article ["the" "a"] ... The string literals are the implicit terminals and are thus easy to distinguish. An article isn't a terminal since it has multiple alternatives. -Per On Wed, Mar 10, 2010 at 12:47 PM, Mike K <[email protected]> wrote: > In PAIP section 2.3, Norvig gives an example of a generative grammar: > > ;; common lisp > (defparameter *simple-grammar* > '((sentence -> (noun-phrase verb-phrase)) > (noun-phrase -> (Article Noun)) > (verb-phrase -> (Verb noun-phrase)) > (Article -> the a) > (Noun -> man ball woman table) > (Verb -> hit took saw liked)) > "A grammar for a trivial subset of English.") > > What's the most idiomatic way to write something like this in > Clojure? My first attempt is as follows: > > > (defonce- *simple-grammar* > {:sentence [:noun-phrase :verb-phrase] > :noun-phrase [:Article :Noun] > :verb-phrase [:Verb :noun-phrase] > :Article '(the a) > :Noun '(man ball woman table) > :Verb '(hit took saw liked)} > "A grammar for a trivial subset of English.") > > Assume I'm going to need some way to distinguish terminals from non- > terminals. Above I used lists vs vectors. If this were a non-toy app > where I was optimizing for performance, would it make more sense to > use vectors everywhere? If so, what would be a good succinct way to > differentiate the two rule types? Could I add meta-data to the vector > literals somehow? Or perhaps use structs instead? > > Thanks, > Mike > > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to [email protected] > Note that posts from new members are moderated - please be patient with your > first post. > To unsubscribe from this group, send email to > [email protected] > For more options, visit this group at > http://groups.google.com/group/clojure?hl=en -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to [email protected] Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/clojure?hl=en
