CODEWITHSUNDEEP
clojurefunctional-programming
Gilad
Gilad

Reputation: 6595

Clojure AND / OR of Sets

(defn GetValuesFromWhereCommand
    "return a list of values from Where command"
    [Query tableName]
    (let [values (re-seq #"[0-9a-zA-Z_=<>]+" ((re-find #"WHERE(.*)" Query) 1))
        bitwise (re-find #"AND|OR" Query)
        tempList (ref #{})
       ] 
   ; first loop will look for the operators  = < >
   (doseq [item values]
    (let [result (case (re-find #"[=><]" item)
        "=" (GetRowsfromCondition tableName item = )
        "<" (GetRowsfromCondition tableName item < )
        ">" (GetRowsfromCondition tableName item > )
        nil (println "nothing")
     )]
     (when (not= nil result) (dosync (alter tempList conj result)) )
    tempList)
   )
   (println tempList)
   tempList)     ; get the Where from Update ','
)

here is my output.

#<Ref@5a4e229e: #{#<Ref@3fc2e163: #{0}> #<Ref@63280c85: #{0 1}>}>

i would like to make implement AND operation that will return #{0}
and OR that will return #{0 1}.


my problem is how to access the lists i have created. I wasn't able to use union/intersection for some reason.

Upvotes: 1

Views: 64

Answers (1)

sstanmel
sstanmel

Reputation: 81

You should deref all the inner sets and apply union to the new set it should look somthing like this:

(let [newList (ref #{})] (doseq [item @your_ref_to_set_of_refs] (dosync (alter newList conj @item))) (apply union @newList))

Upvotes: 3

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