phone_code.clj

Coder.scala

package demo
  
class Coder(words: List[String]) {

  private val mnemonics = Map(
      '2' -> "ABC", '3' -> "DEF", '4' -> "GHI", '5' -> "JKL", 
      '6' -> "MNO", '7' -> "PQRS", '8' -> "TUV", '9' -> "WXYZ")
      
  private val charCode: Map[Char, Char] = 
    for ((digit, str) <- mnemonics; letter <- str) yield letter -> digit
          
  private def wordCode(word: String): String = word.toUpperCase map charCode
    
  private val wordsForNum: Map[String, Seq[String]] = (words groupBy wordCode) withDefaultValue List()
  
  def encode(number: String): Set[List[String]] = 
    if (number.isEmpty) Set(List())
    else {
      for {
        split <- 1 to number.length
        word <- wordsForNum(number take split)
        rest <- encode(number drop split)
      } yield word :: rest
    }.toSet

  def translate(number: String): Set[String] = encode(number) map (_ mkString " ")
}

object Coder extends App {
  val dict = io.Source.fromFile("/usr/share/dict/words")
     .getLines.filter(_.length > 1).filter(_.matches("[a-zA-Z]+")).toList  
  val coder = new Coder("Scala" :: "rocks" :: dict)
  println(coder.translate("7225276257"))
}

gistfile1.clj

(use '[clojure.core.logic prelude nonrel])

(def words (string/split-lines (slurp "/usr/share/dict/words")))

(def mnemonics {\2 "ABC" \3 "DEF"  \4 "GHI" \5 "JKL"
                \6 "MNO" \7 "PQRS" \8 "TUV" \9 "WXYZ"})

(def char-code (into {} (for [[digit string] mnemonics letter string] [letter digit])))

(defn word-code [word] (map char-code (.toUpperCase word)))

(defrel wordo ^:index ns ^:index cs)

(doseq [word (filter #(<= (count %) 7) words)] (fact wordo (word-code word) word))

(fact wordo '() "")

(defn encode [s]
  (let [s (seq s)]
    (run* [q]
      (exist [x y xo yo]
        (appendo x y s) (wordo x xo) (wordo y yo)
        (project [xo yo] (== q (apply str xo yo)))))))

(comment
  (encode "6327537")
  )