RosettaCodeData/Task/Execute-a-Markov-algorithm/Scala/execute-a-markov-algorithm-...

17 lines
673 B
Scala

import scala.io.Source
if (argv.size != 2 ) error("Syntax: MarkovAlgorithm inputFile inputPattern")
val rulePattern = """(.*?)\s+->\s+(\.?)(.*)""".r
val isComment = (_: String) matches "#.*|\\s*"
val rules = Source fromPath args(0) getLines () filterNot isComment map (rulePattern unapplySeq _ get) toList;
def algorithm(input: String): String = rules find (input contains _.head) match {
case Some(Seq(pattern, ".", replacement)) => input replaceFirst ("\\Q"+pattern+"\\E", replacement)
case Some(Seq(pattern, "", replacement)) => algorithm(input replaceFirst ("\\Q"+pattern+"\\E", replacement))
case None => input
}
println(argv(1))
println(algorithm(argv(1)))