tasks a-s

Task/Execute-a-Markov-algorithm/Scala/execute-a-markov-algorithm-1.scala

@@ -0,0 +1,30 @@
+import scala.io.Source
+
+object MarkovAlgorithm {
+  val RulePattern = """(.*?)\s+->\s+(\.?)(.*)""".r
+  val CommentPattern = """#.*|\s*""".r
+
+  def rule(line: String) = line match {
+    case CommentPattern() => None
+    case RulePattern(pattern, terminal, replacement) => Some(pattern, replacement, terminal == ".")
+    case _ => error("Syntax error on line "+line)
+  }
+
+  def main(args: Array[String]) {
+    if (args.size != 2 ) {
+      println("Syntax: MarkovAlgorithm inputFile inputPattern")
+      exit(1)
+    }
+
+    val rules = (Source fromPath args(0) getLines () map rule).toList.flatten
+
+    def algorithm(input: String): String = rules find (input contains _._1) match {
+      case Some((pattern, replacement, true)) => input replaceFirst ("\\Q"+pattern+"\\E", replacement)
+      case Some((pattern, replacement, false)) => algorithm(input replaceFirst ("\\Q"+pattern+"\\E", replacement))
+      case None => input
+    }
+
+    println(args(1))
+    println(algorithm(args(1)))
+  }
+}

Task/Execute-a-Markov-algorithm/Scala/execute-a-markov-algorithm-2.scala

@@ -0,0 +1,16 @@
+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)))