Data commit

Task/String-interpolation-included-/Scala/string-interpolation-included-.scala

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+object StringInterpolation extends App {
+
+  import util.matching.Regex._
+  val size = "little"
+
+  { // Method I (preferred)
+    // Scala 2.10.0 supports direct string interpolation
+    // by putting "s" at the beginning of the string.
+    println("V2.10+  : " + s"Mary had a $size lamb,")
+  }
+
+  { // Method II
+    // Pre Scala 2.10 indirect use of Java Class Formatter
+    val originalFormatter = "Mary had a %s lamb,"
+    println("V2.10- 1: " + originalFormatter format size)
+    // Above mentioned is Scala's postfix notation and equivalent for:
+    println("V2.10- 2: " + originalFormatter.format(size))
+    // Also possible
+    printf(("V2.10- 3: " + originalFormatter + '\n').format(size))
+    // All will be expanded to
+    print(("V2.10- 3: " + originalFormatter + '\n').format(size))
+    print((new java.util.Formatter).format("V2.10- 4: " + originalFormatter + '\n', size))
+  }
+
+  { // Method III
+    // Regular expressions, only for demonstration
+    val extractor = """\$\{([^}]+)\}""".r
+    println((extractor.replaceAllIn("Regex  1: Mary had a ${x} lamb,", "snow white")))
+
+    // RegEx freaking
+    def interpolate(text: String, vars: (String, String)*) =
+      extractor.replaceAllIn(text,
+        _ match { case Groups(v) => vars.toMap.getOrElse(v, "" /*in case nothing provided*/ ) })
+
+    println(interpolate("Regex  2: ${who} had a ${size} ${pet}, ${unknown}",
+      ("pet", "lamb"), ("size", "fat"), ("size", "humongous"), ("who", "Mary")))
+  }
+
+  { // Method IV, not recommended.
+    // Standard API method, search argument (1st ones) supposed to be a regular expression
+    println("Replace1: " + "Mary had a ${x} lamb".replaceAll("""\$\{x\}""", size))
+    // Standard API method, literally, on regular expression
+    println("Replace2: " + "Mary had a ${x} lamb".replaceAllLiterally("${x}", size))
+  }
+
+  { // Method IV, not recommended.
+    println("Split   : " + "Mary had a ${x} lamb.".split("""\$\{([^}]+)\}""").mkString(size))
+  }
+}