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Diffstat (limited to 'library/src')
-rw-r--r-- | library/src/dotty/Show.scala | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/library/src/dotty/Show.scala b/library/src/dotty/Show.scala new file mode 100644 index 000000000..123fffdc7 --- /dev/null +++ b/library/src/dotty/Show.scala @@ -0,0 +1,88 @@ +package dotty + +import scala.annotation.implicitNotFound + +@implicitNotFound("No member of type class Show could be found for ${T}") +trait Show[-T] { + def show(t: T): String +} + +object Show { + implicit class ShowValue[V](val v: V) extends AnyVal { + def show(implicit ev: Show[V] = null): String = + if (ev != null) ev.show(v) + else v.toString + } + + implicit val stringShow = new Show[String] { + //charEscapeSeq ::= ‘\‘ (‘b‘ | ‘t‘ | ‘n‘ | ‘f‘ | ‘r‘ | ‘"‘ | ‘'‘ | ‘\‘) + def show(str: String) = + "\"" + + str + .replaceAll("\b", "\\\\b") + .replaceAll("\t", "\\\\t") + .replaceAll("\n", "\\\\n") + .replaceAll("\f", "\\\\f") + .replaceAll("\r", "\\\\r") + .replaceAll("\'", "\\\\'") + .replaceAll("\"", "\\\\\"") + + "\"" + } + + implicit val intShow = new Show[Int] { + def show(i: Int) = i.toString + } + + implicit val floatShow = new Show[Float] { + def show(f: Float) = f + "f" + } + + implicit val doubleShow = new Show[Double] { + def show(d: Double) = d.toString + } + + implicit val charShow = new Show[Char] { + def show(c: Char) = "'" + (c match { + case '\b' => "\\b" + case '\t' => "\\t" + case '\n' => "\\n" + case '\f' => "\\f" + case '\r' => "\\r" + case '\'' => "\\'" + case '\"' => "\\\"" + case c => c + }) + "'" + } + + object List { + implicit def showList[T](implicit st: Show[T]) = new Show[List[T]] { + def show(xs: List[T]) = + if (xs.isEmpty) "Nil" + else "List(" + xs.map(_.show).mkString(", ") + ")" + } + + implicit val showNil = new Show[List[Nothing]] { + def show(xs: List[Nothing]) = "Nil" + } + } + + object Option { + implicit def showOption[T](implicit st: Show[T]) = new Show[Option[T]] { + def show(ot: Option[T]): String = ot match { + case Some(t) => "Some("+ st.show(t) + ")" + case none => "None" + } + } + + implicit val showNone = new Show[Option[Nothing]] { + def show(n: Option[Nothing]) = "None" + } + } + + object Map { + implicit def showMap[K, V](implicit sk: Show[K], sv: Show[V]) = new Show[Map[K, V]] { + def show(m: Map[K, V]) = + "Map(" + m.map { case (k, v) => sk.show(k) + " -> " + sv.show(v) } .mkString (", ") + ")" + } + } +} |