diff options
| -rw-r--r-- | Scala/sandbox/0-main.scala | 1 | ||||
| -rw-r--r-- | Scala/sandbox/8-pattern-matching.scala | 29 |
2 files changed, 30 insertions, 0 deletions
diff --git a/Scala/sandbox/0-main.scala b/Scala/sandbox/0-main.scala index 6f0edf3..b68b57e 100644 --- a/Scala/sandbox/0-main.scala +++ b/Scala/sandbox/0-main.scala @@ -10,5 +10,6 @@ object Main extends App { IntList.run Natural.run Variance.run + PatternMatching.run } diff --git a/Scala/sandbox/8-pattern-matching.scala b/Scala/sandbox/8-pattern-matching.scala new file mode 100644 index 0000000..36beb68 --- /dev/null +++ b/Scala/sandbox/8-pattern-matching.scala @@ -0,0 +1,29 @@ +object PatternMatching +{ + trait Expr { + def eval: Int = this match { + case Number(n) => n + case Sum(e1, e2) => e1.eval + e2.eval + } + def show: String = this match { + case Number(n) => n.toString + case Sum(e1, e2) => e1.show + " + " + e2.show + } + } + + case class Number(n: Int) extends Expr + case class Sum(e1: Expr, e2: Expr) extends Expr + + + def eval1(e: Expr): Int = e match { + case Number(n) => n + case Sum(e1, e2) => eval1(e1) + eval1(e2) + } + + def run = { + println("PatternMatching") + println( eval1(Sum(Number(1), Number(2))) ) + val e = Sum(Number(1), Number(2)) + println( e.show + " = " + e.eval ) + } +} |