Cleaner range counting.

Plus a big unit test I had lying around.

1 files changed, 55 insertions, 0 deletions

diff --git a/test/files/run/range-unit.scala b/test/files/run/range-unit.scala
new file mode 100644
index 0000000000..ece0d9806c
--- /dev/null
+++ b/test/files/run/range-unit.scala
@@ -0,0 +1,55 @@
+import scala.collection.immutable.Range
+
+object Test {
+  // ha ha, I always forget math.abs(Int.MinValue) == Int.MinValue
+  val numbers = (
+    ( (-3 to 3) ++ List(17, 127, Int.MaxValue, Int.MinValue + 1)
+    ).distinct.sortBy(n => (math.abs(n), n))
+  ) :+ Int.MinValue
+  
+  // reducing output a little
+  val endpoints = numbers filterNot Set(-3, -2, 2, 17, 127)
+  
+  def num(n: Int) = {
+    val frommax = Int.MaxValue - n
+    val frommin = Int.MinValue - n
+    
+    if (n > 0) {
+      if (frommax == 0) "MAX"
+      else if (frommax < 1000) "MAX-" + frommax
+      else "" + n
+    }
+    else {
+      if (frommin == 0) "MIN"
+      else if (frommin > -1000) "MIN+" + (-frommin)
+      else "" + n
+    }
+  }
+  
+  def run[T](body: => Range): List[Any] = {
+    try   { val r = body ; if (r.isEmpty) List(r.length) else List(num(r.length), num(r.head), num(r.last)) }
+    catch { case e: IllegalArgumentException => List("---\n    " + e) }
+  }
+
+  def runGroup(label: String, f: (Int, Int, Int) => Range) {
+    println(">>> " + label + " <<<\n")
+    for (start <- endpoints) {
+      val s = "%-7s %-7s %-7s %s".format("start", "end", "step", "length/first/last")
+      println(s  + "\n" + ("-" * s.length))
+      for (end <- endpoints ; step <- numbers) {
+        print("%-7s %-7s %-7s ".format(num(start), num(end), num(step)))
+        println(run(f(start, end, step)).mkString("/"))
+      }
+      println("")
+    }
+  }
+
+  def main(args: Array[String]): Unit = {
+    runGroup("Range.inclusive", Range.inclusive(_, _, _))
+    runGroup("Range.apply", Range.apply(_, _, _))
+    runGroup("start to end", (x, y, _) => x to y)
+    runGroup("start to end by step", _ to _ by _)
+    runGroup("start until end", (x, y, _) => x until y)
+    runGroup("start until end by step", _ until _ by _)
+  }
+}