Changeset 6675 for lang/scala/sandbox

Timestamp:

02/14/08 18:27:46 (10 months ago)

Author:

keisuken

Message:

Loop method updated. method name is while and foreach to find.

Location:

lang/scala/sandbox

Files:

• src/jp/ne/cappuccino/keisuken/scl/lang/Loop.scala (modified) (2 diffs)
• webpages/lib/scala-sandbox.jar (modified) (previous)

lang/scala/sandbox/src/jp/ne/cappuccino/keisuken/scl/lang/Loop.scala

@@ -3 +3 @@
 object Loop {
 
-  class Break(var cond: Boolean) {
-    def this() = this(true)
-    def apply(): Unit = cond = false
+  class Break[T](var cond: Boolean, var value: Option[T]) {
+    def this() = this(true, None)
+    def apply(): Unit = {cond = false; value = None}
+    def apply(v: T): Unit = {cond = false; value = Some(v)}
   }
 
-  def forLoop[A](iterable: Iterable[A])(f: (A, Break) => Unit): Unit = {
-    val break = new Break()
+  def find[A, B]
+    (iterable: Iterable[A])(f: (A, Break[B]) => Unit): Option[B] = {
+    val break = new Break[B]()
     val iterator = iterable.elements
-    while(break.cond) {
+    while(break.cond && iterator.hasNext) {
       val value = iterator.next
       if(value != null) {
@@ -19 +21 @@
       }
     }
+    break.value
   }
 
-  def whileLoop(cond: () => Boolean)(f: Break => Unit): Unit = {
-    val break = new Break()
-    while(break.cond && cond()) f(break)
+  def find[A](cond: => Boolean)(f: Break[A] => Unit): Option[A] = {
+    val break = new Break[A]()
+    while(break.cond && cond) f(break)
+    break.value
   }
 
   def main(args: Array[String]) {
     var i = 0
-    whileLoop(() => i < 10) {break =>
-      if(i == 5)
-        break()
+    find[Int](true) {break =>
+      if(i >= 5)
+        break(i)
       else
         i += 1
+    } match {
+      case Some(result) => println(result)
+      case None => println("Not found")
     }
-    println(i)
-    forLoop(Array("abc", "cde", "efg")) {(value, break) =>
-      if(value.equals("efg"))
-        break()
-      else
-        println(value)
+    val result = find[String, String](Array("aaa", "bbb", "ccc"))
+    {(value, break) =>
+      if(value.equals("ddd"))
+        break(value)
     }
-  }
+    println(result)
+ }
 }