From d296d64027626b77bf33cc2a0c01fa40891048f6 Mon Sep 17 00:00:00 2001
From: Alexander Udalov <Alexander.Udalov@jetbrains.com>
Date: Mon, 4 Jun 2012 17:41:28 +0400
Subject: [PATCH 1/2] File.listFiles(filter)

---
 libraries/stdlib/src/kotlin/io/Files.kt | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/libraries/stdlib/src/kotlin/io/Files.kt b/libraries/stdlib/src/kotlin/io/Files.kt
index 52b24387fab..8b46f8ccf76 100644
--- a/libraries/stdlib/src/kotlin/io/Files.kt
+++ b/libraries/stdlib/src/kotlin/io/Files.kt
@@ -202,3 +202,12 @@ fun File.readLines(charset : String = "UTF-8") : List<String> {
 
     return rs
 }
+
+/**
+ * Returns an array of files and directories in the directory that satisfy the specified filter.
+ */
+fun File.listFiles(filter : (file : File) -> Boolean) : Array<File>? = listFiles(
+    object : FileFilter {
+        override fun accept(file: File?) = filter(file!!)
+    }
+) as Array<File>?

From 9a7f3da6c6940536340bbf91608296169eda12ae Mon Sep 17 00:00:00 2001
From: Alexander Udalov <Alexander.Udalov@jetbrains.com>
Date: Mon, 4 Jun 2012 19:57:31 +0400
Subject: [PATCH 2/2] test for File.listFiles(filter)

---
 libraries/stdlib/test/IoTest.kt | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/libraries/stdlib/test/IoTest.kt b/libraries/stdlib/test/IoTest.kt
index 5d46da4571f..98591f67527 100644
--- a/libraries/stdlib/test/IoTest.kt
+++ b/libraries/stdlib/test/IoTest.kt
@@ -71,4 +71,19 @@ class IoTest() : TestCase() {
 
     assertEquals(arrayList("Hello", "World"), list)
   }
+  
+  fun testListFiles() {
+    val dir = File.createTempFile("temp", System.nanoTime().toString())!!
+    dir.delete()
+    dir.mkdir()
+    
+    File.createTempFile("temp", "1.kt", dir)
+    File.createTempFile("temp", "2.java", dir)
+    File.createTempFile("temp", "3.kt", dir)
+    
+    val result = dir.listFiles { it.getName()!!.endsWith(".kt") }
+    
+    assertNotNull(result)
+    assertEquals(result!!.size, 2)
+  }
 }