collect size

src/FilesSize.kt

@@ -0,0 +1,16 @@
+import java.nio.file.Files
+import java.nio.file.Path
+import java.util.stream.Collectors
+
+fun main() {
+    val home = Path.of("/Users/jonnyzzz/Work/intellij-community")
+    val r = Files.walk(home).parallel()
+        .filter { Files.isRegularFile(it) }
+        .filter {
+        val name = it.fileName.toString()
+        name.endsWith(".java") ||
+        name.endsWith(".kt")
+    }.map { Files.size(it) }.collect(Collectors.summingLong { it })
+
+    println("Java + Kotlin size: $r")
+}