From 4167359c084b5af684c36b4112f74841db4dfdcf Mon Sep 17 00:00:00 2001
From: Ilya Ryzhenkov <orangy@jetbrains.com>
Date: Mon, 9 Jun 2014 23:24:45 +0400
Subject: [PATCH] Map.filter() returns Map instead of List of Entries

---
 libraries/stdlib/src/generated/_Filtering.kt       | 12 +++++++++---
 .../kotlin-stdlib-gen/src/templates/Filtering.kt   | 14 ++++++++++++++
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/libraries/stdlib/src/generated/_Filtering.kt b/libraries/stdlib/src/generated/_Filtering.kt
index f6e08fa2531..fdc46e28a27 100644
--- a/libraries/stdlib/src/generated/_Filtering.kt
+++ b/libraries/stdlib/src/generated/_Filtering.kt
@@ -432,10 +432,16 @@ public inline fun <T> Iterable<T>.filter(predicate: (T) -> Boolean): List<T> {
 }
 
 /**
- * Returns a list containing all elements matching the given *predicate*
+ * Returns a map containing all key-value pairs matching the given *predicate*
  */
-public inline fun <K, V> Map<K, V>.filter(predicate: (Map.Entry<K, V>) -> Boolean): List<Map.Entry<K, V>> {
-    return filterTo(ArrayList<Map.Entry<K, V>>(), predicate)
+public inline fun <K, V> Map<K, V>.filter(predicate: (Map.Entry<K, V>) -> Boolean): Map<K, V> {
+    val result = HashMap<K,V>()
+    for (entry in this) {
+        if (predicate(entry)) {
+            result.put(entry.key, entry.value)
+        }
+    }
+    return result
 }
 
 /**
diff --git a/libraries/tools/kotlin-stdlib-gen/src/templates/Filtering.kt b/libraries/tools/kotlin-stdlib-gen/src/templates/Filtering.kt
index 5a17166734d..9547e89cb00 100644
--- a/libraries/tools/kotlin-stdlib-gen/src/templates/Filtering.kt
+++ b/libraries/tools/kotlin-stdlib-gen/src/templates/Filtering.kt
@@ -205,7 +205,21 @@ fun filtering(): List<GenericFunction> {
             return FilteringStream(this, true, predicate)
             """
         }
+
         include(Maps)
+        doc(Maps) { "Returns a map containing all key-value pairs matching the given *predicate*" }
+        returns(Maps) { "Map<K, V>" }
+        body(Maps) {
+            """
+            val result = HashMap<K,V>()
+            for (entry in this) {
+                if (predicate(entry)) {
+                    result.put(entry.key, entry.value)
+                }
+            }
+            return result
+            """
+        }
     }
 
     templates add f("filterTo(destination: C, predicate: (T) -> Boolean)") {