Sorting overloads in completion

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/CompletionSession.kt

@@ -272,6 +272,8 @@ abstract class CompletionSession(
 
         sorter = sorter.weighBefore("middleMatching", PreferMatchingItemWeigher)
 
+        sorter = sorter.weighAfter("kotlin.proximity", ByNameAlphabeticalWeigher, PreferLessParametersWeigher)
+
         return sorter
     }
 

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/Weighers.kt

@@ -281,4 +281,19 @@ class PreferContextElementsWeigher(private val context: DeclarationDescriptor) :
 
         return original in contextElements
     }
+}
+
+object ByNameAlphabeticalWeigher : LookupElementWeigher("kotlin.byNameAlphabetical") {
+    override fun weigh(element: LookupElement): String? {
+        val lookupObject = element.`object` as? DeclarationLookupObject ?: return null
+        return lookupObject.name?.asString()
+    }
+}
+
+object PreferLessParametersWeigher : LookupElementWeigher("kotlin.preferLessParameters") {
+    override fun weigh(element: LookupElement): Int? {
+        val lookupObject = element.`object` as? DeclarationLookupObject ?: return null
+        val function = lookupObject.descriptor as? FunctionDescriptor ?: return null
+        return function.valueParameters.size
+    }
 }

idea/idea-completion/testData/basic/common/PreferLessParameters.kt

@@ -0,0 +1,10 @@
+fun foo(iterable: Iterable<String>) {
+    iterable.singl<caret>
+}
+
+// WITH_ORDER
+// EXIST: { itemText: "single", tailText: "() for Iterable<T> in kotlin" }
+// EXIST: { itemText: "single", tailText: " {...} (predicate: (String) -> Boolean) for Iterable<T> in kotlin" }
+// EXIST: { itemText: "singleOrNull", tailText: "() for Iterable<T> in kotlin" }
+// EXIST: { itemText: "singleOrNull", tailText: " {...} (predicate: (String) -> Boolean) for Iterable<T> in kotlin" }
+// NOTHING_ELSE

idea/idea-completion/testData/weighers/smart/FunctionExpected.kt

@@ -12,4 +12,5 @@ fun bar(p: (String) -> Boolean) {
 // ORDER: {...}
 // ORDER: { String -> ... }
 // ORDER: ::x
+// ORDER: ::TODO
 // ORDER: ::error

idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/JSBasicCompletionTestGenerated.java

@@ -625,6 +625,12 @@ public class JSBasicCompletionTestGenerated extends AbstractJSBasicCompletionTes
             doTest(fileName);
         }
 
+        @TestMetadata("PreferLessParameters.kt")
+        public void testPreferLessParameters() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/PreferLessParameters.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("PrivatesInSecondPressCompletion.kt")
         public void testPrivatesInSecondPressCompletion() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/PrivatesInSecondPressCompletion.kt");

idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/JvmBasicCompletionTestGenerated.java

@@ -625,6 +625,12 @@ public class JvmBasicCompletionTestGenerated extends AbstractJvmBasicCompletionT
             doTest(fileName);
         }
 
+        @TestMetadata("PreferLessParameters.kt")
+        public void testPreferLessParameters() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/PreferLessParameters.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("PrivatesInSecondPressCompletion.kt")
         public void testPrivatesInSecondPressCompletion() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/PrivatesInSecondPressCompletion.kt");