diff --git a/Array.js b/Array.js
index 5809cd3..5d868dc 100644
--- a/Array.js
+++ b/Array.js
@@ -212,9 +212,12 @@ object.Mixin('ArrayMixin', 'soft', {
 			// done...
 			: [] },
 
-	// XXX add handler function support -- a-la generator.js'
-	iter: function*(lst=[]){
-		yield* lst.iter() },
+	// XXX not sure about the handler API here yet... 
+	iter: function*(lst=[], handler=undefined){
+		yield* lst.iter(
+			...(handler ? 
+				[handler] 
+				: [])) },
 })
 
 
diff --git a/Function.js b/Function.js
new file mode 100644
index 0000000..4b36aea
--- /dev/null
+++ b/Function.js
@@ -0,0 +1,18 @@
+/**********************************************************************
+* 
+*
+*
+**********************************************/  /* c8 ignore next 2 */
+((typeof define)[0]=='u'?function(f){module.exports=f(require)}:define)
+(function(require){ var module={} // make module AMD/node compatible...
+/*********************************************************************/
+
+
+var AsyncFunction =
+module.AsyncFunction =
+	(async function(){}).constructor
+
+
+
+/**********************************************************************
+* vim:set ts=4 sw=4 :                               */ return module })
diff --git a/README.md b/README.md
index 09a6f49..4b39170 100644
--- a/README.md
+++ b/README.md
@@ -13,6 +13,8 @@ Library of JavaScript type extensions, types and utilities.
     - [`Object.matchPartial(..)`](#objectmatchpartial)
     - [`<object>.run(..)`](#objectrun)
     - [`Object.sort(..)`](#objectsort)
+  - [`Function`](#function)
+    - [`func.AsyncFunction`](#funcasyncfunction)
   - [`Array`](#array)
     - [`<array>.first(..)` / `<array>.last(..)`](#arrayfirst--arraylast)
     - [`<array>.rol(..)`](#arrayrol)
@@ -454,6 +456,30 @@ Object.keys(Object.sort(o, ['x', 'a', '100']))
 This is similar to [`<map>.sort(..)`](#mapsort) and [`<ser>.sort(..)`](#setsort).
 
 
+## `Function`
+
+```javascript
+var func = require('ig-types/Function')
+```
+
+### `func.AsyncFunction`
+
+The async function constructor.
+
+This enables us to test if an object is an instance of an async function. 
+
+```javascript
+var a = async function(){
+    // ...
+}
+
+a instanceof func.AsyncFunction // -> true
+```
+
+This is hidden by JavaScript by default.
+
+
+
 ## `Array`
 
 ```javascript
diff --git a/main.js b/main.js
index af776f8..c30b6f1 100644
--- a/main.js
+++ b/main.js
@@ -22,6 +22,7 @@ module.patchDate = require('./Date').patchDate
 
 // Additional types...
 module.containers = require('./containers')
+module.func = require('./Function')
 module.generator = require('./generator')
 module.event = require('./event')
 module.runner = require('./runner')
@@ -31,7 +32,9 @@ module.runner = require('./runner')
 module.STOP = object.STOP
 
 // frequently used stuff...
+module.AsyncFunction = module.func.AsyncFunction
 module.Generator = module.generator.Generator
+module.AsyncGenerator = module.generator.AsyncGenerator
 // XXX doc...
 module.iter = module.generator.iter
 
diff --git a/package.json b/package.json
index 2cbe382..26cdae0 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "ig-types",
-  "version": "6.15.6",
+  "version": "6.15.7",
   "description": "Generic JavaScript types and type extensions...",
   "main": "main.js",
   "scripts": {