stream: simpler stream constructon

Adds simplified constructor pattern, allowing users
to provide "read", "write", "transform", "flush", and
"writev" functions as stream options in lieu of subclassing.

Semver: minor
PR-URL: https://github.com/iojs/io.js/pull/697
Fixes: https://github.com/iojs/readable-stream/issues/102
Reviewed-By: Chris Dickinson <christopher.s.dickinson@gmail.com>

1 files changed, 73 insertions, 2 deletions

diff --git a/doc/api/stream.markdown b/doc/api/stream.markdown
index 943718660c..bbd2af0d7a 100644
--- a/doc/api/stream.markdown
+++ b/doc/api/stream.markdown
@@ -718,7 +718,7 @@ of stream class you are writing:
       <p>[Writable](#stream_class_stream_writable_1)</p>
     </td>
     <td>
-      <p><code>[_write][]</code></p>
+      <p><code>[_write][]</code>, <code>_writev</code></p>
     </td>
   </tr>
   <tr>
@@ -729,7 +729,7 @@ of stream class you are writing:
       <p>[Duplex](#stream_class_stream_duplex_1)</p>
     </td>
     <td>
-      <p><code>[_read][]</code>, <code>[_write][]</code></p>
+      <p><code>[_read][]</code>, <code>[_write][]</code>, <code>_writev</code></p>
     </td>
   </tr>
   <tr>
@@ -1315,6 +1315,77 @@ for examples and testing, but there are occasionally use cases where
 it can come in handy as a building block for novel sorts of streams.
 
 
+## Simplified Constructor API 
+
+<!--type=misc-->
+
+In simple cases there is now the added benefit of being able to construct a stream without inheritance.
+
+This can be done by passing the appropriate methods as constructor options:
+
+Examples:
+
+### Readable
+```javascript
+var readable = new stream.Readable({
+  read: function(n) {
+    // sets this._read under the hood
+  }
+});
+```
+
+### Writable
+```javascript
+var writable = new stream.Writable({
+  write: function(chunk, encoding, next) {
+    // sets this._write under the hood
+  }
+});
+
+// or
+
+var writable = new stream.Writable({
+  writev: function(chunks, next) {
+    // sets this._writev under the hood
+  }
+});
+```
+
+### Duplex
+```javascript
+var duplex = new stream.Duplex({
+  read: function(n) {
+    // sets this._read under the hood
+  },
+  write: function(chunk, encoding, next) {
+    // sets this._write under the hood
+  }
+});
+
+// or
+
+var duplex = new stream.Duplex({
+  read: function(n) {
+    // sets this._read under the hood
+  },
+  writev: function(chunks, next) {
+    // sets this._writev under the hood
+  }
+});
+```
+
+### Transform
+```javascript
+var transform = new stream.Transform({
+  transform: function(chunk, encoding, next) {
+    // sets this._transform under the hood
+  },
+  flush: function(done) {
+    // sets this._flush under the hood
+  }
+});
+```
+
 ## Streams: Under the Hood
 
 <!--type=misc-->