Merge pull request #67 from zenhack/typescript-decl-fix

Small fix in the typescript declarations, and add some comments.

src/node-capnp/capnp.d.ts

@@ -2,10 +2,20 @@ declare module Capnp {
   type Id = string;
 
   abstract class StructSchema<Builder, Reader> {
+    // A schema for a struct type. The `Builder` parameter is what users of
+    // the library specify in order to create a value; it may be missing fields,
+    // which will be filled in with defaults. A `Reader` is what is is returned
+    // when parsing a value, and is guaranteed to have all known fields set.
+
     typeId: Id;
   }
 
   abstract class InterfaceSchema<Server, Client> {
+    // A schema for an interface type. Similarly to `StructSchema`, the `Server`
+    // and `Client` parameters represent objects which may have missing
+    // methods (for servers), and ones which do not (for clients, though calling
+    // the method may still throw unimplemented).
+
     typeId: Id;
   }
 
@@ -29,7 +39,7 @@ declare module Capnp {
   }
 
   function parse<Builder, Reader>(type: StructSchema<Builder, Reader>, buffer: Buffer): Reader;
-  function serialize<Builder, Reader>(type: StructSchema<Builder, Reader>, reader: Reader): Buffer;
+  function serialize<Builder, Reader>(type: StructSchema<Builder, Reader>, builder: Builder): Buffer;
   function connect(addr: string): Connection;
 }
 export default Capnp;