Proposed change to readObject().

The purpose is to
- Ensure type checking for "fail-fast" detection of streaming errors.
- But simplify it so that callers don't have to cast themselves and
  potentially screw up by using "String(obj)" or "Array(obj)", or miss out
  on the fail-fastyness by using "obj as SomeType".
- But, at the same time, allow for the sveltest code possible.
    // first one is a bit shorter!
    _name = ins.readObject(Name);
    _name = Name(ins.readObject());

    // first one is a bit shorter!
    _state = ins.readObject(String);
    _state = ins.readObject() as String;


So, to sum up: the code is the shortest and doesn't require special-casing
if you are reading a String, Number, int, uint, Boolean, or Array.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@5984 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/as/com/threerings/io/ObjectInputStream.as

@@ -62,13 +62,16 @@ public class ObjectInputStream
     }
 
     /**
-     * Attempts to read the next object from the stream. If a type is passed and the read object's
-     * type doesn't match, a <code>TypeError</code> is thrown.
-     * @param type optional type to check the read object against
+     * Reads the next Object (or null) from the stream and returns it as * so that you may assign
+     * to any variable without casting. It is strongly recommended that you pass a 'checkType'
+     * parameter so that the type of the Object is verified to be what you believe it to be,
+     * thus helping you detect streaming errors as quickly as possible.
+     *
+     * @param checkType optional type to check the read object against
+     * @return the Object read, or null.
      * @throws TypeError if the object is read successfully but is the wrong type
-     * @return null if the object could not be read (or is actually null)
      */
-    public function readObject (type :Class = null) :Object
+    public function readObject (checkType :Class = null) :*
         //throws IOError
     {
         var DEBUG_ID :String = "[" + (++_debugObjectCounter) + "] ";
@@ -121,9 +124,9 @@ public class ObjectInputStream
             //log.debug("Reading object...");
             readBareObjectImpl(target, cmap.streamer);
             if (DEBUG) log.debug(DEBUG_ID + "Read object: " + target);
-            if (type != null && !(target is type)) {
+            if (checkType != null && !(target is checkType)) {
                 throw new TypeError(
-                    "Cannot convert " + ClassUtil.getClass(target) + " to " + type);
+                    "Cannot convert " + ClassUtil.getClass(target) + " to " + checkType);
             }
             return target;