rev 498 - in trunk: docs/tutorial pr/test src

Author: mark
Date: 2004-05-17 23:42:07 -0400 (Mon, 17 May 2004)
New Revision: 498

Modified:
   trunk/docs/tutorial/tutorial8.htm
   trunk/pr/test/test.pr
   trunk/src/object.c
Log:
fixed bug that caused symbols to be garbage collected

Modified: trunk/docs/tutorial/tutorial8.htm
===================================================================
--- trunk/docs/tutorial/tutorial8.htm	2004-05-18 01:51:43 UTC (rev 497)
+++ trunk/docs/tutorial/tutorial8.htm	2004-05-18 03:42:07 UTC (rev 498)
@@ -167,8 +167,29 @@
           "Prototype". Now you can see what our original statement "Rectangle 
           = Object()" was doing. It created an empty object with only a prototype 
           link to Object.</p>
+        <pre>>>> rect2 = Rectangle()
+>>> print rect2.attrs()  # attrs() returns attrs as dictionary
+{}
+>>> print rect2.width, rect2.height, rect2.area()
+10 10 100
+>>></pre>
+        <p>We created a new object called rect2 with no attributes as before, 
+          but this time we gave it a prototype link to Rectangle instead of copying 
+          it from Rectangle. We showed that it had no attributes of it's own by 
+          printing them out using the .attrs() function. Yet when we accessed 
+          width, height, and area we got the same results as before. This is because 
+          each of the attribute lookups, both for data and functions, failed on 
+          rect2 so the lookup went to Rectangle where the lookup succeeded. </p>
+        <p>In the case of rect2.area() resolving to Rectangle.area(), this kind 
+          of method lookup reminds us a lot of the method inheritance in object-oriented 
+          programming. So we sometimes say in Prothon that rect2 &quot;inherited&quot; 
+          the method area from Rectangle. In Prothon, we also &quot;inherit&quot; 
+          data since we lookup all attributes in the prototype parents. This is 
+          not done in object-oriented languages and it is a powerful advantage 
+          of prototype-based languages. Let's continue the example:</p>
         <p>&nbsp;</p>
-        </td>
+        <p>&nbsp;</p>
+      </td>
     </tr>
   </table>
   <table width="630" border="0" cellpadding="0" cellspacing="0">
Modified: trunk/pr/test/test.pr
===================================================================
--- trunk/pr/test/test.pr	2004-05-18 01:51:43 UTC (rev 497)
+++ trunk/pr/test/test.pr	2004-05-18 03:42:07 UTC (rev 498)
@@ -6,5 +6,5 @@
     height = 10
     def area():
         return self.width * self.height
-rect2 = Rectangle()
 
+

Modified: trunk/src/object.c
===================================================================
--- trunk/src/object.c	2004-05-18 01:51:43 UTC (rev 497)
+++ trunk/src/object.c	2004-05-18 03:42:07 UTC (rev 498)
@@ -1106,10 +1106,8 @@
 	if (!sym_obj) {
 		raise_exception(ist, OBJ(INTERNAL_EXC), "key_to_symstr sym lookup error");
 		res = "";
-	} else {
+	} else
 		res = symch(ist, sym_obj);
-		del_unlock(sym_obj);
-	}
 	del_unlock(key_obj);
 	return res;
 }