How delegates impose contracts on their wrappers

Eric | November 15, 2007

This week I was working a lot on our new PLDI submission, which we just submitted (more about that later). During this work I came around an interesting subtlety with respect to delegates and Design By Contract (DBC) . We wanted to validate the fulfillment of a contract for the Iterator interface: When using an iterator i you are only allowed to call if before that you have checked whether i.hasNext() holds. For PLDI we developed a static analysis approach (using tracematches) that allows you to flag potential violations of this contract. Here is one that we found in Jython, a Python implementation for the Java Virtual Machine and part of the DaCapo benchmark suite:

Read the rest of this entry »

Comments Off on How delegates impose contracts on their wrappers
Bug finding, Java, Programming