47884 2010-10-18 22:54:17 -0700 should we allow multiple inheritance in python code in webkit? 2010-10-21 16:42:16 -0700 1 1 1 Unclassified WebKit Tools / Tests 528+ (Nightly build) PC OS X 10.5 RESOLVED FIXED P2 Normal --- 1 dpranke webkit-unassigned abarth eric levin ojan tony oldest_to_newest 296010 0 dpranke 2010-10-18 22:54:17 -0700 See bug 47874 for some background ... there are places in the code where using MI would make the code cleaner, like webkitpy/layout_tests/port/{google_chrome,chromium_gpu}.py , where the classes naturally want some sort of diamond and/or mixin behavior, and we resort to unpleasantness in its absence. 296016 1 abarth 2010-10-18 22:57:05 -0700 We use multiple inheritance in a bunch of places in webkitpy, mostly int the Mixin pattern. 296017 2 abarth 2010-10-18 22:57:30 -0700 Actually, also to inherit from "pure virtual" interfaces. 296243 3 tony 2010-10-19 09:56:48 -0700 I'm fine with pure virtual interfaces and to a lesser degree, mixin. The proper way to refactor the google_chrome and chromium_gpu ports would be to have delegate classes for specific functionality of a port. For example, having a delegate that provides a few path functions (e.g., baseline search path and path to expectations) and have it be a member variable of Port. This could also be done via mixins, but I think the delegate pattern is more widely used in WebKit code. 296244 4 tony 2010-10-19 09:59:07 -0700 To clarify, I think what we want to avoid is a GPU port and a Linux port where we inherit from both to make a Linux GPU port. That would be confusing because you don't know what functions are provided by which base class. 297718 5 dpranke 2010-10-21 16:42:16 -0700 I think I will consider this closed as "yes, with caution". Anyone please reopen or comment if you disagree :)