On Jan 27, 2011, at 4:38 PM, Dirk Pranke wrote: > I agree with all of the sentiments below, except for possibly one or two > cases. > > Namely, sometimes you write code where the "what" is not obvious. In > that situation, it may not be possible to change the code to make it > more obvious, because you are bound by contract. For example, suppose > you are implementing an interface with a method called sort(). The > fact that you choose a quicksort or a mergesort is a useful one-line > comment, and in my opinion is probably better than just wrapping a > method called quicksort() and hoping it gets inlined away.
I ran into this exact situation. I wanted to add a sort function that doesn't copy, only swaps. It happens that heapsort is such an algorithm. I named the public interface nonCopyingSort, made it call a function named heapSort, and wrote a comment explaining why heapSort is an appropriate implementation for nonCopyingSort: http://trac.webkit.org/browser/trunk/Source/JavaScriptCore/wtf/NonCopyingSort.h template<typename RandomAccessIterator, typename Predicate> inline void nonCopyingSort(RandomAccessIterator start, RandomAccessIterator end, Predicate compareLess) { // heapsort happens to use only swaps, not copies, but the essential thing about // this function is the fact that it does not copy, not the specific algorithm heapSort(start, end, compareLess); } Inlining works. IMO it's always better to use a well-named function to document what your code does than a comment. In this case I did it even though I also had a comment explaining why the function uses heapsort. > > A slight variant of this is that you may be learning or > reverse-engineering code where the "what" is not clear (perhaps > because it was poorly rewritten). In the longer-term, ideally you'd > clean up the code, but in the short term it might be useful to capture > the "what" in comments until you can safely refactor things and delete > the comments. I would prefer for people to refactor instead of adding explanatory comments. In general, I agree with what Eric and Darin said about this topic. Regards, Maciej _______________________________________________ webkit-dev mailing list [email protected] http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
