The Old New Thing

Writing a sort comparison function

October 23, 2003 Oct 23, 2003 10/23/03

Raymond Chen

When you are writing a sort comparison function (say, to be passed to or *gasp* to be used as an ), your comparison function needs to follow these rules: Reflexivity: . Anti-Symmetry: has the opposite sign of , where 0 is considered to be its own opposite. Transitivity: If and , then . Here are some logical consequences of these rules...