Extend the document, class, method, ... searcher to not only search for the exact matches but by the order of letters as well. For an example: currently if you press Control + k (or Cmd + k) and start to type "MyCat" it will show only the results which contains "MyCat" exactly. It would be useful to present the file, class, method, ... names which contains these letters in this order, but not necessarily following each other. In this case it would also show "MyLittleCat" as well.

This is the search-system/algorithm XCode uses and it's very useful most of the times, especially if I don't know an exact part of the name of the file, class, ... which I'm looking for only a "strong guess" (like in the example I know it contains "My" and "Cat" but I don't know that "Little" is between these parts).