There has been a feature in TextMate (more specifically 1, but it is sorta supported in 2) that was the sole reason that I continued to use it for years. With the upgrade to Mavericks, and the forced upgrade to TextMate 2.0 I have been searching for a replacement editor for a while…so far Atom seems like it!
In the lower right section of TM, there was a select drop down that listed all of the functions (classes, things, depending on the language grammar). This allowed me to have both a quick glance at what is available in a file when I am first looking at it (or first opening after a very long while), and also gave me a set of bookmarks to quick jump to where that object is defined. In TM 1, there was an option to sort these alphabetically. Here is an imgur picture showing this drop down.
I am posting here, as I don’t quite have time to start working on this…and perhaps there are those that do. Happy coding!!