You can get away without any coding if you need bookmarked directories in bash (and possibly other shells): create a directory somewhere to hold your bookmarks (maybe ~/.dirbookmarks) and add it to your $CDPATH. Now fill the bookmark directory with symlinks to the bookmarked locations and you can cd <somebookmark> directly regardless of where you are. Filename completion on the bookmarks works too. Additionally after a complete -d cd for convenience, bash will only complete directory names when you type cd.

Of course, all this presumes you're on a system that supports symlinks.

Makeshifts last the longest.