Exuberant Ctags is an essential complement to Vim: it generates an index of symbol names (tags) for a set of source files. In Vim, just place the cursor on a function name and type C-] to go to its definition.

Ctags works well for most of the languages that I deal with, but falls down badly on modern JavaScript. Its built-in parser simply doesn’t handle de­c­la­ra­tions like these:

Sizzle.selectors.filters.animated = function(elem) { // ...
ajaxSetup: function( settings ) {

I came across Unbad‘s workaround earlier tonight. His code didn’t work for me, so I hacked on it until it did:

--langdef=js
--langmap=js:.js
--regex-js=/([A-Za-z0-9._$]+)[ \t]*[:=][ \t]*\{/\1/,object/
--regex-js=/([A-Za-z0-9._$()]+)[ \t]*[:=][ \t]*function[ \t]*\(/\1/,function/
--regex-js=/function[ \t]+([A-Za-z0-9._$]+)[ \t]*\(([^)])\)/\1/,function/
--regex-js=/([A-Za-z0-9._$]+)[ \t]*[:=][ \t]*\[/\1/,array/
--regex-js=/([^= ]+)[ \t]*=[ \t]*[^"]'[^']*/\1/,string/
--regex-js=/([^= ]+)[ \t]*=[ \t]*[^']"[^"]*/\1/,string/

Simply add the above to ~/.ctags or $HOME/ctags.cnf.