Faster multi-file keyword completion in Vim?

Question

While searching for my python completion nirvana in vim, I have come to really love <C-x> <C-i>: "keywords in the current and included files". This almost always gets me a long nasty name from another module completed, which is great.

(Omni-completion is obviously better when it works, but too often it reports it can't find any matches. Ok, Python isn't Java, I get it)

The only problem with this multi-file completion is it's very slow: on my netbook, a file with a reasonable set of imports can take up to 4 or 5 seconds to parse every time I hit <C-x> <C-i>. It seems to load every imported file every time I hit <C-x> <C-i>. Is there any way to cache the files or speed up this process? Would using tag completion be faster?

Answer 1

It is quite possible that this process takes some time if you're working on projects with multiple source files (vim needs to parse all included source files to find more included source files and to build the word list.) You could use tag-completion, which uses the output of ctags to do almost the same, but you'd need to run a few tests to tell the speed difference.

I personally use complete completion (<C-P> or <C-N> in insert mode.) By default, it matches all words in all buffers (even buffers that have been unloaded, i.e. files that have been closed), but is really fast. I found that the completion works quite accurately nonetheless, even if you activate it after 2-3 characters.