fix priority ranking

[haoxianhan]

if _build dir is exist, other such as apps tags' priority would less-than _build's, but it don't want to jump _build in general, so hard code _build priority to be lower. it's hotfix for me, clean up the code if necessary.

[hcs42]

Hi @haoxianhan,

Thank you for your contribution.

I modified your commit: https://github.com/hcs42/vim-erlang-tags/commits/build_dir_priority

• I made sure that the code conforms to https://github.com/vim-erlang/vim-erlang#contributing. (Every new function has a docstring and a typespec, the lines are not longer than 80 characters, etc).
• I added automatic tests (see https://github.com/hcs42/vim-erlang/commits/build_dir_priority)
• I removed the temporary ETS table (and instead modified the code to the perform sorting on the Erlang representation of the tags, rather than the binary output lines).
• Previously your fix worked only if you were in the same directory where the _build directory was (because of the string:prefix call). The modified commit recognizes _build directories even if you are not in its parent directory.
• My other reason for replacing string:prefix with re:run is that string:prefix was introduced in OTP 20, and I would like to keep vim-erlang working with older Erlang versions. (E.g., it even works on OTP R16B03.)

Could you test the modified commit?

Out of curiosity: do you use Windows?

[haoxianhan]

wow, my pleasure, I would test this branch these days. I use is archlinux for my dev environment, ssh remote by win10.

[haoxianhan]

I use the build_dir_priority branch for few days, it works fine. Furthermore, I've compared the build_dir_priority's tags to my hotfix's, build_dir_priority's more appropriate.

[hcs42]

I merged the commits.