This checker executes the code in the files it checks. This is probably fine
if you wrote the files yourself, but it can be a problem if you're trying to
check third party files. If you are 100% willing to let Vim run the code in
your files, set g:enable_racket_racket_checker to 1 in your vimrc to enable
this checker: vim let g:enable_racket_racket_checker = 1 There is also a
buffer-local version of this variable, that takes precedence over it in the
buffers where it is defined.
Reference: https://github.com/scrooloose/syntastic/issues/1773
Error sorting can't be done as a postprocess function called from
SyntasticMake(), since the final values of some relevant fields (f.i.
type) might not be known yet at that point. Solution: move sorting to
getLocListRaw(), after per-checker quiet_messages. New checker methods
getWantSort() / setWantSort() are needed.
Second problem: some checkers return screen columns mixed with byte
indices. Solution: compute screen columns as needed. Sadly, everything
about working with screen columns is fragile.
