Vim's `findfile` function

I’ve recently updated the tests for stack.yaml and cabal.project files in my vim haskell plugin. The haskell#StackYamlFileExists and haskell#CabalProjectFileExists functions now take advantage of vim’s findfile function for searching up the directory tree, rather than just require that either file exist in the current working directory. This change makes a bit more sense given the way that both stack and cabal new-build work, allowing the commands to be invoked from anywhere underneath the directory that contains stack.yaml or cabal.project.

The findfile function is quite handy for this situation, as it’s able to search up as well as down the directory tree. Simply specifying the directory to search from as '.;' instructs it to search up the tree, and passing the {list} argument as -1 returns a list of the matches instead of the path of the first match.

I’ve now updated my personal haskell config to choose which tool to use, based on the three predicates that the plugin provides:

" Configure :make
if haskell#CabalProjectFileExists()
    compiler cabal-new-build
elseif haskell#StackYamlFileExists()
    compiler stack-build
elseif haskell#CabalFileExists()
    compiler cabal-build
endif