vimrc.d/paths.vim

Enforce vim script implementation to reduce ambiguities and improve robustness:

scriptversion 4

Find XDG base directory specification compliant locations for data files:

for [s:type, s:path] in [
\   ['cache', '~/.cache'],
\   ['config', '~/.config'],
\   ['data', '~/.local/share'],
\ ]
    let s:envvar = printf('$XDG_%s_HOME', toupper(s:type))
    const g:xdg_{s:type}_dir = expand(exists(s:envvar) ? s:envvar : s:path)
endfor

vim specific paths honouring XDG base directory specification:

for s:name in ['cache', 'config', 'data']
    const g:vim_{s:name}_dir = g:xdg_{s:name}_dir .. '/vim'
    if !isdirectory(g:vim_{s:name}_dir)
        call mkdir(g:vim_{s:name}_dir, 'p')
    endif
endfor