A section of my vimrc for hy

gistfile1.txt

function! g:Refresh_hy_python_preview()
  redir => message
  redir END
  let pyfile = substitute(bufname("%"), ".hy", "", "") . ".generated.py"
  let errfile = substitute(bufname("%"), ".hy", "", "") . ".error"
  exec "silent !~/hy/bin/hy2py % > " . pyfile . " 2> " . errfile . " || cat " . errfile . " > " . pyfile
  call MyPreviewVSplit(pyfile)
  set nomodified
  "exec "silent !rm " . pyfile . " " . errfile
  redraw!
endfunction

function! MyPreviewVSplit( fname )
    let curbufnum=bufwinnr("%")
    let bufnum=bufnr(expand(a:fname))
    let winnum=bufwinnr(bufnum)
    if winnum != -1
        exe winnum . "wincmd w"
        e
    else
        " Make new split as usual
        exe "vsplit " . a:fname
    endif
    filetype detect
    exe curbufnum . "wincmd w"
endfunction

let g:autoHyPythonPreview = 0

function! g:ToggleAutoHyPythonPreview()
    if g:autoHyPythonPreview == 0
        "au BufWritePost *.hy call g:Refresh_hy_python_preview()
        au CursorHold *.hy call g:Refresh_hy_python_preview()
        au CursorHoldI *.hy call g:Refresh_hy_python_preview()
        echo "Hy -> Python preview turned on"
        set updatetime=500
        let g:autoHyPythonPreview = 1
    else
        "au! BufWritePost
        let g:autoHyPythonPreview = 0
        au! CursorHold
        au! CursorHoldI
        set updatetime=4000
        echo "Hy -> Python preview turned off"
    endif
endfunction

" Hack to use clojure filetype for hy
autocmd BufNewFile,BufRead *.hy set filetype=clojure
autocmd BufNewFile,BufRead *.hy map! <buffer> <F5> <Esc>:w<CR>:!hy % <CR>
autocmd BufNewFile,BufRead *.hy map  <buffer> <F5> <Esc>:w<CR>:!hy % <CR>
autocmd BufNewFile,BufRead *.hy map! <buffer> <F4> <Esc>:w<CR>:call g:Refresh_hy_python_preview()<CR>
autocmd BufNewFile,BufRead *.hy map  <buffer> <F4> <Esc>:w<CR>:call g:Refresh_hy_python_preview()<CR>
autocmd BufNewFile,BufRead *.hy map! <buffer> <F3> :call g:ToggleAutoHyPythonPreview()<CR>
autocmd BufNewFile,BufRead *.hy map  <buffer> <F3> :call g:ToggleAutoHyPythonPreview()<CR>