The built-in indenting in Vim for OCaml seems not very good. How to set up auto indenting for OCaml code in Vim? ocp-indent works very well for me. This posts introduces how to configure Vim to use ocp-indent to automatically indent/format OCaml code.
First, install ocp-indent after installing opam:
$ opam install ocp-indentSecond, configure vim by adding these lines to your ~/.vimrc:
au BufEnter *.ml setf ocaml
au BufEnter *.mli setf ocaml
au FileType ocaml call FT_ocaml()
function FT_ocaml()
set textwidth=80
set colorcolumn=80
set shiftwidth=2
set tabstop=2
" ocp-indent with ocp-indent-vim
let opamshare=system("opam config var share | tr -d '\n'")
execute "autocmd FileType ocaml source".opamshare."/vim/syntax/ocp-indent.vim"
filetype indent on
filetype plugin indent on
endfunctionYou can use == to format the code selected or the current line now.
Third, to make ocp-indent be automatically invoked by autoindent, add the ocp-indent-vim script. This ensures that ocp-indent will indent the current line after you input Enter, “if”, “else”, etc. You can use tools like pathogen to manage the installed plugins in Vim.
Last, configuring the ocp-indent by adding these lines to ~/.ocp/ocp-indent.conf":
# These are `normal`, `apprentice` and `JaneStreet` and set different defaults.
JaneStreetYou may choose the other defaults. The JaneStreet mode works great for me.
Update: newer version of `ocp-indent` changes the location of the ocp-indent.vim script. Updated the .vimrc config to reflect this change.
Hello, Could you explain the third part in more detail? Specifically:
(* I’m not clear on what the significance of this instruction is *)
“You can use == to format the code selected or the current line now.”
(* how do you “add” the script? *)
“Third, to make ocp-indent be automatically invoked by autoindent, add the ocp-indent-vim script. This ensures that ocp-indent will indent the current line after you input Enter, “if”, “else”, etc. You can use tools like pathogen to manage the installed plugins in Vim.”
Kindly,
John
> About “You can use == to format the code selected or the current line now.”
Pressing `=` twice in command mode will make Vim help us indent the code (if it was not indented correctly).
> About “add”ing the script:
Pathogen is a Vim plugin manager. Now with latest Vim, I suggest to use Vim’s built-in package management instead: `:help packages`.