#+TITLE: Ocaml layer

[[file:img/ocaml.png]]

* Table of Content                                          :TOC_4_gh:noexport:
 - [[#description][Description]]
   - [[#features][Features:]]
 - [[#install][Install]]
   - [[#layer][Layer]]
   - [[#opam-packages][OPAM packages]]
 - [[#key-bindings][Key Bindings]]
   - [[#repl-utop][REPL (utop)]]
 - [[#todos][TODOS]]
   - [[#add-more-proper-spacemacs-key-bindings-for-basic-merlin-tasks][Add more proper spacemacs key-bindings for basic merlin tasks]]
   - [[#add-proper-keybindings-for-ocamldebug][Add proper keybindings for ocamldebug]]
   - [[#add-more-keybindings-for-tuareg-mode][Add more keybindings for tuareg-mode]]

* Description
This is a very basic layer for editing ocaml files.

** Features:
- Syntax highlighting (major-mode) via [[https://github.com/ocaml/tuareg][tuareg-mode]]
- Error reporting, completion and type display via [[https://github.com/the-lambda-church/merlin][merlin]]
- auto-completion with company mode via [[https://github.com/the-lambda-church/merlin][merlin]]
- syntax-checking via [[https://github.com/diml/utop][flycheck-ocaml]]

* Install
** Layer
To use this configuration layer, add it to your =~/.spacemacs=. You will need to
add =ocaml= to the existing =dotspacemacs-configuration-layers= list in this
file.

** OPAM packages
This layer requires some [[http://opam.ocaml.org][opam]] packages:

- =merlin= for auto-completion
- =utop=
- =ocp-indent=

To install them, use the following command:

#+BEGIN_SRC sh
  opam install merlin utop ocp-indent
#+END_SRC

Make sure opam is initialized and configured.

#+begin_src sh
  opam init
  opam config setup -a
#+end_src

* Key Bindings

| Key Binding | Description                                              |
|-------------+----------------------------------------------------------|
| ~SPC m =~   | Indent buffer.                                           |
| ~SPC m c c~ | Compile                                                  |
| ~SPC m c p~ | Check .merlin for errors                                 |
| ~SPC m c r~ | Refresh changed .cmis in merlin                          |
| ~SPC m e C~ | Check for errors in current buffer                       |
| ~SPC m e n~ | Jump to next error                                       |
| ~SPC m e N~ | Jump back to previous error                              |
| ~SPC m g a~ | Switch ML <-> MLI                                        |
| ~SPC m g b~ | Go back to the last position where the user did a locate |
| ~SPC m g g~ | Locate the identifier under point (same window)          |
| ~SPC m g G~ | Locate the identifier under point (different window)     |
| ~SPC m g o~ | List occurrences for identifier under point              |
| ~SPC m g l~ | Prompt for identifier and locate                         |
| ~SPC m g i~ | Prompt for module name and switch to ML file             |
| ~SPC m g I~ | Prompt for module name and switch to MLI file            |
| ~SPC m h h~ | Document the identifier under point                      |
| ~SPC m h t~ | Highlight identifier under cursor and print its type     |
| ~SPC m h T~ | Prompt for expression and show its type                  |
| ~SPC m r d~ | Case analyze the current enclosing                       |

** REPL (utop)

| Key Binding | Description                                                      |
|-------------+------------------------------------------------------------------|
| ~SPC m s b~ | Send buffer to the REPL                                          |
| ~SPC m s B~ | Send buffer to the REPL and switch to the REPL in =insert state= |
| ~SPC m s i~ | Start a REPL                                                     |
| ~SPC m s p~ | Send phrase to the REPL                                          |
| ~SPC m s P~ | Send phrase to the REPL and switch to the REPL in =insert state= |
| ~SPC m s r~ | Send region to the REPL                                          |
| ~SPC m s R~ | Send region to the REPL and switch to the REPL in =insert state= |
| ~C-j~       | (in REPL) next item in history                                   |
| ~C-k~       | (in REPL) previous item in history                               |

* TODOS

** TODO Add more proper spacemacs key-bindings for basic merlin tasks
** TODO Add proper keybindings for ocamldebug
** TODO Add more keybindings for tuareg-mode
