vim-reasonml:

Native Reason development with esy and Merlin

vim-reasonml provides vim IDE features for native Reason projects that use esy and merlin.

Features:

Automatically loads Merlin plugin from your esy devDependencies.
Merlin autocomplete, goto-location, type-at-cursor features (provided by merlin)
Airline integration for esy projects and compilation errors.
:ReasonPrettyPrint with enhanced syntax error locations.
Reason syntax highlighting and Dune build config syntax highlighting.
Highlighting of esy #{build variables} in .json files.
Preliminary Windows support with esy Windows.

See The vim-reasonml Plugin Documentation.

Install

npm install -g esy
Install vim-reasonml with your vim plugin manager. If using vim-plug add Plug 'jordwalke/vim-reasonml' to your ~/.vimrc)
Create a project with @opam/merlin as a devDependency. You can fork hello-reason to get started.
esy install && esy build as you normally would.
Open a .re file from the project in Vim.

Formatting

The command :ReasonPrettyPrint invokes the binary refmt which must be available on your PATH. Add a keyboard mapping shortcut like this:

autocmd FileType reason map <buffer> <D-C> :ReasonPrettyPrint<Cr>

Error/Warning Highlighting:

To enable syntastic support, add the following to your ~/.vimrc:

" If using vim-plug, install syntastic:
Plug 'scrooloose/syntastic'

Neomake support can be enabled by setting let g:neomake_reason_enabled_makers = ['merlin'].

Merlin

Merlin is supported out of the box by pulling merlin from your devDependencies. You will need to install an autocomplete plugin to get natural complete-as-you-type behavior. For example to install mucomplete, using vim-plug, add the following config:

" If using vim-plug, install mucomplete:
Plug 'lifepillar/vim-mucomplete'
let g:mucomplete#can_complete = {}
let g:mucomplete#enable_auto_at_startup = 1
let g:mucomplete#chains = {'default': ['omni']}

Airline Integration

vim-reasonml includes an airline extension which show the project name of the current file (and project status) in an airline segment. Another included extension shows the current number of syntastic errors and warnings.

" Airline: Enable the airline extensions for esy project status and reason
" syntastic plugin.
let g:airline_extensions = ['esy', 'reason']
let g:reasonml_project_airline=1
let g:reasonml_syntastic_airline=1
let g:reasonml_clean_project_airline=1
let g:airline#extensions#whitespace#enabled = 0
let g:airline_powerline_fonts = 1
let g:airline_skip_empty_sections = 1

LICENSE

Some files from vim-reasonml are based on the Rust vim plugin and so we are including that license.

jordwalke/vim-reasonml