melange-basic-template

A simple project template using Melange.

Getting started

You will need esy package manager to obtain OCaml and Melange sources. See esy installation instructions here.

Once esy is available, run

esy

to install all dependencies.

Then:

esy build

to build the project. This command, as constructed in esy.json,

1. generates a symbolically linked dir bs-platform in node_modules, which is helpful when using JavaScript bundlers like Webpack that expect to find Melange stdlib JavaScript files under node_modules/bs-platform.
2. builds the project.

Now you should see a _build folder with all generated files, you can run

esy x node _build/default/src/Main.bs.js

to see the result of the script running.

Editor support in VSCode

Using these dependencies

  "dependencies": {
    "ocaml": "4.14.0",
    "@opam/reason": "3.8.0",
    "@opam/dot-merlin-reader": "4.2",
    "melange": "melange-re/melange",
    "@opam/cmdliner": "1.1.0",
    "@opam/ocaml-lsp-server": "ocaml/ocaml-lsp:ocaml-lsp-server.opam#196ad28"
  },

Select esy(melange-editor-support) as your sandbox.

You still get errors in the your file. If you use opam(4.14.0) directly as sandbox you dont get errors.

Solution per @zecklar

1. Install OCaml plugin https://marketplace.visualstudio.com/items?itemName=ocamllabs.ocaml-platform
2. Build your project esy build
3. Launch VSCode in your esy dev environment `esy code .`
4. On the lefthand side, click OCaml extension icon
5. Click "Select sandbox"
6. Select "Custom" from the dropdown
7. Pass the flag, the input box should contain `$prog $args --fallback-read-dot-merlin`
8. Voila, at least typehints/navigation etc seem to work