Merge pull request #72 from akirak/ocaml

Add OCaml

.github/workflows/check-ocaml.yml

@@ -0,0 +1,47 @@
+name: Check ocaml
+
+on:
+  push:
+    paths:
+      # Set this to the directory of the template
+      - ocaml/**
+      - .github/workflows/check-ocaml.yml
+  workflow_dispatch:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: cachix/install-nix-action@v25
+        with:
+          extra_nix_config: |
+            access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
+
+      - uses: actions/checkout@v4
+        with:
+          path: ./tmp
+
+      - name: Initialize a Dune project
+        run: |
+          nix run nixpkgs#dune_3 -- init project hello work
+
+      - name: Use the template
+        run: |
+          nix flake new -t ./tmp#ocaml work
+
+      - name: Prepare the project
+        working-directory: work
+        run: |
+          sed -i 's/throw "Name your OCaml package"/"hello"/' flake.nix
+          sed -i 's/throw "Version your OCaml package"/"0.1"/' flake.nix
+          git init
+          git add .
+
+      - name: Check executables
+        run: |
+          nix develop -L --command ocamlc --version
+        working-directory: work

README.md

@@ -78,6 +78,25 @@ after initialization, e.g. to use yarn instead of pnpm.
 It uses the master branch of NixPkgs to install a recent set of node
 packages.
 
+### [ocaml](ocaml/)
+
+This flake.nix lets you use [Dune](https://dune.build/) for your development
+workflow but also allows to build your package using Nix.
+It depends on [the overlay from
+nix-ocaml](https://github.com/nix-ocaml/nix-overlays).
+
+``` bash
+nix flake init -t github:akirak/flake-templates#ocaml
+```
+
+You will define your OCaml dependencies in `propagatedBuildInputs` of the dune
+package in `flake.nix`. With the `direnv` integration, you don't have to
+manually install packages using `opam` for development.
+
+See also [the Nixpkgs
+manual](https://nixos.org/manual/nixpkgs/unstable/#sec-language-ocaml) for
+concrete information.
+
 ### [rust](rust/)
 
 This flake.nix provides a Rust toolchain.

flake.nix

@@ -27,6 +27,10 @@
         path = ./node-typescript;
         description = "Toolchain for TypeScript frontend projects";
       };
+      ocaml = {
+        path = ./ocaml;
+        description = "A flake template for development with OPAM and Dune";
+      };
       rust = {
         path = ./rust;
         description = "Rust toolchain";

ocaml/.envrc

@@ -0,0 +1,5 @@
+use flake
+
+# Using _build directory may not be properly allowed for storing user contents
+export ODIG_CACHE_DIR="$(pwd)/_build/default/.odig"
+export SHERLODOC_DB="$(pwd)/_build/default/.sherlodoc.marshal"

ocaml/.gitignore

@@ -0,0 +1 @@
+_build

ocaml/.ocamlformat

@@ -0,0 +1,12 @@
+# Latest version is available from
+# https://github.com/ocaml-ppx/ocamlformat/blob/main/.ocamlformat
+
+profile = ocamlformat
+break-cases = fit
+margin = 77
+wrap-comments = true
+line-endings = lf
+
+# To make ocaml-ci happy
+version = ignore
+version-check = false

ocaml/flake.nix

@@ -0,0 +1,96 @@
+{
+  inputs = {
+    # nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+    systems.url = "github:nix-systems/default";
+
+    ocaml-overlays.url = "github:nix-ocaml/nix-overlays";
+    ocaml-overlays.inputs.nixpkgs.follows = "nixpkgs";
+  };
+
+  outputs = {
+    self,
+    systems,
+    nixpkgs,
+    ocaml-overlays,
+    ...
+  } @ inputs: let
+    inherit (nixpkgs) lib;
+
+    eachSystem = f:
+      nixpkgs.lib.genAttrs (import systems) (
+        system: let
+          pkgs = import nixpkgs {
+            inherit system;
+            overlays = [ocaml-overlays.overlays.default];
+          };
+        in
+          f
+          {
+            inherit pkgs system;
+            ocamlPackages = pkgs.ocaml-ng.ocamlPackages_latest;
+          }
+      );
+  in {
+    ocamlPackages = eachSystem ({ocamlPackages, ...}: ocamlPackages);
+
+    packages = eachSystem ({
+      pkgs,
+      ocamlPackages,
+      ...
+    }: {
+      default = ocamlPackages.buildDunePackage {
+        pname = throw "Name your OCaml package";
+        version = throw "Version your OCaml package";
+        duneVersion = "3";
+        src = self.outPath;
+
+        # Uncomment if you need the executable of dream_eml during build
+        # preBuild = ''
+        #   PATH="${ocamlPackages.dream}/bin:$PATH"
+        #   export PATH
+        # '';
+
+        buildInputs = with ocamlPackages; [
+          ocaml-syntax-shims
+        ];
+
+        propagatedBuildInputs = with ocamlPackages; [
+          # Add OCaml dependencies required for your project
+
+          # Jane Street
+          base
+          core
+          core_unix
+
+          # Some common dependencies
+          # eio
+          # eio_main
+          # yojson
+          # ppx_yojson_conv
+        ];
+      };
+    });
+
+    devShells = eachSystem ({
+      pkgs,
+      ocamlPackages,
+      ...
+    }: {
+      default = pkgs.mkShell {
+        inputsFrom = [self.packages.${pkgs.system}.default];
+        buildInputs =
+          lib.optional pkgs.stdenv.isLinux pkgs.inotify-tools
+          ++ (with ocamlPackages; [
+            ocaml-lsp
+            ocamlformat
+            ocp-indent
+            utop
+            # Needed for generating documentation
+            opam
+            odoc
+            odig
+          ]);
+      };
+    });
+  };
+}

ocaml/justfile

@@ -0,0 +1,7 @@
+odig-odoc:
+    odig odoc
+
+sherlodoc-index: odig-odoc
+    find "$(odig cache path)/odoc" -name '*.odocl' \
+    | grep -v '__' \
+    | xargs sherlodoc index