Merge pull request #32 from Second-Last/nixify

Add Nix flakes and development setup instructions

.gitignore

@@ -15,4 +15,6 @@ srcgen2/BUILD/JS
 srcgen2/xats2js/srcgen1/BUILD/JS
 srcgen2/xats2py/srcgen1/BUILD/JS
 
+result
+
 ###### end of [.gitignore] ######

DEVELOP.md

@@ -0,0 +1,30 @@
+This document provides instructions on how to setup your environment to
+develop/hack on ATS-Xanadu.
+
+## Prerequisites
+
+- The [`nix`](https://nixos.org/download/) package manager.
+
+That's it! The hard job of setting up dependencies and configuring environment
+variables are offloaded to Nix
+([flakes](https://zero-to-nix.com/concepts/flakes/)), all while making sure
+these changes are isolated for this project only and will not affect your
+system.
+
+## Steps
+
+> [!WARNING]
+> For advanced Make users: do **NOT** add `-j` flag to build in parallel. There
+are still issues regarding the way compiler outputs are merged together.
+The build is quick and shouldn't take more than 10 minutes to complete
+even when building with one core.
+
+1. Run `nix develop`. You will be dropped into a bash shell that contains all
+   the dependencies and environment variables configured for you.
+
+   The first run may take a while, because Nix needs to fetch dependencies.
+   Subsequent `nix develop` runs are much faster due to caching.
+
+2. Run `make -f Makefile_overall`.
+
+3. Now you have a working ATS3 compiler! Checkout the `PGROUND` for examples.

flake.nix

@@ -0,0 +1,31 @@
+{
+  description = "ATS-Xanadu";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { nixpkgs, flake-utils, self }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let 
+        pkgs = nixpkgs.legacyPackages.${system}; 
+      in
+      {
+        devShells = {
+          default = with pkgs; mkShell {
+            buildInputs = [
+              ats2
+              boehmgc
+              bun
+              nodejs
+            ];
+
+            shellHook = ''
+              export XATSHOME=$PWD
+            '';
+          };
+        };
+      }
+    );
+}

srcgen1/Makefile_patsopt

@@ -24,8 +24,10 @@ PATSOPT=$(PATSHOME)/bin/patsopt
 #
 NIXATS2=nix-shell -p ats2 --run
 #
+ifndef IN_NIX_SHELL
 PATSOPT=\
 nix --extra-experimental-features nix-command --extra-experimental-features flakes run github:githwxi/ATS-Postiats\#patsopt --
+endif
 ######
 #
 CFLAGS=

srcgen1/xats2js/srcgen1/Makefile_patsopt

@@ -23,8 +23,10 @@ PATSOPT=$(PATSHOME)/bin/patsopt
 #
 NIXATS2=nix-shell -p ats2 --run
 #
+ifndef IN_NIX_SHELL
 PATSOPT=\
 nix --extra-experimental-features nix-command --extra-experimental-features flakes run github:githwxi/ATS-Postiats\#patsopt --
+endif
 #
 ######
 #