Nix flake support

.gitignore

@@ -23,3 +23,7 @@ erl_crash.dump
 pathex-*.tar
 
 /.elixir_ls/
+
+# Nix auto shell
+.direnv
+.envrc

flake.nix

@@ -0,0 +1,9 @@
+{
+  description = "Pathex: Elixir language lenses and Access replacement";
+  inputs.nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
+  outputs = { nixpkgs, ... }:
+    let pkgs = nixpkgs.legacyPackages.x86_64-linux;
+    in {
+      devShells.x86_64-linux.default = import ./shell.nix { inherit pkgs; };
+    };
+}

shell.nix

@@ -0,0 +1,30 @@
+{ pkgs ? (import <nixpkgs> { }), ... }:
+with pkgs;
+let otp = beam.packages.erlangR26;
+in pkgs.mkShell {
+  buildInputs = [
+    otp.elixir_1_16
+    otp.erlang
+    ((if otp ? elixir-ls then otp.elixir-ls else otp.elixir_ls).override {
+      elixir = otp.elixir_1_16;
+    })
+  ];
+
+  shellHook = ''
+    # keep your shell history in iex
+    export ERL_AFLAGS="-kernel shell_history enabled"
+
+    # Force UTF8 in CLI
+    export LANG="C.UTF-8"
+
+    # this isolates mix to work only in local directory
+    mkdir -p .nix-mix .nix-hex
+    export MIX_HOME=$PWD/.nix-mix
+    export HEX_HOME=$PWD/.nix-hex
+
+    # make hex from Nixpkgs available
+    # `mix local.hex` will install hex into MIX_HOME and should take precedence
+    export MIX_PATH="${otp.hex}/lib/erlang/lib/hex/ebin"
+    export PATH=$MIX_HOME/bin:$HEX_HOME/bin:$PATH
+  '';
+}