Initialize Repo

Working (but likely buggy!) lexing, parsing, and evaluation of Tree Calculus terms

flake.nix

@@ -0,0 +1,66 @@
+{
+  description = "sapling";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs              = nixpkgs.legacyPackages.${system};
+        packageName       = "sapling";
+        containerPackageName = "${packageName}-container";
+
+        customGHC = pkgs.haskellPackages.ghcWithPackages (hpkgs: with hpkgs; [
+          megaparsec
+        ]);
+
+        haskellPackages = pkgs.haskellPackages;
+
+        enableSharedExecutables = false;
+        enableSharedLibraries = false;
+
+        sapling = pkgs.haskell.lib.justStaticExecutables self.packages.${system}.default;
+      in {
+
+        packages.${packageName} =
+          haskellPackages.callCabal2nix packageName self rec {};
+
+        packages.default = self.packages.${system}.${packageName};
+        defaultPackage = self.packages.${system}.default;
+
+        devShells.default = pkgs.mkShell {
+          buildInputs = with pkgs.haskellPackages; [
+            cabal-install
+            ghcid
+            customGHC
+          ];
+          inputsFrom = builtins.attrValues self.packages.${system};
+        };
+        devShell = self.devShells.${system}.default;
+
+        packages.${containerPackageName} = pkgs.dockerTools.buildImage {
+          name = "sapling";
+
+          copyToRoot = pkgs.buildEnv {
+            name = "image-root";
+            paths = [ sapling ];
+            pathsToLink = [ "/bin" ];
+          };
+          tag = "latest";
+          config = {
+            Cmd = [
+              "/bin/sapling"
+            ];
+            WorkingDir = "/app";
+            ExposedPorts = {
+              "3000/tcp" = {};
+            };
+            extraCommands = ''
+            '';
+          };
+        };
+      });
+}