From c8dbcea5a2175abe1e8684ff059491a30ab8836c Mon Sep 17 00:00:00 2001
From: Alp Mestanogullari <alpmestan@gmail.com>
Date: Sat, 2 Dec 2017 01:12:47 +0100
Subject: [PATCH] add shell.nix for building servant (+ tutorial + cookbook,
 optionally)

---
 .gitignore    |  2 --
 nix/README.md | 23 +++++++++++++++++++++++
 nix/shell.nix | 21 +++++++++++++++++++++
 3 files changed, 44 insertions(+), 2 deletions(-)
 create mode 100644 nix/README.md
 create mode 100644 nix/shell.nix

diff --git a/.gitignore b/.gitignore
index 16abfc41..98bf1884 100644
--- a/.gitignore
+++ b/.gitignore
@@ -25,8 +25,6 @@ cabal.config
 *.hp
 Setup
 .stack-work
-shell.nix
-default.nix
 doc/_build
 doc/venv
 doc/tutorial/static/api.js
diff --git a/nix/README.md b/nix/README.md
new file mode 100644
index 00000000..56400fbd
--- /dev/null
+++ b/nix/README.md
@@ -0,0 +1,23 @@
+You can use the `shell.nix` from this directory
+to build the servant packages or even the tutorial
+or cookbook if you want to, optionally.
+
+Just the servant packages:
+
+``` sh
+$ nix-shell nix/shell.nix
+```
+
+Everything needed for the tutorial and the
+cookbook too:
+
+``` sh
+$ nix-shell nix/shell.nix --arg tutorial true
+```
+
+The `shell.nix` file also supports specifying
+a particular ghc version, e.g:
+
+``` sh
+$ nix-shell nix/shell.nix --argstr compiler ghcHEAD
+```
diff --git a/nix/shell.nix b/nix/shell.nix
new file mode 100644
index 00000000..637aaeb2
--- /dev/null
+++ b/nix/shell.nix
@@ -0,0 +1,21 @@
+{ pkgs ? import <nixpkgs> {}
+, compiler ? "ghc821"
+, tutorial ? false
+}:
+
+with pkgs;
+
+let
+  ghc = haskell.packages.${compiler}.ghcWithPackages (_: []);
+  docstuffs = python3.withPackages (ps: with ps; [ recommonmark sphinx sphinx_rtd_theme ]);
+in
+
+stdenv.mkDerivation {
+    name = "servant-dev";
+    buildInputs = [ ghc zlib ]
+      ++ (if tutorial then [docstuffs postgresql] else []);
+    shellHook = ''
+      eval $(grep export ${ghc}/bin/ghc)
+      export LD_LIBRARY_PATH="${zlib}/lib";
+    '';
+}