add dhall json

apparently this is not yet merged into dhall itself

.envrc

@@ -1 +0,0 @@
-eval "$(lorri direnv)"

default.nix

@@ -3,5 +3,7 @@
 {
   dhall-simple = import ./dhall-simple.nix { inherit pkgs; };
 
+  dhall-json-simple = import ./dhall-json-simple.nix { inherit pkgs; };
+
   dhall-bash-simple = import ./dhall-bash-simple.nix { inherit pkgs; };
 }

dhall-json-simple.nix

@@ -0,0 +1,24 @@
+{ pkgs ? import <nixpkgs> {} }:
+
+pkgs.stdenv.mkDerivation rec {
+  name = "dhall-json-simple";
+
+  src = if pkgs.stdenv.isDarwin
+    then pkgs.fetchurl {
+      url = "https://github.com/dhall-lang/dhall-haskell/releases/download/1.25.0/dhall-json-1.4.0-x86_64-macos.tar.bz2";
+      sha256 = "0427xy59mzyrz978l36x0ha610bpckg14m3svkvg8hipvblgh19r";
+    }
+    else pkgs.fetchurl {
+      url = "https://github.com/dhall-lang/dhall-haskell/releases/download/1.25.0/dhall-json-1.4.0-x86_64-linux.tar.bz2";
+      sha256 = "14apqq0dj3lmm8yccygf8bb27scxjfkjkmr8zgnwb98znr51gfwn";
+    };
+
+  installPhase = ''
+    mkdir -p $out/bin
+    DHALL_TO_JSON=$out/bin/dhall-to-json
+    install -D -m555 -T dhall-to-json $DHALL_TO_JSON
+
+    mkdir -p $out/etc/bash_completion.d/
+    $DHALL_TO_JSON --bash-completion-script $DHALL_TO_JSON > $out/etc/bash_completion.d/dhall-to-json-completion.bash
+  '';
+}

test.bash

@@ -15,6 +15,7 @@ function test_exe () {
 }
 
 test_exe dhall;
+test_exe dhall-to-json;
 test_exe dhall-to-bash;
 
 exit $ERRORS;