Centralize hackage packages to deps.nix

This also allowes me to make 'repl' into a universal command. This makes
it much easier to work across different projects.

1 files changed, 18 insertions, 5 deletions

diff --git a/biz.nix b/biz.nix
index 1194758..576d3c4 100644
--- a/biz.nix
+++ b/biz.nix
@@ -9,22 +9,33 @@ let
 
   # general functions to put in a lib
   lines = s: strings.splitString "\n" s;
-  seq = ls: builtins.filter (x: x!= null) ls;
+  removeNull = ls: builtins.filter (x: x != null) ls;
+
   depsToPackageSet = packageSet: deps:
-    map (s: builtins.getAttr s packageSet) deps;
+    attrsets.attrVals deps packageSet;
+
+  # returns true if a is a subset of b, where a and b are attrsets
+  subset = a: b: builtins.all
+    (x: builtins.elem x b) a;
+
+  allDeps = import ./deps.nix;
 in {
   buildGhc = main:
     let
       relpath = builtins.replaceStrings ["${root}/"] [""] (builtins.toString main);
       module = builtins.replaceStrings ["/" ".hs"] ["." ""] relpath;
       content = builtins.readFile main;
-      exe = builtins.head (lists.flatten (seq
+      exe = builtins.head (lists.flatten (removeNull
         (map (builtins.match "^-- : exe ([[:alnum:]._-]*)$")
           (lines content))));
-      deps = lists.flatten (seq
+      deps = lists.flatten (removeNull
         (map (builtins.match "^-- : dep ([[:alnum:]._-]*)$")
           (lines content)));
-      ghc = pkgs.haskell.packages.ghc865.ghcWithHoogle (hp: depsToPackageSet hp deps);
+      ghc = pkgs.haskell.packages.ghc865.ghcWithHoogle (hp:
+          if (subset deps allDeps)
+          then depsToPackageSet hp deps
+          else throw ("missing from deps.nix: ${toString (lib.lists.subtractLists allDeps deps)}")
+      );
     in stdenv.mkDerivation {
       name = module;
       version = "0";
@@ -82,4 +93,6 @@ in {
       '';
       installPhase = "exit 0";
     } // { env = ghcjs; };
+
+  globalGhc = pkgs.haskell.packages.ghc865.ghcWithHoogle (hp: depsToPackageSet hp allDeps);
 }