2a3b261 · haskell.nix · git.iko.soy

git.iko.soy/haskell.nix

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Adds desugar logic.

2a3b261Moritz Angermann8 years ago

new-package-set.nix+35−2

compare with iko/ghcjs-patch-master

unifiedsplit

@@ -23,14 +23,47 @@ in pkgs.lib.evalModules {

24 # Set the plan for modules/plan.nix

25 plan.pkg-def = hackage: with builtins;

26+ # The desugar reason.

27+ #

28+ # it is quite combersome to write

29+ # (hackage: { packages.x.revision = hackage...;

30+ # packages.y.revision = import ./foo.nix; })

31+ # where we'd rather write:

32+ # (hackage: { x = hackage...; })

33+ # or

34+ # { y = ./foo.nix; }

35+ # As such the desugarer desugars this short hand syntax.

36+ let desugar = overlay:

37+ let

38+ isPath = x: builtins.typeOf x == "path";

39+ # rewrite

40+ # { ... }

41+ # into

42+ # { package = { ... }; }

43+ inject-packages = o: if o ? "packages" then o else { packages = o; };

44+ # rewrite

45+ # x = pkg;

46+ # into

47+ # x.revision = pkg;

48+ inject-revision = pkg: if pkg ? "revision" then pkg else { revision = pkg; };

49+ # rewrite

50+ # x.revision = ./some/path;

51+ # into

52+ # x.revision = import ./some/path;

53+ expand-paths = pkg: if !(isPath pkg.revision) then pkg else { revision = import pkg.revision; };

54+ # apply injection and expansion to the "packages" in overlay.

55+ in lib.mapAttrs (k: v: if k != "packages"

56+ then v

57+ else lib.mapAttrs (_: pkg: (expand-paths (inject-revision pkg))) v)

58+ (inject-packages overlay);

26 # fold any potential `pkg-def-overlays`

59 # fold any potential `pkg-def-overlays`

27 # onto the `pkg-def`.

60 # onto the `pkg-def`.

28 #

61 #

29 # This means you can have a base definition (e.g. stackage)

62 # This means you can have a base definition (e.g. stackage)

30 # and augment it with custom packages to your liking.

63 # and augment it with custom packages to your liking.

31− foldl' lib.recursiveUpdate

64+ in foldl' lib.recursiveUpdate

32 (pkg-def hackage)

65 (pkg-def hackage)

33− (map (p: p hackage) pkg-def-overlays)

66+ (map (p: desugar (if builtins.isFunction p then p hackage else p)) pkg-def-overlays)

34 ;

67 ;

36 })

69 })