From 7ed41ff5e7e633dd64866398ee497ac02736a3a5 Mon Sep 17 00:00:00 2001 From: Bas van Dijk Date: Tue, 7 Aug 2018 18:34:38 +0200 Subject: [PATCH] Revert "Remove types.functionTo." This reverts commit 4ff1ab5a56f1280d2de319ad4eb4b2796e07ed35. We need this to type options like: services.xserver.windowManager.xmonad.extraPackages that specify functions that take an attribute set containing packages / plugins and return a list containing a selection of the values in this set. The reason we need a dedicated type for this is to have the correct merge behaviour. Without the functionTo type merging multiple function option definitions results in an evaluation error. The functionTo type merges definitions by returning a new function that applies the functions of all the definitions to the given input and merges the result. --- lib/types.nix | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/lib/types.nix b/lib/types.nix index 4d6ac51c8988..46030dea7263 100644 --- a/lib/types.nix +++ b/lib/types.nix @@ -349,6 +349,16 @@ rec { functor = (defaultFunctor name) // { wrapped = elemType; }; }; + functionTo = elemType: mkOptionType { + name = "function that evaluates to a(n) ${elemType.name}"; + check = isFunction; + merge = loc: defs: + fnArgs: elemType.merge loc (map (fn: { inherit (fn) file; value = fn.value fnArgs; }) defs); + getSubOptions = elemType.getSubOptions; + getSubModules = elemType.getSubModules; + substSubModules = m: functionTo (elemType.substSubModules m); + }; + # A submodule (like typed attribute set). See NixOS manual. submodule = opts: let