idiosyn/lib/kernel.nix
2024-08-21 21:06:51 +02:00

59 lines
1.4 KiB
Nix

{ nixpkgs, ... }:
let
inherit (builtins)
isAttrs
isInt
length
match
toString;
inherit (nixpkgs.lib.asserts)
assertMsg;
inherit (nixpkgs.lib.attrsets)
isDerivation
mapAttrsToList
mergeAttrsList;
inherit (nixpkgs.lib.lists)
flatten;
inherit (nixpkgs.lib.strings)
concatStrings
concatStringsSep
escape;
isKey = str: match "[0-9A-Z][0-9A-Zx_]*" str != null;
isNum = str: match "(0x[0-9A-Fa-f]+|[1-9][0-9]*)" str != null;
mkValueString = v: let
v' = toString v;
in if v == true then "y"
else if isInt v || isNum v' then v'
else "\"${escape [ "\"" ] v'}\"";
in rec {
flattenAttrs = let
compose = p: n: if isKey n then p ++ [ n ] else p;
recurse = p: v:
if isValue v then { ${concatStringsSep "_" p} = v; }
else mapAttrsToList (n: v: recurse (compose p n) v) v;
in attrs: recurse [ ] attrs |> flatten |> mergeAttrsList;
option = v: { _option = v; };
isValue = x: isAttrs x -> !isDerivation x -> x ? _option;
isOptional = x: isAttrs x && !isDerivation x && x ? _option;
getValue = x: if isOptional x then x._option else x;
mkKey = n: assert isKey n; "CONFIG_${n}";
mkKeyValue = n: v: let
v' = getValue v;
in if (v' == false || v' == null)
then "# ${mkKey n} is not set"
else "${mkKey n}=${mkValueString v'}";
mkConfig = attrs: mapAttrsToList (k: v: mkKeyValue k v + "\n") attrs
|> concatStrings;
}