lib: Fix matchAttrs

This commit is contained in:
John Ericson 2017-04-01 15:34:38 -04:00
parent 2227789392
commit fffcee35f9

View file

@ -2,7 +2,7 @@
let
inherit (builtins) head tail length;
inherit (import ./trivial.nix) or;
inherit (import ./trivial.nix) and or;
inherit (import ./default.nix) fold;
inherit (import ./strings.nix) concatStringsSep;
inherit (import ./lists.nix) concatMap concatLists all deepSeqList;
@ -417,18 +417,15 @@ rec {
/* Returns true if the pattern is contained in the set. False otherwise.
FIXME(zimbatm): this example doesn't work !!!
Example:
sys = mkSystem { }
matchAttrs { cpu = { bits = 64; }; } sys
matchAttrs { cpu = {}; } { cpu = { bits = 64; }; }
=> true
*/
matchAttrs = pattern: attrs:
fold or false (attrValues (zipAttrsWithNames (attrNames pattern) (n: values:
matchAttrs = pattern: attrs: assert isAttrs pattern;
fold and true (attrValues (zipAttrsWithNames (attrNames pattern) (n: values:
let pat = head values; val = head (tail values); in
if length values == 1 then false
else if isAttrs pat then isAttrs val && matchAttrs head values
else if isAttrs pat then isAttrs val && matchAttrs pat val
else pat == val
) [pattern attrs]));