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author | Alyssa Ross <hi@alyssa.is> | 2021-08-04 10:43:07 +0000 |
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committer | Alyssa Ross <hi@alyssa.is> | 2021-08-04 10:43:07 +0000 |
commit | 62614cbef7da005c1eda8c9400160f6bcd6546b8 (patch) | |
tree | c2630f69080637987b68acb1ee8676d2681fe304 /lib/fixed-points.nix | |
parent | d9c82ed3044c72cecf01c6ea042489d30914577c (diff) | |
parent | e24069138dfec3ef94f211f1da005bb5395adc11 (diff) | |
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Merge branch 'nixpkgs-update' into master
Diffstat (limited to 'lib/fixed-points.nix')
-rw-r--r-- | lib/fixed-points.nix | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/lib/fixed-points.nix b/lib/fixed-points.nix index 968930526a6..f998bc74e1d 100644 --- a/lib/fixed-points.nix +++ b/lib/fixed-points.nix @@ -1,4 +1,4 @@ -{ ... }: +{ lib, ... }: rec { # Compute the fixed point of the given function `f`, which is usually an # attribute set that expects its final, non-recursive representation as an @@ -77,6 +77,15 @@ rec { super' = super // fApplied; in fApplied // g self super'; + # Compose several extending functions of the type expected by 'extends' into + # one where changes made in preceding functions are made available to + # subsequent ones. + # + # composeManyExtensions : [packageSet -> packageSet -> packageSet] -> packageSet -> packageSet -> packageSet + # ^final ^prev ^overrides ^final ^prev ^overrides + composeManyExtensions = + lib.foldr (x: y: composeExtensions x y) (self: super: {}); + # Create an overridable, recursive attribute set. For example: # # nix-repl> obj = makeExtensible (self: { }) |