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lib.overrideExisting: Better example

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Silvan Mosberger 2018-09-17 23:28:47 +02:00
parent afd8620621
commit c7104d97c8
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1 changed files with 6 additions and 3 deletions
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lib/attrsets.nix
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@ -435,9 +435,12 @@ rec {
useful for deep-overriding.
Example:
x = { a = { b = 4; c = 3; }; }
overrideExisting x { a = { b = 6; d = 2; }; }
=> { a = { b = 6; d = 2; }; }
overrideExisting {} { a = 1; }
=> {}
overrideExisting { b = 2; } { a = 1; }
=> { b = 2; }
overrideExisting { a = 3; b = 2; } { a = 1; }
=> { a = 1; b = 2; }
*/
overrideExisting = old: new:
mapAttrs (name: value: new.${name} or value) old;