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lib/attrsets: add concatMapAttrs

This commit is contained in:
figsoda 2022-11-16 12:20:38 -05:00
parent 4536ebad69
commit f993f8a186
3 changed files with 38 additions and 2 deletions

View file

@ -3,7 +3,7 @@
let
inherit (builtins) head tail length;
inherit (lib.trivial) id;
inherit (lib.trivial) flip id mergeAttrs pipe;
inherit (lib.strings) concatStringsSep concatMapStringsSep escapeNixIdentifier sanitizeDerivationName;
inherit (lib.lists) foldr foldl' concatMap concatLists elemAt all partition groupBy take foldl;
in
@ -77,6 +77,25 @@ rec {
let errorMsg = "cannot find attribute `" + concatStringsSep "." attrPath + "'";
in attrByPath attrPath (abort errorMsg);
/* Map each attribute in the given set and merge them into a new attribute set.
Type:
concatMapAttrs ::
(String -> a -> AttrSet)
-> AttrSet
-> AttrSet
Example:
concatMapAttrs
(name: value: {
${name} = value;
${name + value} = value;
})
{ x = "a"; y = "b"; }
=> { x = "a"; xa = "a"; y = "b"; yb = "b"; }
*/
concatMapAttrs = f: flip pipe [ (mapAttrs f) attrValues (foldl' mergeAttrs { }) ];
/* Update or set specific paths of an attribute set.

View file

@ -78,7 +78,7 @@ let
inherit (self.attrsets) attrByPath hasAttrByPath setAttrByPath
getAttrFromPath attrVals attrValues getAttrs catAttrs filterAttrs
filterAttrsRecursive foldAttrs collect nameValuePair mapAttrs
mapAttrs' mapAttrsToList mapAttrsRecursive mapAttrsRecursiveCond
mapAttrs' mapAttrsToList concatMapAttrs mapAttrsRecursive mapAttrsRecursiveCond
genAttrs isDerivation toDerivation optionalAttrs
zipAttrsWithNames zipAttrsWith zipAttrs recursiveUpdateUntil
recursiveUpdate matchAttrs overrideExisting showAttrPath getOutput getBin

View file

@ -478,6 +478,23 @@ runTests {
# ATTRSETS
testConcatMapAttrs = {
expr = concatMapAttrs
(name: value: {
${name} = value;
${name + value} = value;
})
{
foo = "bar";
foobar = "baz";
};
expected = {
foo = "bar";
foobar = "baz";
foobarbaz = "baz";
};
};
# code from the example
testRecursiveUpdateUntil = {
expr = recursiveUpdateUntil (path: l: r: path == ["foo"]) {