diff options
Diffstat (limited to 'lib')
-rw-r--r-- | lib/attrsets.nix | 19 | ||||
-rw-r--r-- | lib/default.nix | 2 | ||||
-rw-r--r-- | lib/lists.nix | 4 | ||||
-rw-r--r-- | lib/tests/misc.nix | 67 |
4 files changed, 89 insertions, 3 deletions
diff --git a/lib/attrsets.nix b/lib/attrsets.nix index d91d7a0cd47e6..0ce3aaeca452d 100644 --- a/lib/attrsets.nix +++ b/lib/attrsets.nix @@ -183,6 +183,24 @@ rec { else []; + /* Return the cartesian product of attribute set value combinations. + + Example: + cartesianProductOfSets { a = [ 1 2 ]; b = [ 10 20 ]; } + => [ + { a = 1; b = 10; } + { a = 1; b = 20; } + { a = 2; b = 10; } + { a = 2; b = 20; } + ] + */ + cartesianProductOfSets = attrsOfLists: + lib.foldl' (listOfAttrs: attrName: + concatMap (attrs: + map (listValue: attrs // { ${attrName} = listValue; }) attrsOfLists.${attrName} + ) listOfAttrs + ) [{}] (attrNames attrsOfLists); + /* Utility function that creates a {name, value} pair as expected by builtins.listToAttrs. @@ -493,5 +511,4 @@ rec { zipWithNames = zipAttrsWithNames; zip = builtins.trace "lib.zip is deprecated, use lib.zipAttrsWith instead" zipAttrsWith; - } diff --git a/lib/default.nix b/lib/default.nix index 803f1f765647e..50320669e2804 100644 --- a/lib/default.nix +++ b/lib/default.nix @@ -78,7 +78,7 @@ let zipAttrsWithNames zipAttrsWith zipAttrs recursiveUpdateUntil recursiveUpdate matchAttrs overrideExisting getOutput getBin getLib getDev getMan chooseDevOutputs zipWithNames zip - recurseIntoAttrs dontRecurseIntoAttrs; + recurseIntoAttrs dontRecurseIntoAttrs cartesianProductOfSets; inherit (self.lists) singleton forEach foldr fold foldl foldl' imap0 imap1 concatMap flatten remove findSingle findFirst any all count optional optionals toList range partition zipListsWith zipLists diff --git a/lib/lists.nix b/lib/lists.nix index 06cee2eb112ab..56af4d9daa186 100644 --- a/lib/lists.nix +++ b/lib/lists.nix @@ -629,7 +629,9 @@ rec { crossLists (x:y: "${toString x}${toString y}") [[1 2] [3 4]] => [ "13" "14" "23" "24" ] */ - crossLists = f: foldl (fs: args: concatMap (f: map f args) fs) [f]; + crossLists = builtins.trace + "lib.crossLists is deprecated, use lib.cartesianProductOfSets instead" + (f: foldl (fs: args: concatMap (f: map f args) fs) [f]); /* Remove duplicate elements from the list. O(n^2) complexity. diff --git a/lib/tests/misc.nix b/lib/tests/misc.nix index 35a5801c724fe..0d249968402d9 100644 --- a/lib/tests/misc.nix +++ b/lib/tests/misc.nix @@ -660,4 +660,71 @@ runTests { expected = [ [ "foo" ] [ "foo" "<name>" "bar" ] [ "foo" "bar" ] ]; }; + testCartesianProductOfEmptySet = { + expr = cartesianProductOfSets {}; + expected = [ {} ]; + }; + + testCartesianProductOfOneSet = { + expr = cartesianProductOfSets { a = [ 1 2 3 ]; }; + expected = [ { a = 1; } { a = 2; } { a = 3; } ]; + }; + + testCartesianProductOfTwoSets = { + expr = cartesianProductOfSets { a = [ 1 ]; b = [ 10 20 ]; }; + expected = [ + { a = 1; b = 10; } + { a = 1; b = 20; } + ]; + }; + + testCartesianProductOfTwoSetsWithOneEmpty = { + expr = cartesianProductOfSets { a = [ ]; b = [ 10 20 ]; }; + expected = [ ]; + }; + + testCartesianProductOfThreeSets = { + expr = cartesianProductOfSets { + a = [ 1 2 3 ]; + b = [ 10 20 30 ]; + c = [ 100 200 300 ]; + }; + expected = [ + { a = 1; b = 10; c = 100; } + { a = 1; b = 10; c = 200; } + { a = 1; b = 10; c = 300; } + + { a = 1; b = 20; c = 100; } + { a = 1; b = 20; c = 200; } + { a = 1; b = 20; c = 300; } + + { a = 1; b = 30; c = 100; } + { a = 1; b = 30; c = 200; } + { a = 1; b = 30; c = 300; } + + { a = 2; b = 10; c = 100; } + { a = 2; b = 10; c = 200; } + { a = 2; b = 10; c = 300; } + + { a = 2; b = 20; c = 100; } + { a = 2; b = 20; c = 200; } + { a = 2; b = 20; c = 300; } + + { a = 2; b = 30; c = 100; } + { a = 2; b = 30; c = 200; } + { a = 2; b = 30; c = 300; } + + { a = 3; b = 10; c = 100; } + { a = 3; b = 10; c = 200; } + { a = 3; b = 10; c = 300; } + + { a = 3; b = 20; c = 100; } + { a = 3; b = 20; c = 200; } + { a = 3; b = 20; c = 300; } + + { a = 3; b = 30; c = 100; } + { a = 3; b = 30; c = 200; } + { a = 3; b = 30; c = 300; } + ]; + }; } |