Unverified Commit e00a40a2 authored by Rick van Schijndel's avatar Rick van Schijndel Committed by GitHub
Browse files

Merge pull request #298680 from gvolpe/lib/transposeMap 

lib/attrsets: add mapCartesianProduct function
parents f8022afb 7b687a59

lib/attrsets.nix

+43 −5
Original line number Diff line number Diff line
@@ -5,7 +5,7 @@ 


let

  inherit (builtins) head length;

  inherit (lib.trivial) mergeAttrs warn;

  inherit (lib.trivial) isInOldestRelease mergeAttrs warn warnIf;

  inherit (lib.strings) concatStringsSep concatMapStringsSep escapeNixIdentifier sanitizeDerivationName;

  inherit (lib.lists) foldr foldl' concatMap elemAt all partition groupBy take foldl;

in
@@ -885,15 +885,15 @@ rec { 
    # Type



    ```

    cartesianProductOfSets :: AttrSet -> [AttrSet]

    cartesianProduct :: AttrSet -> [AttrSet]

    ```



    # Examples

    :::{.example}

    ## `lib.attrsets.cartesianProductOfSets` usage example

    ## `lib.attrsets.cartesianProduct` usage example



    ```nix

    cartesianProductOfSets { a = [ 1 2 ]; b = [ 10 20 ]; }

    cartesianProduct { a = [ 1 2 ]; b = [ 10 20 ]; }

    => [

         { a = 1; b = 10; }

         { a = 1; b = 20; }
@@ -904,7 +904,7 @@ rec { 


    :::

  */

  cartesianProductOfSets =

  cartesianProduct =

    attrsOfLists:

    foldl' (listOfAttrs: attrName:

      concatMap (attrs:
@@ -913,6 +913,40 @@ rec { 
    ) [{}] (attrNames attrsOfLists);





  /**

    Return the result of function f applied to the cartesian product of attribute set value combinations.

    Equivalent to using cartesianProduct followed by map.



    # Inputs



    `f`



    : A function, given an attribute set, it returns a new value.



    `attrsOfLists`



    : Attribute set with attributes that are lists of values



    # Type



    ```

    mapCartesianProduct :: (AttrSet -> a) -> AttrSet -> [a]

    ```



    # Examples

    :::{.example}

    ## `lib.attrsets.mapCartesianProduct` usage example



    ```nix

    mapCartesianProduct ({a, b}: "${a}-${b}") { a = [ "1" "2" ]; b = [ "3" "4" ]; }

    => [ "1-3" "1-4" "2-3" "2-4" ]

    ```



    :::



  */

  mapCartesianProduct = f: attrsOfLists: map f (cartesianProduct attrsOfLists);



  /**

    Utility function that creates a `{name, value}` pair as expected by `builtins.listToAttrs`.
@@ -1999,4 +2033,8 @@ rec { 
  # DEPRECATED

  zip = warn

    "lib.zip is a deprecated alias of lib.zipAttrsWith." zipAttrsWith;



  # DEPRECATED

  cartesianProductOfSets = warnIf (isInOldestRelease 2405)

    "lib.cartesianProductOfSets is a deprecated alias of lib.cartesianProduct." cartesianProduct;

}

lib/default.nix

+2 −2
Original line number Diff line number Diff line
@@ -86,8 +86,8 @@ let 
      zipAttrsWithNames zipAttrsWith zipAttrs recursiveUpdateUntil

      recursiveUpdate matchAttrs mergeAttrsList overrideExisting showAttrPath getOutput

      getBin getLib getDev getMan chooseDevOutputs zipWithNames zip

      recurseIntoAttrs dontRecurseIntoAttrs cartesianProductOfSets

      updateManyAttrsByPath;

      recurseIntoAttrs dontRecurseIntoAttrs cartesianProduct cartesianProductOfSets

      mapCartesianProduct updateManyAttrsByPath;

    inherit (self.lists) singleton forEach foldr fold foldl foldl' imap0 imap1

      concatMap flatten remove findSingle findFirst any all count

      optional optionals toList range replicate partition zipListsWith zipLists

lib/lists.nix

+19 −3
Original line number Diff line number Diff line
@@ -1692,12 +1692,28 @@ rec { 
    => [ "13" "14" "23" "24" ]

    ```



    The following function call is equivalent to the one deprecated above:



    ```nix

    mapCartesianProduct (x: "${toString x.a}${toString x.b}") { a = [1 2]; b = [3 4]; }

    => [ "13" "14" "23" "24" ]

    ```

    :::

  */

  crossLists = warn

    "lib.crossLists is deprecated, use lib.cartesianProductOfSets instead."

    (f: foldl (fs: args: concatMap (f: map f args) fs) [f]);

    ''lib.crossLists is deprecated, use lib.mapCartesianProduct instead.



    For example, the following function call:



    nix-repl> lib.crossLists (x: y: x+y) [[1 2] [3 4]]

    [ 4 5 5 6 ]



    Can now be replaced by the following one:



    nix-repl> lib.mapCartesianProduct ({x,y}: x+y) { x = [1 2]; y = [3 4]; }

    [ 4 5 5 6 ]

    ''

    (f: foldl (fs: args: concatMap (f: map f args) fs) [f]);



  /**

    Remove duplicate elements from the `list`. O(n^2) complexity.

lib/tests/misc.nix

+35 −15
Original line number Diff line number Diff line
@@ -33,7 +33,7 @@ let 
    boolToString

    callPackagesWith

    callPackageWith

    cartesianProductOfSets

    cartesianProduct

    cli

    composeExtensions

    composeManyExtensions
@@ -71,10 +71,10 @@ let 
    makeIncludePath

    makeOverridable

    mapAttrs

    mapCartesianProduct

    matchAttrs

    mergeAttrs

    meta

    mkOption

    mod

    nameValuePair

    optionalDrvAttr
@@ -117,7 +117,6 @@ let 
    expr = (builtins.tryEval expr).success;

    expected = true;

  };

  testingDeepThrow = expr: testingThrow (builtins.deepSeq expr expr);



  testSanitizeDerivationName = { name, expected }:

  let
@@ -1415,7 +1414,7 @@ runTests { 
    };



  testToPrettyMultiline = {

    expr = mapAttrs (const (generators.toPretty { })) rec {

    expr = mapAttrs (const (generators.toPretty { })) {

      list = [ 3 4 [ false ] ];

      attrs = { foo = null; bar.foo = "baz"; };

      newlinestring = "\n";
@@ -1429,7 +1428,7 @@ runTests { 
        there

        test'';

    };

    expected = rec {

    expected = {

      list = ''

        [

          3
@@ -1467,13 +1466,10 @@ runTests { 
    expected  = "«foo»";

  };



  testToPlist =

    let

      deriv = derivation { name = "test"; builder = "/bin/sh"; system = "aarch64-linux"; };

    in {

  testToPlist = {

    expr = mapAttrs (const (generators.toPlist { })) {

      value = {

        nested.values = rec {

        nested.values = {

          int = 42;

          float = 0.1337;

          bool = true;
@@ -1686,17 +1682,17 @@ runTests { 
  };



  testCartesianProductOfEmptySet = {

    expr = cartesianProductOfSets {};

    expr = cartesianProduct {};

    expected = [ {} ];

  };



  testCartesianProductOfOneSet = {

    expr = cartesianProductOfSets { a = [ 1 2 3 ]; };

    expr = cartesianProduct { a = [ 1 2 3 ]; };

    expected = [ { a = 1; } { a = 2; } { a = 3; } ];

  };



  testCartesianProductOfTwoSets = {

    expr = cartesianProductOfSets { a = [ 1 ]; b = [ 10 20 ]; };

    expr = cartesianProduct { a = [ 1 ]; b = [ 10 20 ]; };

    expected = [

      { a = 1; b = 10; }

      { a = 1; b = 20; }
@@ -1704,12 +1700,12 @@ runTests { 
  };



  testCartesianProductOfTwoSetsWithOneEmpty = {

    expr = cartesianProductOfSets { a = [ ]; b = [ 10 20 ]; };

    expr = cartesianProduct { a = [ ]; b = [ 10 20 ]; };

    expected = [ ];

  };



  testCartesianProductOfThreeSets = {

    expr = cartesianProductOfSets {

    expr = cartesianProduct {

      a = [   1   2   3 ];

      b = [  10  20  30 ];

      c = [ 100 200 300 ];
@@ -1753,6 +1749,30 @@ runTests { 
    ];

  };



  testMapCartesianProductOfOneSet = {

    expr = mapCartesianProduct ({a}: a * 2) { a = [ 1 2 3 ]; };

    expected = [ 2 4 6 ];

  };



  testMapCartesianProductOfTwoSets = {

    expr = mapCartesianProduct ({a,b}: a + b) { a = [ 1 ]; b = [ 10 20 ]; };

    expected = [ 11 21 ];

  };



  testMapCartesianProcutOfTwoSetsWithOneEmpty = {

    expr = mapCartesianProduct (x: x.a + x.b) { a = [ ]; b = [ 10 20 ]; };

    expected = [ ];

  };



  testMapCartesianProductOfThreeSets = {

    expr = mapCartesianProduct ({a,b,c}: a + b + c) {

      a = [ 1 2 3 ];

      b = [ 10 20 30 ];

      c = [ 100 200 300 ];

    };

    expected = [ 111 211 311 121 221 321 131 231 331 112 212 312 122 222 322 132 232 332 113 213 313 123 223 323 133 233 333 ];

  };



  # The example from the showAttrPath documentation

  testShowAttrPathExample = {

    expr = showAttrPath [ "foo" "10" "bar" ];

nixos/modules/services/x11/display-managers/default.nix

+2 −2
Original line number Diff line number Diff line
@@ -284,7 +284,7 @@ in 
      in

        # We will generate every possible pair of WM and DM.

        concatLists (

            builtins.map

            lib.mapCartesianProduct

            ({dm, wm}: let

              sessionName = "${dm.name}${optionalString (wm.name != "none") ("+" + wm.name)}";

              script = xsession dm wm;
@@ -312,7 +312,7 @@ in 
                  providedSessions = [ sessionName ];

                })

            )

            (cartesianProductOfSets { dm = dms; wm = wms; })

            { dm = dms; wm = wms; }

          );

  };