lib: add xor

This gets clumsily reimplemented in various places, to no useful end.
NixOS · Apr 4, 2024 · 7c923db · 7c923db
1 parent d03a448
commit 7c923db
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Showing 12 changed files with 44 additions and 38 deletions.
diff --git a/lib/default.nix b/lib/default.nix
@@ -69,7 +69,7 @@ let
  hasAttr head isAttrs isBool isInt isList isPath isString length
  lessThan listToAttrs pathExists readFile replaceStrings seq
  stringLength sub substring tail trace;
- inherit (self.trivial) id const pipe concat or and bitAnd bitOr bitXor
+ inherit (self.trivial) id const pipe concat or and xor bitAnd bitOr bitXor
  bitNot boolToString mergeAttrs flip mapNullable inNixShell isFloat min max
  importJSON importTOML warn warnIf warnIfNot throwIf throwIfNot checkListOfEnum
  info showWarnings nixpkgsVersion version isInOldestRelease

diff --git a/lib/tests/misc.nix b/lib/tests/misc.nix
@@ -102,6 +102,7 @@ let
  types
  updateManyAttrsByPath
  versions
+ xor
  ;
 
  testingThrow = expr: {
@@ -210,6 +211,16 @@ runTests {
  expected = false;
  };
 
+ testXorTrue = {
+ expr = xor true false;
+ expected = true;
+ };
+
+ testXorFalse = {
+ expr = xor true true;
+ expected = false;
+ };
+
  testFix = {
  expr = fix (x: {a = if x ? a then "a" else "b";});
  expected = {a = "a";};

diff --git a/lib/trivial.nix b/lib/trivial.nix
@@ -199,6 +199,24 @@ in {
  */
  and = x: y: x && y;
 
+ /**
+ boolean “exclusive or”
+
+
+ # Inputs
+
+ `x`
+
+ : 1\. Function argument
+
+ `y`
+
+ : 2\. Function argument
+ */
+ # We explicitly invert the arguments purely as a type assertion.
+ # This is invariant under XOR, so it does not affect the result.
+ xor = x: y: (!x) != (!y);
+
  /**
  bitwise “not”
  */

diff --git a/nixos/modules/config/users-groups.nix b/nixos/modules/config/users-groups.nix
@@ -871,7 +871,6 @@ in {
  }
  {
  assertion = let
- xor = a: b: a && !b || b && !a;
  isEffectivelySystemUser = user.isSystemUser || (user.uid != null && user.uid < 1000);
  in xor isEffectivelySystemUser user.isNormalUser;
  message = ''

diff --git a/nixos/modules/services/networking/kea.nix b/nixos/modules/services/networking/kea.nix
@@ -9,7 +9,6 @@ with lib;
 let
  cfg = config.services.kea;
 
- xor = x: y: (!x && y) || (x && !y);
  format = pkgs.formats.json {};
 
  chooseNotNull = x: y: if x != null then x else y;

diff --git a/pkgs/development/compilers/llvm/13/default.nix b/pkgs/development/compilers/llvm/13/default.nix
@@ -42,12 +42,9 @@
 
 }:
 
-assert let
- int = a: if a then 1 else 0;
- xor = a: b: ((builtins.bitXor (int a) (int b)) == 1);
-in
+assert
  lib.assertMsg
- (xor
+ (lib.xor
  (gitRelease != null)
  (officialRelease != null))
  ("must specify `gitRelease` or `officialRelease`" +

diff --git a/pkgs/development/compilers/llvm/14/default.nix b/pkgs/development/compilers/llvm/14/default.nix
@@ -41,12 +41,9 @@
 , monorepoSrc ? null
 }:
 
-assert let
- int = a: if a then 1 else 0;
- xor = a: b: ((builtins.bitXor (int a) (int b)) == 1);
-in
+assert
  lib.assertMsg
- (xor
+ (lib.xor
  (gitRelease != null)
  (officialRelease != null))
  ("must specify `gitRelease` or `officialRelease`" +

diff --git a/pkgs/development/compilers/llvm/15/default.nix b/pkgs/development/compilers/llvm/15/default.nix
@@ -41,12 +41,9 @@
 , monorepoSrc ? null
 }:
 
-assert let
- int = a: if a then 1 else 0;
- xor = a: b: ((builtins.bitXor (int a) (int b)) == 1);
-in
+assert
  lib.assertMsg
- (xor
+ (lib.xor
  (gitRelease != null)
  (officialRelease != null))
  ("must specify `gitRelease` or `officialRelease`" +

diff --git a/pkgs/development/compilers/llvm/16/default.nix b/pkgs/development/compilers/llvm/16/default.nix
@@ -41,12 +41,9 @@
 , monorepoSrc ? null
 }:
 
-assert let
- int = a: if a then 1 else 0;
- xor = a: b: ((builtins.bitXor (int a) (int b)) == 1);
-in
+assert
  lib.assertMsg
- (xor
+ (lib.xor
  (gitRelease != null)
  (officialRelease != null))
  ("must specify `gitRelease` or `officialRelease`" +

diff --git a/pkgs/development/compilers/llvm/17/default.nix b/pkgs/development/compilers/llvm/17/default.nix
@@ -41,12 +41,9 @@
 , monorepoSrc ? null
 }:
 
-assert let
- int = a: if a then 1 else 0;
- xor = a: b: ((builtins.bitXor (int a) (int b)) == 1);
-in
+assert
  lib.assertMsg
- (xor
+ (lib.xor
  (gitRelease != null)
  (officialRelease != null))
  ("must specify `gitRelease` or `officialRelease`" +

diff --git a/pkgs/development/compilers/llvm/18/default.nix b/pkgs/development/compilers/llvm/18/default.nix
@@ -41,12 +41,9 @@
 , monorepoSrc ? null
 }:
 
-assert let
- int = a: if a then 1 else 0;
- xor = a: b: ((builtins.bitXor (int a) (int b)) == 1);
-in
+assert
  lib.assertMsg
- (xor
+ (lib.xor
  (gitRelease != null)
  (officialRelease != null))
  ("must specify `gitRelease` or `officialRelease`" +

diff --git a/pkgs/development/compilers/llvm/git/default.nix b/pkgs/development/compilers/llvm/git/default.nix
@@ -46,12 +46,9 @@
 , monorepoSrc ? null
 }:
 
-assert let
- int = a: if a then 1 else 0;
- xor = a: b: ((builtins.bitXor (int a) (int b)) == 1);
-in
+assert
  lib.assertMsg
- (xor
+ (lib.xor
  (gitRelease != null)
  (officialRelease != null))
  ("must specify `gitRelease` or `officialRelease`" +