lib.trivial: Remove unneeded polyfills

Nix 2.3 (the minimum version needed to evaluate Nixpkgs) supports these, so no need to keep them around.

2 files changed, 2 insertions, 56 deletions

diff --git a/lib/trivial.nix b/lib/trivial.nix
index 58620006de15..fa499cbbf028 100644
--- a/lib/trivial.nix
+++ b/lib/trivial.nix
@@ -95,21 +95,6 @@ in {
   /* boolean “and” */
   and = x: y: x && y;
 
-  /* bitwise “and” */
-  bitAnd = builtins.bitAnd
-    or (import ./zip-int-bits.nix
-        (a: b: if a==1 && b==1 then 1 else 0));
-
-  /* bitwise “or” */
-  bitOr = builtins.bitOr
-    or (import ./zip-int-bits.nix
-        (a: b: if a==1 || b==1 then 1 else 0));
-
-  /* bitwise “xor” */
-  bitXor = builtins.bitXor
-    or (import ./zip-int-bits.nix
-        (a: b: if a!=b then 1 else 0));
-
   /* bitwise “not” */
   bitNot = builtins.sub (-1);
 
@@ -165,8 +150,8 @@ in {
   inherit (builtins)
     pathExists readFile isBool
     isInt isFloat add sub lessThan
-    seq deepSeq genericClosure;
-
+    seq deepSeq genericClosure
+    bitAnd bitOr bitXor;
 
   ## nixpkgs version strings
 
diff --git a/lib/zip-int-bits.nix b/lib/zip-int-bits.nix
deleted file mode 100644
index 53efd2bb0a04..000000000000
--- a/lib/zip-int-bits.nix
+++ /dev/null
@@ -1,39 +0,0 @@
-/* Helper function to implement a fallback for the bit operators
-   `bitAnd`, `bitOr` and `bitXor` on older nix version.
-   See ./trivial.nix
-*/
-f: x: y:
-  let
-    # (intToBits 6) -> [ 0 1 1 ]
-    intToBits = x:
-      if x == 0 || x == -1 then
-        []
-      else
-        let
-          headbit  = if (x / 2) * 2 != x then 1 else 0;          # x & 1
-          tailbits = if x < 0 then ((x + 1) / 2) - 1 else x / 2; # x >> 1
-        in
-          [headbit] ++ (intToBits tailbits);
-
-    # (bitsToInt [ 0 1 1 ] 0) -> 6
-    # (bitsToInt [ 0 1 0 ] 1) -> -6
-    bitsToInt = l: signum:
-      if l == [] then
-        (if signum == 0 then 0 else -1)
-      else
-        (builtins.head l) + (2 * (bitsToInt (builtins.tail l) signum));
-
-    xsignum = if x < 0 then 1 else 0;
-    ysignum = if y < 0 then 1 else 0;
-    zipListsWith' = fst: snd:
-      if fst==[] && snd==[] then
-        []
-      else if fst==[] then
-        [(f xsignum             (builtins.head snd))] ++ (zipListsWith' []                  (builtins.tail snd))
-      else if snd==[] then
-        [(f (builtins.head fst) ysignum            )] ++ (zipListsWith' (builtins.tail fst) []                 )
-      else
-        [(f (builtins.head fst) (builtins.head snd))] ++ (zipListsWith' (builtins.tail fst) (builtins.tail snd));
-  in
-    assert (builtins.isInt x) && (builtins.isInt y);
-    bitsToInt (zipListsWith' (intToBits x) (intToBits y)) (f xsignum ysignum)