about summary refs log tree commit diff
path: root/tvix/eval/src/tests/tvix_tests/notyetpassing/eval-okay-non-identifier-pointer-inequality.nix
diff options
context:
space:
mode:
Diffstat (limited to 'tvix/eval/src/tests/tvix_tests/notyetpassing/eval-okay-non-identifier-pointer-inequality.nix')
-rw-r--r--tvix/eval/src/tests/tvix_tests/notyetpassing/eval-okay-non-identifier-pointer-inequality.nix28
1 files changed, 28 insertions, 0 deletions
diff --git a/tvix/eval/src/tests/tvix_tests/notyetpassing/eval-okay-non-identifier-pointer-inequality.nix b/tvix/eval/src/tests/tvix_tests/notyetpassing/eval-okay-non-identifier-pointer-inequality.nix
new file mode 100644
index 000000000000..821aa47a0d2c
--- /dev/null
+++ b/tvix/eval/src/tests/tvix_tests/notyetpassing/eval-okay-non-identifier-pointer-inequality.nix
@@ -0,0 +1,28 @@
+# C++ Nix frequently creates copies of Value structs when evaluating
+# a variety of expressions. As a result, pointer equality doesn't
+# work for many (all?) expressions that go beyond simple identifier
+# access from the scope: Even if the inner representation of the
+# value still has the same memory location, C++ Nix has created
+# a copy of the struct that holds the pointer to this memory.
+# Since pointer equality is established via the location of
+# the latter, not the former, the values are no longer equal
+# by pointer.
+let
+  foo = { bar = x: x; };
+
+  id = x: x;
+in
+
+[
+  ({ inherit (foo) bar; } == { inherit (foo) bar; })
+  ([ foo.bar ] == [ foo.bar ])
+
+  ([ builtins.add ] == [ builtins.add ])
+  ({ inherit (builtins) import; } == { inherit (builtins) import; })
+
+  ([ (id id) ] == [ (id id) ])
+  ([ id ] == [ id ])
+
+  (with foo; [ bar ] == [ bar ])
+  (with builtins; [ add ] == [ add ])
+]