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diff --git a/tvix/eval/docs/language-issues.md b/tvix/eval/docs/language-issues.md deleted file mode 100644 index 152e6594a1d0..000000000000 --- a/tvix/eval/docs/language-issues.md +++ /dev/null @@ -1,46 +0,0 @@ -# Nix language issues - -In the absence of a language standard, what Nix (the language) is, is prescribed -by the behavior of the C++ Nix implementation. Still, there are reasons not to -accept some behavior: - -* Tvix aims for nixpkgs compatibility only. This means we can ignore behavior in - edge cases nixpkgs doesn't trigger as well as obscure features it doesn't use - (e.g. `__overrides`). -* Some behavior of the Nix evaluator seems to be unintentional or an - implementation detail leaking out into language behavior. - -Especially in the latter case, it makes sense to raise the respective issue and -maybe to get rid of the behavior in all implementations for good. Below is an -(incomplete) list of such issues: - -* [Behaviour of nested attribute sets depends on definition order][i7111] -* [Partially constructed attribute sets are observable during dynamic attr names construction][i7012] -* [Nix parsers merges multiple attribute set literals for the same key incorrectly depending on definition order][i7115] - -On the other hand, there is behavior that seems to violate one's expectation -about the language at first, but has good enough reasons from an implementor's -perspective to keep them: - -* Dynamic keys are forbidden in `let` and `inherit`. This makes sure that we - only need to do runtime identifier lookups for `with`. More dynamic (i.e. - runtime) lookups would make the scoping system even more complicated as well - as hurt performance. -* Dynamic attributes of `rec` sets are not added to its scope. This makes sense - for the same reason. -* Dynamic and nested attributes in attribute sets don't get merged. This is a - tricky one, but avoids doing runtime (recursive) merges of attribute sets. - Instead all necessary merging can be inferred statically, i.e. the C++ Nix - implementation already merges at parse time, making nested attribute keys - syntactic sugar effectively. - -Other behavior is just odd, surprising or underdocumented: - -* `builtins.foldl'` doesn't force the initial accumulator (but all other - intermediate accumulator values), differing from e.g. Haskell, see - the [relevant PR discussion][p7158]. - -[i7111]: https://github.com/NixOS/nix/issues/7111 -[i7012]: https://github.com/NixOS/nix/issues/7012 -[i7115]: https://github.com/NixOS/nix/issues/7115 -[p7158]: https://github.com/NixOS/nix/pull/7158 |