chore(3p/nix): unvendor tvix 0.1 r/4098

Nothing is using this now, and we'll likely never pick this up again,
but we learned a lot in the process.

Every now and then this breaks in some bizarre way on channel bumps
and it's just a waste of time to maintain that.

Change-Id: Idcf2f5acd4ca7070ce18d7149cbfc0d967dc0a44
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5632
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: lukegb <lukegb@tvl.fyi>
Autosubmit: tazjin <tazjin@tvl.su>

1 files changed, 0 insertions, 69 deletions

diff --git a/third_party/nix/src/libexpr/symbol-table.hh b/third_party/nix/src/libexpr/symbol-table.hh
deleted file mode 100644
index c2599658859f..000000000000
--- a/third_party/nix/src/libexpr/symbol-table.hh
+++ /dev/null
@@ -1,69 +0,0 @@
-#pragma once
-
-#include <absl/container/node_hash_set.h>
-#include <absl/strings/string_view.h>
-
-namespace nix {  // TODO(tazjin): ::expr
-
-// TODO(tazjin): Replace with a simpler struct, or get rid of.
-class Symbol {
- private:
-  const std::string* s;  // pointer into SymbolTable
-  Symbol(const std::string* s) : s(s){};
-  friend class SymbolTable;
-
- public:
-  bool operator==(const Symbol& s2) const { return s == s2.s; }
-
-  bool operator!=(const Symbol& s2) const { return s != s2.s; }
-
-  bool operator<(const Symbol& s2) const { return *s < *s2.s; }
-
-  operator const std::string&() const { return *s; }
-
-  bool set() const { return s; }
-
-  bool empty() const { return s->empty(); }
-
-  friend std::ostream& operator<<(std::ostream& str, const Symbol& sym);
-
-  template <typename H>
-  friend H AbslHashValue(H h, const Symbol& c) {
-    return H::combine(std::move(h), c.s);
-  }
-};
-
-// SymbolTable is a hash-set based symbol-interning mechanism.
-//
-// TODO(tazjin): Figure out which things use this. AttrSets, ...?
-// Is it possible this only exists because AttrSet wasn't a map?
-//
-// Original comment:
-//
-// Symbol table used by the parser and evaluator to represent and look
-// up identifiers and attributes efficiently. SymbolTable::create()
-// converts a string into a symbol. Symbols have the property that
-// they can be compared efficiently (using a pointer equality test),
-// because the symbol table stores only one copy of each string.
-class SymbolTable {
- public:
-  // Create a new symbol in this table by emplacing the provided
-  // string into it.
-  //
-  // The symbol will reference an existing symbol if the symbol is
-  // already interned.
-  Symbol Create(absl::string_view sym);
-
-  // Return the number of symbols interned.
-  size_t Size() const;
-
-  // Return the total size (in bytes)
-  size_t TotalSize() const;
-
- private:
-  // flat_hash_set does not retain pointer stability on rehashing,
-  // hence "interned" strings/symbols are stored on the heap.
-  absl::node_hash_set<std::string> symbols_;
-};
-
-}  // namespace nix