diff options
Diffstat (limited to '')
-rw-r--r-- | third_party/nix/src/libexpr/value.hh | 102 |
1 files changed, 59 insertions, 43 deletions
diff --git a/third_party/nix/src/libexpr/value.hh b/third_party/nix/src/libexpr/value.hh index 211b1669f8d4..1f41cf04bb30 100644 --- a/third_party/nix/src/libexpr/value.hh +++ b/third_party/nix/src/libexpr/value.hh @@ -89,59 +89,75 @@ class ExternalValueBase { std::ostream& operator<<(std::ostream& str, const ExternalValueBase& v); -struct Value { - ValueType type; - union { - NixInt integer; - bool boolean; +// Forward declaration of Value is required because the following +// types are mutually recursive. +// +// TODO(tazjin): Really, these types need some serious refactoring. +struct Value; + +/* Strings in the evaluator carry a so-called `context' which + is a list of strings representing store paths. This is to + allow users to write things like + + "--with-freetype2-library=" + freetype + "/lib" + + where `freetype' is a derivation (or a source to be copied + to the store). If we just concatenated the strings without + keeping track of the referenced store paths, then if the + string is used as a derivation attribute, the derivation + will not have the correct dependencies in its inputDrvs and + inputSrcs. + + The semantics of the context is as follows: when a string + with context C is used as a derivation attribute, then the + derivations in C will be added to the inputDrvs of the + derivation, and the other store paths in C will be added to + the inputSrcs of the derivations. + + For canonicity, the store paths should be in sorted order. */ +struct NixString { + const char* s; + const char** context; // must be in sorted order +}; - /* Strings in the evaluator carry a so-called `context' which - is a list of strings representing store paths. This is to - allow users to write things like +struct NixBigList { + size_t size; + Value** elems; +}; - "--with-freetype2-library=" + freetype + "/lib" +struct NixThunk { + Env* env; + Expr* expr; +}; - where `freetype' is a derivation (or a source to be copied - to the store). If we just concatenated the strings without - keeping track of the referenced store paths, then if the - string is used as a derivation attribute, the derivation - will not have the correct dependencies in its inputDrvs and - inputSrcs. +struct NixApp { + Value *left, *right; +}; - The semantics of the context is as follows: when a string - with context C is used as a derivation attribute, then the - derivations in C will be added to the inputDrvs of the - derivation, and the other store paths in C will be added to - the inputSrcs of the derivations. +struct NixLambda { + Env* env; + ExprLambda* fun; +}; - For canonicity, the store paths should be in sorted order. */ - struct { - const char* s; - const char** context; // must be in sorted order - } string; +struct NixPrimOpApp { + Value *left, *right; +}; +struct Value { + ValueType type; + union { // TODO(tazjin): std::variant + NixInt integer; + bool boolean; + NixString string; const char* path; Bindings* attrs; - struct { - size_t size; - Value** elems; - } bigList; + NixBigList bigList; Value* smallList[2]; - struct { - Env* env; - Expr* expr; - } thunk; - struct { - Value *left, *right; - } app; - struct { - Env* env; - ExprLambda* fun; - } lambda; + NixThunk thunk; + NixApp app; // TODO(tazjin): "app"? + NixLambda lambda; PrimOp* primOp; - struct { - Value *left, *right; - } primOpApp; + NixPrimOpApp primOpApp; ExternalValueBase* external; NixFloat fpoint; }; |