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evaluate inherit (from) exprs only once per directive

desugaring inherit-from to syntactic duplication of the source expr also
duplicates side effects of the source expr (such as trace calls) and
expensive computations (such as derivationStrict).
This commit is contained in:
pennae 2024-01-27 16:33:34 +01:00
parent ecf8b12d60
commit cefd0302b5
9 changed files with 109 additions and 15 deletions

View file

@ -135,6 +135,18 @@ struct ExprVar : Expr
COMMON_METHODS
};
struct ExprInheritFrom : ExprVar
{
ExprInheritFrom(PosIdx pos, Displacement displ): ExprVar(pos, {})
{
this->level = 0;
this->displ = displ;
this->fromWith = nullptr;
}
void bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env);
};
struct ExprSelect : Expr
{
PosIdx pos;
@ -195,6 +207,7 @@ struct ExprAttrs : Expr
};
typedef std::map<Symbol, AttrDef> AttrDefs;
AttrDefs attrs;
std::unique_ptr<std::vector<Expr *>> inheritFromExprs;
struct DynamicAttrDef {
Expr * nameExpr, * valueExpr;
PosIdx pos;
@ -208,6 +221,9 @@ struct ExprAttrs : Expr
PosIdx getPos() const override { return pos; }
COMMON_METHODS
std::shared_ptr<const StaticEnv> bindInheritSources(
EvalState & es, const std::shared_ptr<const StaticEnv> & env);
Env * buildInheritFromEnv(EvalState & state, Env & up);
void showBindings(const SymbolTable & symbols, std::ostream & str) const;
};