Function ExpandExistsMacro

parser/macro.cc:117–142

}

absl::optional<Expr> ExpandExistsMacro(MacroExprFactory& factory, Expr& target,
                                       absl::Span<Expr> args) {
  if (args.size() != 2) {
    return factory.ReportError("exists() requires 2 arguments");
  }
  if (!args[0].has_ident_expr() || args[0].ident_expr().name().empty()) {
    return factory.ReportErrorAt(
        args[0], "exists() variable name must be a simple identifier");
  }
  if (args[0].ident_expr().name() == kAccumulatorVariableName) {
    return factory.ReportErrorAt(
        args[1], absl::StrCat("exists() variable name cannot be ",
                              kAccumulatorVariableName));
  }
  auto init = factory.NewBoolConst(false);
  auto condition = factory.NewCall(
      CelOperator::NOT_STRICTLY_FALSE,
      factory.NewCall(CelOperator::LOGICAL_NOT, factory.NewAccuIdent()));
  auto step = factory.NewCall(CelOperator::LOGICAL_OR, factory.NewAccuIdent(),
                              std::move(args[1]));
  auto result = factory.NewAccuIdent();
  return factory.NewComprehension(args[0].ident_expr().name(),
                                  std::move(target), factory.AccuVarName(),
                                  std::move(init), std::move(condition),
                                  std::move(step), std::move(result));
}

Macro MakeExistsMacro() {
  auto status_or_macro =