Function ExpandExistsOneMacro2

extensions/comprehensions_v2_macros.cc:135–179

}

absl::optional<Expr> ExpandExistsOneMacro2(MacroExprFactory& factory,
                                           Expr& target,
                                           absl::Span<Expr> args) {
  if (args.size() != 3) {
    return factory.ReportError("existsOne() requires 3 arguments");
  }
  if (!args[0].has_ident_expr() || args[0].ident_expr().name().empty()) {
    return factory.ReportErrorAt(
        args[0], "existsOne() first variable name must be a simple identifier");
  }
  if (!args[1].has_ident_expr() || args[1].ident_expr().name().empty()) {
    return factory.ReportErrorAt(
        args[1],
        "existsOne() second variable name must be a simple identifier");
  }
  if (args[0].ident_expr().name() == args[1].ident_expr().name()) {
    return factory.ReportErrorAt(
        args[0],
        "existsOne() second variable must be different "
        "from the first variable");
  }
  if (args[0].ident_expr().name() == kAccumulatorVariableName) {
    return factory.ReportErrorAt(
        args[0], absl::StrCat("existsOne() first variable name cannot be ",
                              kAccumulatorVariableName));
  }
  if (args[1].ident_expr().name() == kAccumulatorVariableName) {
    return factory.ReportErrorAt(
        args[1], absl::StrCat("existsOne() second variable name cannot be ",
                              kAccumulatorVariableName));
  }
  auto init = factory.NewIntConst(0);
  auto condition = factory.NewBoolConst(true);
  auto step =
      factory.NewCall(CelOperator::CONDITIONAL, std::move(args[2]),
                      factory.NewCall(CelOperator::ADD, factory.NewAccuIdent(),
                                      factory.NewIntConst(1)),
                      factory.NewAccuIdent());
  auto result = factory.NewCall(CelOperator::EQUALS, factory.NewAccuIdent(),
                                factory.NewIntConst(1));
  return factory.NewComprehension(
      args[0].ident_expr().name(), args[1].ident_expr().name(),
      std::move(target), factory.AccuVarName(), std::move(init),
      std::move(condition), std::move(step), std::move(result));
}

Macro MakeExistsOneMacro2() {
  auto status_or_macro = Macro::Receiver("existsOne", 3, ExpandExistsOneMacro2);