wgtmac commented on code in PR #553:
URL: https://github.com/apache/iceberg-cpp/pull/553#discussion_r2851594097


##########
src/iceberg/expression/json_serde_internal.h:
##########
@@ -19,6 +19,8 @@
 
 #pragma once
 
+#include <charconv>

Review Comment:
   Nit: `<charconv>` is included but never used in this header or in 
`json_serde.cc`. Please remove it.



##########
src/iceberg/expression/json_serde.cc:
##########
@@ -58,6 +69,53 @@ constexpr std::string_view kTypeCountNull = "count-null";
 constexpr std::string_view kTypeCountStar = "count-star";
 constexpr std::string_view kTypeMin = "min";
 constexpr std::string_view kTypeMax = "max";
+constexpr std::string_view kTypeLiteral = "literal";
+constexpr std::string_view kTypeReference = "reference";
+
+/// Helper to check if a JSON term represents a transform
+bool IsTransformTerm(const nlohmann::json& json) {
+  return json.is_object() && json.contains(kType) &&
+         json[kType].get<std::string>() == kTransform && json.contains(kTerm);
+}
+
+/// Template helper to create predicates from JSON with the appropriate term 
type
+template <typename B>
+Result<std::unique_ptr<UnboundPredicate>> MakePredicateFromJson(
+    Expression::Operation op, std::shared_ptr<UnboundTerm<B>> term,
+    const nlohmann::json& json) {
+  if (IsUnaryOperation(op)) {
+    if (json.contains(kValue)) [[unlikely]] {
+      return JsonParseError("Unary predicate has invalid 'value' field: {}",
+                            SafeDumpJson(json));
+    }
+    if (json.contains(kValues)) [[unlikely]] {
+      return JsonParseError("Unary predicate has invalid 'values' field: {}",
+                            SafeDumpJson(json));
+    }
+    return UnboundPredicateImpl<B>::Make(op, std::move(term));
+  }
+
+  if (IsSetOperation(op)) {
+    std::vector<Literal> literals;
+    if (!json.contains(kValues) || !json[kValues].is_array()) [[unlikely]] {

Review Comment:
   Java's `predicateFromJson` validates that set predicates (IN/NOT_IN) do not 
have a `value` field. This cross-validation is missing here. A malformed JSON 
with both `value` and `values` would be silently accepted.



##########
src/iceberg/expression/json_serde.cc:
##########
@@ -123,27 +181,252 @@ nlohmann::json ToJson(Expression::Operation op) {
   return json;
 }
 
+nlohmann::json ToJson(const NamedReference& ref) { return ref.name(); }
+
+Result<std::unique_ptr<NamedReference>> NamedReferenceFromJson(
+    const nlohmann::json& json) {
+  if (json.is_object() && json.contains(kType) &&
+      json[kType].get<std::string>() == kTypeReference && 
json.contains(kTerm)) {
+    return NamedReference::Make(json[kTerm].get<std::string>());
+  }
+  if (!json.is_string()) [[unlikely]] {
+    return JsonParseError("Expected string for named reference");
+  }
+  return NamedReference::Make(json.get<std::string>());
+}
+
+nlohmann::json ToJson(const UnboundTransform& transform) {
+  auto& mutable_transform = const_cast<UnboundTransform&>(transform);
+  nlohmann::json json;
+  json[kType] = kTransform;
+  json[kTransform] = transform.transform()->ToString();
+  json[kTerm] = mutable_transform.reference()->name();
+  return json;
+}
+
+Result<std::unique_ptr<UnboundTransform>> UnboundTransformFromJson(
+    const nlohmann::json& json) {
+  if (IsTransformTerm(json)) {
+    ICEBERG_ASSIGN_OR_RAISE(auto transform_str,
+                            GetJsonValue<std::string>(json, kTransform));
+    ICEBERG_ASSIGN_OR_RAISE(auto transform, 
TransformFromString(transform_str));
+    ICEBERG_ASSIGN_OR_RAISE(auto ref, NamedReferenceFromJson(json[kTerm]));
+    return UnboundTransform::Make(std::move(ref), std::move(transform));
+  }
+  return JsonParseError("Invalid unbound transform json: {}", 
SafeDumpJson(json));
+}
+
+nlohmann::json ToJson(const Literal& literal) {
+  if (literal.IsNull()) {
+    return nullptr;
+  }
+
+  const auto type_id = literal.type()->type_id();
+  const auto& value = literal.value();
+
+  switch (type_id) {
+    case TypeId::kBoolean:
+      return std::get<bool>(value);
+    case TypeId::kInt:
+      return std::get<int32_t>(value);
+    case TypeId::kDate:
+      return TransformUtil::HumanDay(std::get<int32_t>(value));
+    case TypeId::kLong:
+      return std::get<int64_t>(value);
+    case TypeId::kTime:
+      return TransformUtil::HumanTime(std::get<int64_t>(value));
+    case TypeId::kTimestamp:
+      return TransformUtil::HumanTimestamp(std::get<int64_t>(value));
+    case TypeId::kTimestampTz:
+      return TransformUtil::HumanTimestampWithZone(std::get<int64_t>(value));
+    case TypeId::kFloat:
+      return std::get<float>(value);
+    case TypeId::kDouble:
+      return std::get<double>(value);
+    case TypeId::kString:
+      return std::get<std::string>(value);
+    case TypeId::kBinary:
+    case TypeId::kFixed: {
+      const auto& bytes = std::get<std::vector<uint8_t>>(value);
+      std::string hex;
+      hex.reserve(bytes.size() * 2);
+      for (uint8_t byte : bytes) {
+        hex += std::format("{:02X}", byte);
+      }
+      return hex;
+    }
+    case TypeId::kDecimal: {
+      return literal.ToString();
+    }
+    case TypeId::kUuid:
+      return std::get<Uuid>(value).ToString();
+    default:
+      nlohmann::json json;
+      return json;
+  }
+}
+
+Result<Literal> LiteralFromJson(const nlohmann::json& json) {
+  // Unwrap {"type": "literal", "value": <actual>} wrapper
+  if (json.is_object() && json.contains(kType) &&
+      json[kType].get<std::string>() == kTypeLiteral && json.contains(kValue)) 
{
+    return LiteralFromJson(json[kValue]);
+  }
+  if (json.is_null()) {
+    return Literal::Null(nullptr);
+  }
+  if (json.is_boolean()) {
+    return Literal::Boolean(json.get<bool>());
+  }
+  if (json.is_number_integer()) {
+    return Literal::Long(json.get<int64_t>());
+  }
+  if (json.is_number_float()) {
+    return Literal::Double(json.get<double>());
+  }
+  if (json.is_string()) {
+    // All strings are returned as String literals.
+    // Conversion to binary/date/time/etc. happens during binding
+    // when schema type information is available.
+    return Literal::String(json.get<std::string>());
+  }
+  return JsonParseError("Unsupported literal JSON type");
+}
+
+nlohmann::json TermToJson(const Term& term) {
+  switch (term.kind()) {
+    case Term::Kind::kReference:
+      return ToJson(static_cast<const NamedReference&>(term));
+    case Term::Kind::kTransform:
+      return ToJson(static_cast<const UnboundTransform&>(term));
+    default:
+      return nullptr;
+  }
+}
+
+nlohmann::json ToJson(const UnboundPredicate& pred) {
+  nlohmann::json json;
+  json[kType] = ToJson(pred.op());
+
+  // Get term and literals by casting to the appropriate impl type
+  std::span<const Literal> literals;
+
+  if (auto* ref_pred = dynamic_cast<const 
UnboundPredicateImpl<BoundReference>*>(&pred)) {
+    json[kTerm] = TermToJson(*ref_pred->term());
+    literals = ref_pred->literals();
+  } else if (auto* transform_pred =
+                 dynamic_cast<const 
UnboundPredicateImpl<BoundTransform>*>(&pred)) {
+    json[kTerm] = TermToJson(*transform_pred->term());
+    literals = transform_pred->literals();
+  }
+
+  if (!IsUnaryOperation(pred.op())) {
+    if (IsSetOperation(pred.op())) {
+      nlohmann::json values = nlohmann::json::array();
+      for (const auto& lit : literals) {
+        values.push_back(ToJson(lit));
+      }
+      json[kValues] = std::move(values);
+    } else if (!literals.empty()) {
+      json[kValue] = ToJson(literals[0]);
+    }
+  }
+  return json;
+}
+
+Result<std::unique_ptr<UnboundPredicate>> UnboundPredicateFromJson(
+    const nlohmann::json& json) {
+  ICEBERG_ASSIGN_OR_RAISE(auto op, OperationTypeFromJson(json[kType]));

Review Comment:
   No check for `json.contains(kType)` before accessing `json[kType]`. If the 
`type` field is missing, this will either throw or silently insert a null.



##########
src/iceberg/expression/json_serde.cc:
##########
@@ -123,27 +181,252 @@ nlohmann::json ToJson(Expression::Operation op) {
   return json;
 }
 
+nlohmann::json ToJson(const NamedReference& ref) { return ref.name(); }
+
+Result<std::unique_ptr<NamedReference>> NamedReferenceFromJson(
+    const nlohmann::json& json) {
+  if (json.is_object() && json.contains(kType) &&
+      json[kType].get<std::string>() == kTypeReference && 
json.contains(kTerm)) {
+    return NamedReference::Make(json[kTerm].get<std::string>());
+  }
+  if (!json.is_string()) [[unlikely]] {
+    return JsonParseError("Expected string for named reference");
+  }
+  return NamedReference::Make(json.get<std::string>());
+}
+
+nlohmann::json ToJson(const UnboundTransform& transform) {
+  auto& mutable_transform = const_cast<UnboundTransform&>(transform);
+  nlohmann::json json;
+  json[kType] = kTransform;
+  json[kTransform] = transform.transform()->ToString();
+  json[kTerm] = mutable_transform.reference()->name();
+  return json;
+}
+
+Result<std::unique_ptr<UnboundTransform>> UnboundTransformFromJson(
+    const nlohmann::json& json) {
+  if (IsTransformTerm(json)) {
+    ICEBERG_ASSIGN_OR_RAISE(auto transform_str,
+                            GetJsonValue<std::string>(json, kTransform));
+    ICEBERG_ASSIGN_OR_RAISE(auto transform, 
TransformFromString(transform_str));
+    ICEBERG_ASSIGN_OR_RAISE(auto ref, NamedReferenceFromJson(json[kTerm]));
+    return UnboundTransform::Make(std::move(ref), std::move(transform));
+  }
+  return JsonParseError("Invalid unbound transform json: {}", 
SafeDumpJson(json));
+}
+
+nlohmann::json ToJson(const Literal& literal) {
+  if (literal.IsNull()) {
+    return nullptr;
+  }
+
+  const auto type_id = literal.type()->type_id();
+  const auto& value = literal.value();
+
+  switch (type_id) {
+    case TypeId::kBoolean:
+      return std::get<bool>(value);
+    case TypeId::kInt:
+      return std::get<int32_t>(value);
+    case TypeId::kDate:
+      return TransformUtil::HumanDay(std::get<int32_t>(value));
+    case TypeId::kLong:
+      return std::get<int64_t>(value);
+    case TypeId::kTime:
+      return TransformUtil::HumanTime(std::get<int64_t>(value));
+    case TypeId::kTimestamp:
+      return TransformUtil::HumanTimestamp(std::get<int64_t>(value));
+    case TypeId::kTimestampTz:
+      return TransformUtil::HumanTimestampWithZone(std::get<int64_t>(value));
+    case TypeId::kFloat:
+      return std::get<float>(value);
+    case TypeId::kDouble:
+      return std::get<double>(value);
+    case TypeId::kString:
+      return std::get<std::string>(value);
+    case TypeId::kBinary:
+    case TypeId::kFixed: {
+      const auto& bytes = std::get<std::vector<uint8_t>>(value);
+      std::string hex;
+      hex.reserve(bytes.size() * 2);
+      for (uint8_t byte : bytes) {
+        hex += std::format("{:02X}", byte);
+      }
+      return hex;
+    }
+    case TypeId::kDecimal: {
+      return literal.ToString();
+    }
+    case TypeId::kUuid:
+      return std::get<Uuid>(value).ToString();
+    default:
+      nlohmann::json json;
+      return json;
+  }
+}
+
+Result<Literal> LiteralFromJson(const nlohmann::json& json) {
+  // Unwrap {"type": "literal", "value": <actual>} wrapper
+  if (json.is_object() && json.contains(kType) &&
+      json[kType].get<std::string>() == kTypeLiteral && json.contains(kValue)) 
{
+    return LiteralFromJson(json[kValue]);
+  }
+  if (json.is_null()) {
+    return Literal::Null(nullptr);
+  }
+  if (json.is_boolean()) {
+    return Literal::Boolean(json.get<bool>());
+  }
+  if (json.is_number_integer()) {
+    return Literal::Long(json.get<int64_t>());
+  }
+  if (json.is_number_float()) {
+    return Literal::Double(json.get<double>());
+  }
+  if (json.is_string()) {
+    // All strings are returned as String literals.
+    // Conversion to binary/date/time/etc. happens during binding
+    // when schema type information is available.
+    return Literal::String(json.get<std::string>());
+  }
+  return JsonParseError("Unsupported literal JSON type");
+}
+
+nlohmann::json TermToJson(const Term& term) {
+  switch (term.kind()) {
+    case Term::Kind::kReference:
+      return ToJson(static_cast<const NamedReference&>(term));
+    case Term::Kind::kTransform:
+      return ToJson(static_cast<const UnboundTransform&>(term));
+    default:
+      return nullptr;
+  }
+}
+
+nlohmann::json ToJson(const UnboundPredicate& pred) {
+  nlohmann::json json;
+  json[kType] = ToJson(pred.op());
+
+  // Get term and literals by casting to the appropriate impl type
+  std::span<const Literal> literals;
+
+  if (auto* ref_pred = dynamic_cast<const 
UnboundPredicateImpl<BoundReference>*>(&pred)) {
+    json[kTerm] = TermToJson(*ref_pred->term());
+    literals = ref_pred->literals();
+  } else if (auto* transform_pred =
+                 dynamic_cast<const 
UnboundPredicateImpl<BoundTransform>*>(&pred)) {
+    json[kTerm] = TermToJson(*transform_pred->term());
+    literals = transform_pred->literals();
+  }
+
+  if (!IsUnaryOperation(pred.op())) {
+    if (IsSetOperation(pred.op())) {
+      nlohmann::json values = nlohmann::json::array();
+      for (const auto& lit : literals) {
+        values.push_back(ToJson(lit));
+      }
+      json[kValues] = std::move(values);
+    } else if (!literals.empty()) {
+      json[kValue] = ToJson(literals[0]);
+    }
+  }
+  return json;
+}
+
+Result<std::unique_ptr<UnboundPredicate>> UnboundPredicateFromJson(
+    const nlohmann::json& json) {
+  ICEBERG_ASSIGN_OR_RAISE(auto op, OperationTypeFromJson(json[kType]));
+
+  const auto& term_json = json[kTerm];
+
+  if (IsTransformTerm(term_json)) {
+    ICEBERG_ASSIGN_OR_RAISE(auto term, UnboundTransformFromJson(term_json));
+    return MakePredicateFromJson<BoundTransform>(op, std::move(term), json);
+  }
+
+  ICEBERG_ASSIGN_OR_RAISE(auto term, NamedReferenceFromJson(term_json));
+  return MakePredicateFromJson<BoundReference>(op, std::move(term), json);
+}
+
 Result<std::shared_ptr<Expression>> ExpressionFromJson(const nlohmann::json& 
json) {
-  // Handle boolean
+  // Handle boolean constants
   if (json.is_boolean()) {
     return json.get<bool>()
                ? internal::checked_pointer_cast<Expression>(True::Instance())
                : internal::checked_pointer_cast<Expression>(False::Instance());
   }
-  return JsonParseError("Only booleans are currently supported.");
+
+  if (!json.is_object()) [[unlikely]] {
+    return JsonParseError("Expression must be boolean or object");
+  }
+
+  ICEBERG_ASSIGN_OR_RAISE(auto op, OperationTypeFromJson(json[kType]));

Review Comment:
   Check `kType` as well?



##########
src/iceberg/expression/json_serde.cc:
##########
@@ -58,6 +69,53 @@ constexpr std::string_view kTypeCountNull = "count-null";
 constexpr std::string_view kTypeCountStar = "count-star";
 constexpr std::string_view kTypeMin = "min";
 constexpr std::string_view kTypeMax = "max";
+constexpr std::string_view kTypeLiteral = "literal";
+constexpr std::string_view kTypeReference = "reference";
+
+/// Helper to check if a JSON term represents a transform
+bool IsTransformTerm(const nlohmann::json& json) {
+  return json.is_object() && json.contains(kType) &&
+         json[kType].get<std::string>() == kTransform && json.contains(kTerm);
+}
+
+/// Template helper to create predicates from JSON with the appropriate term 
type
+template <typename B>
+Result<std::unique_ptr<UnboundPredicate>> MakePredicateFromJson(
+    Expression::Operation op, std::shared_ptr<UnboundTerm<B>> term,
+    const nlohmann::json& json) {
+  if (IsUnaryOperation(op)) {
+    if (json.contains(kValue)) [[unlikely]] {
+      return JsonParseError("Unary predicate has invalid 'value' field: {}",
+                            SafeDumpJson(json));
+    }
+    if (json.contains(kValues)) [[unlikely]] {
+      return JsonParseError("Unary predicate has invalid 'values' field: {}",
+                            SafeDumpJson(json));
+    }
+    return UnboundPredicateImpl<B>::Make(op, std::move(term));
+  }
+
+  if (IsSetOperation(op)) {
+    std::vector<Literal> literals;
+    if (!json.contains(kValues) || !json[kValues].is_array()) [[unlikely]] {
+      return JsonParseError("Missing or invalid 'values' field for set 
operation: {}",
+                            SafeDumpJson(json));
+    }
+    for (const auto& val : json[kValues]) {
+      ICEBERG_ASSIGN_OR_RAISE(auto lit, LiteralFromJson(val));
+      literals.push_back(std::move(lit));
+    }
+    return UnboundPredicateImpl<B>::Make(op, std::move(term), 
std::move(literals));
+  }
+
+  // Literal predicate
+  if (!json.contains(kValue)) [[unlikely]] {

Review Comment:
   Similarly, Java validates that literal predicates (LT, EQ, etc.) do not have 
a `values` field.



##########
src/iceberg/expression/json_serde.cc:
##########
@@ -123,27 +181,252 @@ nlohmann::json ToJson(Expression::Operation op) {
   return json;
 }
 
+nlohmann::json ToJson(const NamedReference& ref) { return ref.name(); }
+
+Result<std::unique_ptr<NamedReference>> NamedReferenceFromJson(
+    const nlohmann::json& json) {
+  if (json.is_object() && json.contains(kType) &&
+      json[kType].get<std::string>() == kTypeReference && 
json.contains(kTerm)) {
+    return NamedReference::Make(json[kTerm].get<std::string>());
+  }
+  if (!json.is_string()) [[unlikely]] {
+    return JsonParseError("Expected string for named reference");
+  }
+  return NamedReference::Make(json.get<std::string>());
+}
+
+nlohmann::json ToJson(const UnboundTransform& transform) {
+  auto& mutable_transform = const_cast<UnboundTransform&>(transform);
+  nlohmann::json json;
+  json[kType] = kTransform;
+  json[kTransform] = transform.transform()->ToString();
+  json[kTerm] = mutable_transform.reference()->name();
+  return json;
+}
+
+Result<std::unique_ptr<UnboundTransform>> UnboundTransformFromJson(
+    const nlohmann::json& json) {
+  if (IsTransformTerm(json)) {
+    ICEBERG_ASSIGN_OR_RAISE(auto transform_str,
+                            GetJsonValue<std::string>(json, kTransform));
+    ICEBERG_ASSIGN_OR_RAISE(auto transform, 
TransformFromString(transform_str));
+    ICEBERG_ASSIGN_OR_RAISE(auto ref, NamedReferenceFromJson(json[kTerm]));
+    return UnboundTransform::Make(std::move(ref), std::move(transform));
+  }
+  return JsonParseError("Invalid unbound transform json: {}", 
SafeDumpJson(json));
+}
+
+nlohmann::json ToJson(const Literal& literal) {
+  if (literal.IsNull()) {
+    return nullptr;
+  }
+
+  const auto type_id = literal.type()->type_id();
+  const auto& value = literal.value();
+
+  switch (type_id) {
+    case TypeId::kBoolean:
+      return std::get<bool>(value);
+    case TypeId::kInt:
+      return std::get<int32_t>(value);
+    case TypeId::kDate:
+      return TransformUtil::HumanDay(std::get<int32_t>(value));
+    case TypeId::kLong:
+      return std::get<int64_t>(value);
+    case TypeId::kTime:
+      return TransformUtil::HumanTime(std::get<int64_t>(value));
+    case TypeId::kTimestamp:
+      return TransformUtil::HumanTimestamp(std::get<int64_t>(value));
+    case TypeId::kTimestampTz:
+      return TransformUtil::HumanTimestampWithZone(std::get<int64_t>(value));
+    case TypeId::kFloat:
+      return std::get<float>(value);
+    case TypeId::kDouble:
+      return std::get<double>(value);
+    case TypeId::kString:
+      return std::get<std::string>(value);
+    case TypeId::kBinary:
+    case TypeId::kFixed: {
+      const auto& bytes = std::get<std::vector<uint8_t>>(value);
+      std::string hex;
+      hex.reserve(bytes.size() * 2);
+      for (uint8_t byte : bytes) {
+        hex += std::format("{:02X}", byte);
+      }
+      return hex;
+    }
+    case TypeId::kDecimal: {
+      return literal.ToString();
+    }
+    case TypeId::kUuid:
+      return std::get<Uuid>(value).ToString();
+    default:
+      nlohmann::json json;
+      return json;
+  }
+}
+
+Result<Literal> LiteralFromJson(const nlohmann::json& json) {
+  // Unwrap {"type": "literal", "value": <actual>} wrapper
+  if (json.is_object() && json.contains(kType) &&
+      json[kType].get<std::string>() == kTypeLiteral && json.contains(kValue)) 
{
+    return LiteralFromJson(json[kValue]);
+  }
+  if (json.is_null()) {
+    return Literal::Null(nullptr);
+  }
+  if (json.is_boolean()) {
+    return Literal::Boolean(json.get<bool>());
+  }
+  if (json.is_number_integer()) {
+    return Literal::Long(json.get<int64_t>());
+  }
+  if (json.is_number_float()) {
+    return Literal::Double(json.get<double>());
+  }
+  if (json.is_string()) {
+    // All strings are returned as String literals.
+    // Conversion to binary/date/time/etc. happens during binding
+    // when schema type information is available.
+    return Literal::String(json.get<std::string>());
+  }
+  return JsonParseError("Unsupported literal JSON type");
+}
+
+nlohmann::json TermToJson(const Term& term) {
+  switch (term.kind()) {
+    case Term::Kind::kReference:
+      return ToJson(static_cast<const NamedReference&>(term));
+    case Term::Kind::kTransform:
+      return ToJson(static_cast<const UnboundTransform&>(term));
+    default:
+      return nullptr;
+  }
+}
+
+nlohmann::json ToJson(const UnboundPredicate& pred) {
+  nlohmann::json json;
+  json[kType] = ToJson(pred.op());
+
+  // Get term and literals by casting to the appropriate impl type
+  std::span<const Literal> literals;
+
+  if (auto* ref_pred = dynamic_cast<const 
UnboundPredicateImpl<BoundReference>*>(&pred)) {
+    json[kTerm] = TermToJson(*ref_pred->term());
+    literals = ref_pred->literals();
+  } else if (auto* transform_pred =
+                 dynamic_cast<const 
UnboundPredicateImpl<BoundTransform>*>(&pred)) {
+    json[kTerm] = TermToJson(*transform_pred->term());
+    literals = transform_pred->literals();
+  }
+
+  if (!IsUnaryOperation(pred.op())) {
+    if (IsSetOperation(pred.op())) {
+      nlohmann::json values = nlohmann::json::array();
+      for (const auto& lit : literals) {
+        values.push_back(ToJson(lit));
+      }
+      json[kValues] = std::move(values);
+    } else if (!literals.empty()) {
+      json[kValue] = ToJson(literals[0]);
+    }
+  }
+  return json;
+}
+
+Result<std::unique_ptr<UnboundPredicate>> UnboundPredicateFromJson(
+    const nlohmann::json& json) {
+  ICEBERG_ASSIGN_OR_RAISE(auto op, OperationTypeFromJson(json[kType]));
+
+  const auto& term_json = json[kTerm];
+
+  if (IsTransformTerm(term_json)) {
+    ICEBERG_ASSIGN_OR_RAISE(auto term, UnboundTransformFromJson(term_json));
+    return MakePredicateFromJson<BoundTransform>(op, std::move(term), json);
+  }
+
+  ICEBERG_ASSIGN_OR_RAISE(auto term, NamedReferenceFromJson(term_json));
+  return MakePredicateFromJson<BoundReference>(op, std::move(term), json);
+}
+
 Result<std::shared_ptr<Expression>> ExpressionFromJson(const nlohmann::json& 
json) {
-  // Handle boolean
+  // Handle boolean constants
   if (json.is_boolean()) {
     return json.get<bool>()
                ? internal::checked_pointer_cast<Expression>(True::Instance())
                : internal::checked_pointer_cast<Expression>(False::Instance());
   }
-  return JsonParseError("Only booleans are currently supported.");
+
+  if (!json.is_object()) [[unlikely]] {
+    return JsonParseError("Expression must be boolean or object");
+  }
+
+  ICEBERG_ASSIGN_OR_RAISE(auto op, OperationTypeFromJson(json[kType]));
+
+  switch (op) {
+    case Expression::Operation::kAnd: {

Review Comment:
   Should we add kTrue and kFalse branches here?



-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]


---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to