set or unary operation helper

Author: Innocent

src/iceberg/expression/json_serde.cc

@@ -54,6 +54,30 @@ constexpr std::string_view kTypeIsNan = "is-nan";
 constexpr std::string_view kTypeNotNan = "not-nan";
 }  // namespace
 
+/// Check if an operation is a unary predicate (no values)
+bool IsUnaryOperation(Expression::Operation op) {
+  switch (op) {
+    case Expression::Operation::kIsNull:
+    case Expression::Operation::kNotNull:
+    case Expression::Operation::kIsNan:
+    case Expression::Operation::kNotNan:
+      return true;
+    default:
+      return false;
+  }
+}
+
+/// Check if an operation is a set predicate (multiple values)
+bool IsSetOperation(Expression::Operation op) {
+  switch (op) {
+    case Expression::Operation::kIn:
+    case Expression::Operation::kNotIn:
+      return true;
+    default:
+      return false;
+  }
+}
+
 /// \brief Converts a JSON type string to an Expression::Operation.
 ///
 /// \param type_str The JSON type string

src/iceberg/expression/json_serde_internal.h

@@ -61,4 +61,10 @@ ICEBERG_EXPORT Result<Expression::Operation> OperationTypeFromString(
 /// \return The operation type string (e.g., "eq", "lt-eq", "is-null")
 ICEBERG_EXPORT std::string_view ToStringOperationType(Expression::Operation op);
 
+/// Check if an operation is a unary predicate (no values)
+ICEBERG_EXPORT bool IsUnaryOperation(Expression::Operation op);
+
+/// Check if an operation is a set predicate (multiple values)
+ICEBERG_EXPORT bool IsSetOperation(Expression::Operation op);
+
 }  // namespace iceberg