feat: implement expression evaluator

Author: wgtmac

src/iceberg/CMakeLists.txt

@@ -21,6 +21,7 @@ set(ICEBERG_SOURCES
     arrow_c_data_guard_internal.cc
     catalog/memory/in_memory_catalog.cc
     expression/binder.cc
+    expression/evaluator.cc
     expression/expression.cc
     expression/expressions.cc
     expression/literal.cc

src/iceberg/expression/evaluator.cc

@@ -0,0 +1,163 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#include "iceberg/expression/evaluator.h"
+
+#include "iceberg/expression/binder.h"
+#include "iceberg/expression/expression_visitor.h"
+#include "iceberg/schema.h"
+#include "iceberg/util/macros.h"
+
+namespace iceberg {
+
+class Evaluator::EvalVisitor : public BoundVisitor<bool> {
+ public:
+  void UpdateRow(const StructLike* row) { row_ = row; }
+
+  Result<bool> AlwaysTrue() override { return true; }
+
+  Result<bool> AlwaysFalse() override { return false; }
+
+  Result<bool> Not(bool child_result) override { return !child_result; }
+
+  Result<bool> And(bool left_result, bool right_result) override {
+    return left_result && right_result;
+  }
+
+  Result<bool> Or(bool left_result, bool right_result) override {
+    return left_result || right_result;
+  }
+
+  Result<bool> IsNull(const std::shared_ptr<BoundTerm>& term) override {
+    ICEBERG_DCHECK(row_, "Row is not set");
+    ICEBERG_ASSIGN_OR_RAISE(auto value, term->Evaluate(*row_));
+    return value.IsNull();
+  }
+
+  Result<bool> NotNull(const std::shared_ptr<BoundTerm>& term) override {
+    ICEBERG_DCHECK(row_, "Row is not set");
+    ICEBERG_ASSIGN_OR_RAISE(auto value, term->Evaluate(*row_));
+    return !value.IsNull();
+  }
+
+  Result<bool> IsNaN(const std::shared_ptr<BoundTerm>& term) override {
+    ICEBERG_DCHECK(row_, "Row is not set");
+    ICEBERG_ASSIGN_OR_RAISE(auto value, term->Evaluate(*row_));
+    return value.IsNaN();
+  }
+
+  Result<bool> NotNaN(const std::shared_ptr<BoundTerm>& term) override {
+    ICEBERG_DCHECK(row_, "Row is not set");
+    ICEBERG_ASSIGN_OR_RAISE(auto value, term->Evaluate(*row_));
+    return !value.IsNaN();
+  }
+
+  Result<bool> Lt(const std::shared_ptr<BoundTerm>& term, const Literal& lit) override {
+    ICEBERG_DCHECK(row_, "Row is not set");
+    ICEBERG_ASSIGN_OR_RAISE(auto value, term->Evaluate(*row_));
+    return value < lit;
+  }
+
+  Result<bool> LtEq(const std::shared_ptr<BoundTerm>& term, const Literal& lit) override {
+    ICEBERG_DCHECK(row_, "Row is not set");
+    ICEBERG_ASSIGN_OR_RAISE(auto value, term->Evaluate(*row_));
+    return value <= lit;
+  }
+
+  Result<bool> Gt(const std::shared_ptr<BoundTerm>& term, const Literal& lit) override {
+    ICEBERG_DCHECK(row_, "Row is not set");
+    ICEBERG_ASSIGN_OR_RAISE(auto value, term->Evaluate(*row_));
+    return value > lit;
+  }
+
+  Result<bool> GtEq(const std::shared_ptr<BoundTerm>& term, const Literal& lit) override {
+    ICEBERG_DCHECK(row_, "Row is not set");
+    ICEBERG_ASSIGN_OR_RAISE(auto value, term->Evaluate(*row_));
+    return value >= lit;
+  }
+
+  Result<bool> Eq(const std::shared_ptr<BoundTerm>& term, const Literal& lit) override {
+    ICEBERG_DCHECK(row_, "Row is not set");
+    ICEBERG_ASSIGN_OR_RAISE(auto value, term->Evaluate(*row_));
+    return value == lit;
+  }
+
+  Result<bool> NotEq(const std::shared_ptr<BoundTerm>& term,
+                     const Literal& lit) override {
+    ICEBERG_ASSIGN_OR_RAISE(auto eq_result, Eq(term, lit));
+    return !eq_result;
+  }
+
+  Result<bool> In(const std::shared_ptr<BoundTerm>& term,
+                  const BoundSetPredicate::LiteralSet& literal_set) override {
+    ICEBERG_DCHECK(row_, "Row is not set");
+    ICEBERG_ASSIGN_OR_RAISE(auto value, term->Evaluate(*row_));
+    return literal_set.contains(value);
+  }
+
+  Result<bool> NotIn(const std::shared_ptr<BoundTerm>& term,
+                     const BoundSetPredicate::LiteralSet& literal_set) override {
+    ICEBERG_ASSIGN_OR_RAISE(auto in_result, In(term, literal_set));
+    return !in_result;
+  }
+
+  Result<bool> StartsWith(const std::shared_ptr<BoundTerm>& term,
+                          const Literal& lit) override {
+    ICEBERG_DCHECK(row_, "Row is not set");
+    ICEBERG_ASSIGN_OR_RAISE(auto value, term->Evaluate(*row_));
+
+    // Both value and literal should be strings
+    if (!std::holds_alternative<std::string>(value.value()) ||
+        !std::holds_alternative<std::string>(lit.value())) {
+      return false;
+    }
+
+    const auto& str_value = std::get<std::string>(value.value());
+    const auto& str_prefix = std::get<std::string>(lit.value());
+    return str_value.starts_with(str_prefix);
+  }
+
+  Result<bool> NotStartsWith(const std::shared_ptr<BoundTerm>& term,
+                             const Literal& lit) override {
+    ICEBERG_ASSIGN_OR_RAISE(auto starts_result, StartsWith(term, lit));
+    return !starts_result;
+  }
+
+ private:
+  const StructLike* row_{nullptr};
+};
+
+Evaluator::Evaluator(std::shared_ptr<Expression> bound_expr)
+    : bound_expr_(std::move(bound_expr)), visitor_(std::make_unique<EvalVisitor>()) {}
+
+Evaluator::~Evaluator() = default;
+
+Result<std::unique_ptr<Evaluator>> Evaluator::Make(const Schema& schema,
+                                                   std::shared_ptr<Expression> unbound,
+                                                   bool case_sensitive) {
+  ICEBERG_ASSIGN_OR_RAISE(auto bound_expr, Binder::Bind(schema, unbound, case_sensitive));
+  return std::unique_ptr<Evaluator>(new Evaluator(std::move(bound_expr)));
+}
+
+Result<bool> Evaluator::Eval(const StructLike& row) const {
+  visitor_->UpdateRow(&row);
+  return Visit<bool, EvalVisitor>(bound_expr_, *visitor_);
+}
+
+}  // namespace iceberg

src/iceberg/expression/evaluator.h

@@ -0,0 +1,67 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#pragma once
+
+/// \file iceberg/expression/evaluator.h
+/// Evaluator for checking if a data row matches a bound expression.
+
+#include <memory>
+
+#include "iceberg/iceberg_export.h"
+#include "iceberg/result.h"
+#include "iceberg/type_fwd.h"
+
+namespace iceberg {
+
+/// \brief Evaluates an Expression against data rows.
+///
+/// This class evaluates bound expressions against StructLike data rows to determine
+/// if the row matches the expression criteria. The evaluator binds unbound expressions
+/// to a schema on construction and then can be used to evaluate multiple data rows.
+///
+/// Thread-safe: Yes, the evaluator is immutable after construction.
+class ICEBERG_EXPORT Evaluator {
+ public:
+  /// \brief Make an evaluator for an unbound expression.
+  ///
+  /// \param schema The schema to bind against
+  /// \param unbound The unbound expression to evaluate
+  /// \param case_sensitive Whether field name matching is case-sensitive
+  static Result<std::unique_ptr<Evaluator>> Make(const Schema& schema,
+                                                 std::shared_ptr<Expression> unbound,
+                                                 bool case_sensitive = true);
+
+  ~Evaluator();
+
+  /// \brief Evaluate the expression against a data row.
+  ///
+  /// \param row The data row to evaluate
+  /// \return true if the row matches the expression, false otherwise, or error
+  Result<bool> Eval(const StructLike& row) const;
+
+ private:
+  explicit Evaluator(std::shared_ptr<Expression> bound_expr);
+
+  class EvalVisitor;
+  std::shared_ptr<Expression> bound_expr_;
+  std::unique_ptr<EvalVisitor> visitor_;
+};
+
+}  // namespace iceberg

src/iceberg/expression/literal.cc

@@ -504,6 +504,11 @@ bool Literal::IsAboveMax() const { return std::holds_alternative<AboveMax>(value
 
 bool Literal::IsNull() const { return std::holds_alternative<std::monostate>(value_); }
 
+bool Literal::IsNaN() const {
+  return std::holds_alternative<float>(value_) && std::isnan(std::get<float>(value_)) ||
+         std::holds_alternative<double>(value_) && std::isnan(std::get<double>(value_));
+}
+
 // LiteralCaster implementation
 
 Result<Literal> LiteralCaster::CastTo(const Literal& literal,

src/iceberg/expression/literal.h

@@ -154,6 +154,10 @@ class ICEBERG_EXPORT Literal : public util::Formattable {
   /// \return true if this literal is null, false otherwise
   bool IsNull() const;
 
+  /// Check if this literal is NaN.
+  /// \return true if this literal is NaN, false otherwise
+  bool IsNaN() const;
+
   std::string ToString() const override;
 
  private:

src/iceberg/expression/predicate.cc

@@ -50,6 +50,10 @@ Result<std::unique_ptr<UnboundPredicateImpl<B>>> UnboundPredicateImpl<B>::Make(
   if (!term) [[unlikely]] {
     return InvalidExpression("UnboundPredicate cannot have null term");
   }
+  if (op == Expression::Operation::kIn || op == Expression::Operation::kNotIn) {
+    return InvalidExpression("Cannot create {} predicate without a value",
+                             ::iceberg::ToString(op));
+  }
   return std::unique_ptr<UnboundPredicateImpl<B>>(
       new UnboundPredicateImpl<B>(op, std::move(term)));
 }
@@ -71,6 +75,11 @@ Result<std::unique_ptr<UnboundPredicateImpl<B>>> UnboundPredicateImpl<B>::Make(
   if (!term) [[unlikely]] {
     return InvalidExpression("UnboundPredicate cannot have null term");
   }
+  if (values.empty() &&
+      (op == Expression::Operation::kIn || op == Expression::Operation::kNotIn)) {
+    return InvalidExpression("Cannot create {} predicate without a value",
+                             ::iceberg::ToString(op));
+  }
   return std::unique_ptr<UnboundPredicateImpl<B>>(
       new UnboundPredicateImpl<B>(op, std::move(term), std::move(values)));
 }
@@ -183,16 +192,6 @@ bool IsFloatingType(TypeId type) {
   return type == TypeId::kFloat || type == TypeId::kDouble;
 }
 
-bool IsNan(const Literal& literal) {
-  const auto& value = literal.value();
-  if (std::holds_alternative<float>(value)) {
-    return std::isnan(std::get<float>(value));
-  } else if (std::holds_alternative<double>(value)) {
-    return std::isnan(std::get<double>(value));
-  }
-  return false;
-}
-
 bool StartsWith(const Literal& lhs, const Literal& rhs) {
   const auto& lhs_value = lhs.value();
   const auto& rhs_value = rhs.value();
@@ -383,9 +382,9 @@ Result<bool> BoundUnaryPredicate::Test(const Literal& literal) const {
     case Expression::Operation::kNotNull:
       return !literal.IsNull();
     case Expression::Operation::kIsNan:
-      return IsNan(literal);
+      return literal.IsNaN();
     case Expression::Operation::kNotNan:
-      return !IsNan(literal);
+      return !literal.IsNaN();
     default:
       return InvalidExpression("Invalid operation for BoundUnaryPredicate: {}", op());
   }

src/iceberg/expression/predicate.h

@@ -133,6 +133,8 @@ class ICEBERG_EXPORT UnboundPredicateImpl : public UnboundPredicate,
 
   Result<std::shared_ptr<Expression>> Negate() const override;
 
+  std::span<const Literal> literals() const { return values_; }
+
  private:
   UnboundPredicateImpl(Expression::Operation op, std::shared_ptr<UnboundTerm<B>> term);
   UnboundPredicateImpl(Expression::Operation op, std::shared_ptr<UnboundTerm<B>> term,

src/iceberg/expression/term.cc

@@ -59,7 +59,7 @@ NamedReference::~NamedReference() = default;
 Result<std::shared_ptr<BoundReference>> NamedReference::Bind(const Schema& schema,
                                                              bool case_sensitive) const {
   ICEBERG_ASSIGN_OR_RAISE(auto field_opt,
-                          schema.GetFieldByName(field_name_, case_sensitive));
+                          schema.FindFieldByName(field_name_, case_sensitive));
   if (!field_opt.has_value()) [[unlikely]] {
     return InvalidExpression("Cannot find field '{}' in struct: {}", field_name_,
                              schema.ToString());

src/iceberg/meson.build

@@ -43,6 +43,7 @@ iceberg_sources = files(
     'arrow_c_data_guard_internal.cc',
     'catalog/memory/in_memory_catalog.cc',
     'expression/binder.cc',
+    'expression/evaluator.cc',
     'expression/expression.cc',
     'expression/expressions.cc',
     'expression/literal.cc',

src/iceberg/test/CMakeLists.txt

@@ -145,6 +145,7 @@ if(ICEBERG_BUILD_BUNDLE)
                    USE_BUNDLE
                    SOURCES
                    eval_expr_test.cc
+                   evaluator_test.cc
                    test_common.cc)
 
   add_iceberg_test(parquet_test