ESQL: Squash Order

This merges the esql-core version of `Order` into the esql-proper
version of `Order`. Now that we've forked from ql we can simplify this
so you only have to read one thing.

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/analysis/PreAnalyzer.java

@@ -7,7 +7,6 @@
 
 package org.elasticsearch.xpack.esql.analysis;
 
-import org.elasticsearch.xpack.esql.core.analyzer.TableInfo;
 import org.elasticsearch.xpack.esql.plan.logical.Enrich;
 import org.elasticsearch.xpack.esql.plan.logical.LogicalPlan;
 import org.elasticsearch.xpack.esql.plan.logical.UnresolvedRelation;

x-pack/plugin/esql-core/src/main/java/org/elasticsearch/xpack/esql/core/analyzer/TableInfo.java → x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/analysis/TableInfo.java

@@ -5,7 +5,7 @@
  * 2.0.
  */
 
-package org.elasticsearch.xpack.esql.core.analyzer;
+package org.elasticsearch.xpack.esql.analysis;
 
 import org.elasticsearch.xpack.esql.core.plan.TableIdentifier;
 

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/Order.java

@@ -11,58 +11,127 @@
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.xpack.esql.core.expression.Expression;
+import org.elasticsearch.xpack.esql.core.expression.Nullability;
 import org.elasticsearch.xpack.esql.core.tree.NodeInfo;
 import org.elasticsearch.xpack.esql.core.tree.Source;
 import org.elasticsearch.xpack.esql.core.type.DataType;
 import org.elasticsearch.xpack.esql.io.stream.PlanStreamInput;
 
 import java.io.IOException;
 import java.util.List;
+import java.util.Objects;
 
-public class Order extends org.elasticsearch.xpack.esql.core.expression.Order {
+import static org.elasticsearch.xpack.esql.core.expression.TypeResolutions.isExact;
+
+public class Order extends Expression {
     public static final NamedWriteableRegistry.Entry ENTRY = new NamedWriteableRegistry.Entry(Expression.class, "Order", Order::new);
 
+    public enum OrderDirection {
+        ASC,
+        DESC
+    }
+
+    public enum NullsPosition {
+        FIRST,
+        LAST,
+        /**
+         * Nulls position has not been specified by the user and an appropriate default will be used.
+         *
+         * The default values are chosen such that it stays compatible with previous behavior. Unfortunately, this results in
+         * inconsistencies across different types of queries (see https://github.com/elastic/elasticsearch/issues/77068).
+         */
+        ANY;
+    }
+
+    private final Expression child;
+    private final OrderDirection direction;
+    private final NullsPosition nulls;
+
     public Order(Source source, Expression child, OrderDirection direction, NullsPosition nulls) {
-        super(source, child, direction, nulls);
+        super(source, List.of(child));
+        this.child = child;
+        this.direction = direction;
+        this.nulls = nulls == null ? NullsPosition.ANY : nulls;
     }
 
     public Order(StreamInput in) throws IOException {
         this(
             Source.readFrom((PlanStreamInput) in),
             in.readNamedWriteable(Expression.class),
-            in.readEnum(org.elasticsearch.xpack.esql.core.expression.Order.OrderDirection.class),
-            in.readEnum(org.elasticsearch.xpack.esql.core.expression.Order.NullsPosition.class)
+            in.readEnum(Order.OrderDirection.class),
+            in.readEnum(Order.NullsPosition.class)
         );
     }
 
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         Source.EMPTY.writeTo(out);
-        out.writeNamedWriteable(child());
-        out.writeEnum(direction());
-        out.writeEnum(nullsPosition());
+        out.writeNamedWriteable(child);
+        out.writeEnum(direction);
+        out.writeEnum(nulls);
     }
 
     @Override
     public String getWriteableName() {
         return ENTRY.name;
     }
 
+    public Expression child() {
+        return child;
+    }
+
+    public OrderDirection direction() {
+        return direction;
+    }
+
+    public NullsPosition nullsPosition() {
+        return nulls;
+    }
+
     @Override
     protected TypeResolution resolveType() {
-        if (DataType.isString(child().dataType())) {
+        if (DataType.isString(child.dataType())) {
             return TypeResolution.TYPE_RESOLVED;
         }
-        return super.resolveType();
+        return isExact(child, "ORDER BY cannot be applied to field of data type [{}]: {}");
+    }
+
+    @Override
+    public DataType dataType() {
+        return child.dataType();
     }
 
     @Override
     public Order replaceChildren(List<Expression> newChildren) {
-        return new Order(source(), newChildren.get(0), direction(), nullsPosition());
+        return new Order(source(), newChildren.get(0), direction, nulls);
+    }
+
+    @Override
+    protected NodeInfo<Order> info() {
+        return NodeInfo.create(this, Order::new, child, direction, nulls);
+    }
+
+    @Override
+    public Nullability nullable() {
+        return Nullability.FALSE;
     }
 
     @Override
-    protected NodeInfo<org.elasticsearch.xpack.esql.core.expression.Order> info() {
-        return NodeInfo.create(this, Order::new, child(), direction(), nullsPosition());
+    public int hashCode() {
+        return Objects.hash(child, direction, nulls);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+
+        if (obj == null || getClass() != obj.getClass()) {
+            return false;
+        }
+
+        Order other = (Order) obj;
+        return Objects.equals(direction, other.direction) && Objects.equals(nulls, other.nulls) && Objects.equals(child, other.child);
     }
 }

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/io/stream/PlanNamedTypes.java

@@ -24,10 +24,10 @@
 import org.elasticsearch.xpack.esql.core.expression.Expression;
 import org.elasticsearch.xpack.esql.core.expression.FieldAttribute;
 import org.elasticsearch.xpack.esql.core.expression.NamedExpression;
-import org.elasticsearch.xpack.esql.core.expression.Order;
 import org.elasticsearch.xpack.esql.core.index.EsIndex;
 import org.elasticsearch.xpack.esql.core.tree.Source;
 import org.elasticsearch.xpack.esql.core.type.EsField;
+import org.elasticsearch.xpack.esql.expression.Order;
 import org.elasticsearch.xpack.esql.plan.logical.Aggregate;
 import org.elasticsearch.xpack.esql.plan.logical.Dissect;
 import org.elasticsearch.xpack.esql.plan.logical.Dissect.Parser;

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/optimizer/LocalPhysicalPlanOptimizer.java

@@ -27,7 +27,6 @@
 import org.elasticsearch.xpack.esql.core.expression.Literal;
 import org.elasticsearch.xpack.esql.core.expression.MetadataAttribute;
 import org.elasticsearch.xpack.esql.core.expression.NamedExpression;
-import org.elasticsearch.xpack.esql.core.expression.Order;
 import org.elasticsearch.xpack.esql.core.expression.TypedAttribute;
 import org.elasticsearch.xpack.esql.core.expression.function.scalar.UnaryScalarFunction;
 import org.elasticsearch.xpack.esql.core.expression.predicate.Predicates;
@@ -47,6 +46,7 @@
 import org.elasticsearch.xpack.esql.core.util.Queries;
 import org.elasticsearch.xpack.esql.core.util.Queries.Clause;
 import org.elasticsearch.xpack.esql.core.util.StringUtils;
+import org.elasticsearch.xpack.esql.expression.Order;
 import org.elasticsearch.xpack.esql.expression.function.aggregate.Count;
 import org.elasticsearch.xpack.esql.expression.function.aggregate.SpatialAggregateFunction;
 import org.elasticsearch.xpack.esql.expression.function.scalar.ip.CIDRMatch;

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/optimizer/LogicalPlanOptimizer.java

@@ -15,10 +15,10 @@
 import org.elasticsearch.xpack.esql.core.expression.AttributeMap;
 import org.elasticsearch.xpack.esql.core.expression.Expression;
 import org.elasticsearch.xpack.esql.core.expression.Expressions;
-import org.elasticsearch.xpack.esql.core.expression.Order;
 import org.elasticsearch.xpack.esql.core.expression.ReferenceAttribute;
 import org.elasticsearch.xpack.esql.core.rule.ParameterizedRule;
 import org.elasticsearch.xpack.esql.core.rule.ParameterizedRuleExecutor;
+import org.elasticsearch.xpack.esql.expression.Order;
 import org.elasticsearch.xpack.esql.optimizer.rules.AddDefaultTopN;
 import org.elasticsearch.xpack.esql.optimizer.rules.BooleanFunctionEqualsElimination;
 import org.elasticsearch.xpack.esql.optimizer.rules.BooleanSimplification;

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/optimizer/rules/PruneLiteralsInOrderBy.java

@@ -7,7 +7,7 @@
 
 package org.elasticsearch.xpack.esql.optimizer.rules;
 
-import org.elasticsearch.xpack.esql.core.expression.Order;
+import org.elasticsearch.xpack.esql.expression.Order;
 import org.elasticsearch.xpack.esql.plan.logical.LogicalPlan;
 import org.elasticsearch.xpack.esql.plan.logical.OrderBy;
 

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/optimizer/rules/PruneRedundantSortClauses.java

@@ -8,7 +8,7 @@
 package org.elasticsearch.xpack.esql.optimizer.rules;
 
 import org.elasticsearch.xpack.esql.core.expression.ExpressionSet;
-import org.elasticsearch.xpack.esql.core.expression.Order;
+import org.elasticsearch.xpack.esql.expression.Order;
 import org.elasticsearch.xpack.esql.plan.logical.LogicalPlan;
 import org.elasticsearch.xpack.esql.plan.logical.OrderBy;
 

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/optimizer/rules/ReplaceOrderByExpressionWithEval.java

@@ -9,7 +9,7 @@
 
 import org.elasticsearch.xpack.esql.core.expression.Alias;
 import org.elasticsearch.xpack.esql.core.expression.Attribute;
-import org.elasticsearch.xpack.esql.core.expression.Order;
+import org.elasticsearch.xpack.esql.expression.Order;
 import org.elasticsearch.xpack.esql.plan.logical.Eval;
 import org.elasticsearch.xpack.esql.plan.logical.LogicalPlan;
 import org.elasticsearch.xpack.esql.plan.logical.OrderBy;