chore: import upstream snapshot with attribution

server/node/return.go

@@ -0,0 +1,115 @@
+// Copyright 2026 Dolthub, Inc.
+//
+// Licensed 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.
+
+package node
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/cockroachdb/errors"
+	"github.com/dolthub/go-mysql-server/sql"
+	vitess "github.com/dolthub/vitess/go/vt/sqlparser"
+)
+
+// Return represents the statement RETURN statement.
+type Return struct {
+	Expr     sql.Expression
+	exprStmt string
+}
+
+var _ sql.ExecSourceRel = (*Return)(nil)
+var _ sql.Expressioner = (*Return)(nil)
+var _ vitess.Injectable = (*Return)(nil)
+
+// NewReturn creates a new *Return node.
+func NewReturn(exprStmt string) *Return {
+	return &Return{
+		Expr:     nil,
+		exprStmt: exprStmt,
+	}
+}
+
+// Children implements the interface sql.ExecSourceRel.
+func (r *Return) Children() []sql.Node {
+	return nil
+}
+
+// IsReadOnly implements the interface sql.ExecSourceRel.
+func (r *Return) IsReadOnly() bool {
+	return true
+}
+
+// Resolved implements the interface sql.ExecSourceRel.
+func (r *Return) Resolved() bool {
+	if r.Expr == nil {
+		return false
+	}
+	return !r.Expr.Resolved()
+}
+
+// RowIter implements the interface sql.ExecSourceRel.
+func (r *Return) RowIter(ctx *sql.Context, row sql.Row) (sql.RowIter, error) {
+	return nil, errors.Errorf(`cannot call RowIter on Return node`)
+}
+
+// String implements the interface sql.ExecSourceRel.
+func (r *Return) String() string {
+	if r.Expr == nil {
+		return fmt.Sprintf("RETURN %s", r.exprStmt)
+	}
+	return fmt.Sprintf("RETURN %s", r.Expr.String())
+}
+
+// Schema implements the interface sql.ExecSourceRel.
+func (r *Return) Schema(ctx *sql.Context) sql.Schema {
+	return sql.Schema{
+		{Name: r.Expr.String(), Type: r.Expr.Type(ctx), Source: ""},
+	}
+}
+
+// WithChildren implements the interface sql.ExecSourceRel.
+func (r *Return) WithChildren(ctx *sql.Context, children ...sql.Node) (sql.Node, error) {
+	if len(children) != 0 {
+		return nil, sql.ErrInvalidChildrenNumber.New(r, len(children), 0)
+	}
+	return r, nil
+}
+
+// WithResolvedChildren implements the interface sql.ExecSourceRel.
+func (r *Return) WithResolvedChildren(ctx context.Context, children []any) (any, error) {
+	if len(children) != 1 {
+		return nil, sql.ErrInvalidChildrenNumber.New(r, len(children), 1)
+	}
+
+	nr := *r
+	nr.Expr = children[0].(sql.Expression)
+	return &nr, nil
+}
+
+// Expressions implements the interface sql.Expressioner.
+func (r *Return) Expressions() []sql.Expression {
+	return []sql.Expression{r.Expr}
+}
+
+// WithExpressions implements the interface sql.Expressioner.
+func (r *Return) WithExpressions(ctx *sql.Context, exprs ...sql.Expression) (sql.Node, error) {
+	if len(exprs) != 1 {
+		return nil, sql.ErrInvalidChildrenNumber.New(r, len(exprs), 1)
+	}
+
+	nr := *r
+	nr.Expr = exprs[0]
+	return &nr, nil
+}