chore: import upstream snapshot with attribution

server/ast/with.go

@@ -0,0 +1,80 @@
+// Copyright 2023 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 ast
+
+import (
+	"github.com/cockroachdb/errors"
+
+	"github.com/dolthub/doltgresql/postgres/parser/sem/tree"
+
+	vitess "github.com/dolthub/vitess/go/vt/sqlparser"
+)
+
+// nodeWith handles *tree.CTE nodes.
+func nodeCTE(ctx *Context, node *tree.CTE) (*vitess.CommonTableExpr, error) {
+	if node == nil {
+		return nil, nil
+	}
+
+	alias := vitess.NewTableIdent(string(node.Name.Alias))
+	cols := make([]vitess.ColIdent, len(node.Name.Cols))
+	for i, col := range node.Name.Cols {
+		cols[i] = vitess.NewColIdent(string(col))
+	}
+
+	subSelect, ok := node.Stmt.(*tree.Select)
+	if !ok {
+		return nil, errors.Errorf("unsupported CTE statement type: %T", node.Stmt)
+	}
+
+	selectStmt, err := nodeSelect(ctx, subSelect)
+	if err != nil {
+		return nil, err
+	}
+
+	subQuery := &vitess.Subquery{
+		Select: selectStmt,
+	}
+
+	return &vitess.CommonTableExpr{
+		AliasedTableExpr: &vitess.AliasedTableExpr{
+			Expr: subQuery,
+			As:   alias,
+			Auth: vitess.AuthInformation{AuthType: vitess.AuthType_IGNORE},
+		},
+		Columns: cols,
+	}, nil
+}
+
+// nodeWith handles *tree.With nodes.
+func nodeWith(ctx *Context, node *tree.With) (*vitess.With, error) {
+	if node == nil {
+		return nil, nil
+	}
+
+	ctes := make([]*vitess.CommonTableExpr, len(node.CTEList))
+	for i, cte := range node.CTEList {
+		var err error
+		ctes[i], err = nodeCTE(ctx, cte)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return &vitess.With{
+		Recursive: node.Recursive,
+		Ctes:      ctes,
+	}, nil
+}