chore: import upstream snapshot with attribution

server/ast/create_index.go

@@ -0,0 +1,79 @@
+// 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 (
+	"strings"
+
+	"github.com/cockroachdb/errors"
+	vitess "github.com/dolthub/vitess/go/vt/sqlparser"
+
+	"github.com/dolthub/doltgresql/postgres/parser/sem/tree"
+)
+
+// nodeCreateIndex handles *tree.CreateIndex nodes.
+func nodeCreateIndex(ctx *Context, node *tree.CreateIndex) (*vitess.AlterTable, error) {
+	if node == nil {
+		return nil, nil
+	}
+	if node.Concurrently {
+		return nil, errors.Errorf("concurrent index creation is not yet supported")
+	}
+	if node.Using != "" && strings.ToLower(node.Using) != "btree" {
+		return nil, errors.Errorf("index method %s is not yet supported", node.Using)
+	}
+	indexDef, err := nodeIndexTableDef(ctx, &tree.IndexTableDef{
+		Name:        node.Name,
+		Columns:     node.Columns,
+		IndexParams: node.IndexParams,
+	})
+	if err != nil {
+		return nil, err
+	}
+	tableName, err := nodeTableName(ctx, &node.Table)
+	if err != nil {
+		return nil, err
+	}
+	var indexType string
+	if node.Unique {
+		indexType = vitess.UniqueStr
+	}
+	var predicate vitess.Expr
+	if node.Predicate != nil {
+		predicate, err = nodeExpr(ctx, node.Predicate)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return &vitess.AlterTable{
+		Table: tableName,
+		Statements: []*vitess.DDL{
+			{
+				Action:      vitess.AlterStr,
+				Table:       tableName,
+				IfNotExists: node.IfNotExists,
+				IndexSpec: &vitess.IndexSpec{
+					Action:    vitess.CreateStr,
+					FromName:  indexDef.Info.Name,
+					ToName:    indexDef.Info.Name,
+					Type:      indexType,
+					Fields:    indexDef.Fields,
+					Options:   indexDef.Options,
+					Predicate: predicate,
+				},
+			},
+		},
+	}, nil
+}