chore: import upstream snapshot with attribution

server/plpgsql/parse.go

@@ -0,0 +1,52 @@
+// Copyright 2025 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 plpgsql
+
+import (
+	"encoding/json"
+
+	"github.com/cockroachdb/errors"
+	pg_query "github.com/dolthub/pg_query_go/v6"
+)
+
+// Parse parses the given CREATE FUNCTION string (which must be the entire string, not just the body) into a Block
+// containing the contents of the body.
+func Parse(fullCreateFunctionString string) ([]InterpreterOperation, error) {
+	var functions []function
+	parsedBody, err := pg_query.ParsePlPgSqlToJSON(fullCreateFunctionString)
+	if err != nil {
+		return nil, err
+	}
+	err = json.Unmarshal([]byte(parsedBody), &functions)
+	if err != nil {
+		return nil, err
+	}
+	if len(functions) != 1 {
+		return nil, errors.New("CREATE FUNCTION parsed multiple blocks")
+	}
+	block, err := jsonConvert(functions[0].Function)
+	if err != nil {
+		return nil, err
+	}
+	ops := make([]InterpreterOperation, 0, len(block.Body)+len(block.Variables))
+	stack := NewInterpreterStack(nil)
+	if err = block.AppendOperations(&ops, &stack); err != nil {
+		return nil, err
+	}
+	if err = reconcileLabels(ops); err != nil {
+		return nil, err
+	}
+	return ops, nil
+}