csharp/src/Apache.Arrow/Types/StructType.cs

// Licensed to the Apache Software Foundation (ASF) under one or more
// contributor license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright ownership.
// The ASF licenses this file to You 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.

using System;
using System.Collections.Generic;
using System.Linq;

namespace Apache.Arrow.Types
{
    public sealed class StructType : ArrowType
    {
        private readonly List<Field> _fields;

        public override ArrowTypeId TypeId => ArrowTypeId.Struct;
        public override string Name => "struct";

        public IEnumerable<Field> Fields => _fields;

        public StructType(IEnumerable<Field> fields)
        {
            _fields = fields?.ToList();
        }

        public Field GetFieldByName(string name,
            IEqualityComparer<string> comparer = default)
        {
            if (comparer == null)
                comparer = StringComparer.Ordinal;

            return Fields.FirstOrDefault(
                field => comparer.Equals(field.Name, name));
        }

        public int GetFieldIndex(string name,
            IEqualityComparer<string> comparer = default)
        {
            if (comparer == null)
                comparer = StringComparer.Ordinal;

            // TODO: Consider caching field index if this method is in hot path.

            return _fields.FindIndex(
                field => comparer.Equals(field.Name, name));
        }

        public override void Accept(IArrowTypeVisitor visitor) => Accept(this, visitor);
    }
}