tweets.csv からラ抜き言葉が含まれているツイートを検出して出力するコード

RanukiCheckerConsole.cs

using LINQtoCSV;
using NMeCab;
using System.Collections.Generic;

namespace RanukiCheckerConsole
{
    class Program
    {
        static void Main(string[] args)
        {
            var fileName = "tweets.csv";

            var inputFileDescription = new CsvFileDescription
            {
                SeparatorChar = ',',
                EnforceCsvColumnAttribute = true,
                FirstLineHasColumnNames = true
            };

            var context = new CsvContext();
            var tweets = context.Read<TweetsCsv>(fileName, inputFileDescription);

            // RT を削除
            //            tweets = tweets.Where(s => !string.IsNullOrWhiteSpace(RetweetedStatusId));

            var mecab = MeCabTagger.Create();

            var ranukiList = new List<TweetsCsv>();

            /*
             * UniDic フォーマット
             *
             *   1.品詞大分類
             *   2.品詞中分類
             *   3.品詞小分類
             *   4.品詞細分類
             *   5.活用型
             *   6.活用形
             *   7.語彙素読み
             *   8.語彙素（語彙素表記 + 語彙素細分類）
             *   9.書字形出現形
             *   10.発音形出現形
             *   11.書字形基本形
             *   12.発音形基本形
             *   13.語種
             *
             */

            // 特徴(Feature)を分割した配列のどこに何が入るかを示す定数
            // 出力フォーマットによって変える
            const int InflectedForm = 4; //活用型
            const int Conjugate = 5; // 活用形
            const int LexemeReading = 6; // 語彙素読み

            foreach (var tweet in tweets)
            {
                var node = mecab.ParseToNode(tweet.Text);

                bool checkFlag = false;

                while (node != null)
                {
                    var features = node.Feature.Split(',');

                    if (checkFlag && features[LexemeReading] == "れる")
                    {
                        ranukiList.Add(tweet);
                        break;
                    }

                    if (features[InflectedForm] == "一段" && features[Conjugate] == "未然形")
                    {
                        checkFlag = true;
                    }
                    // カ変も判定しようとしてみる
                    //                    else if (features[InflectedForm].StartsWith("カ変") && features[Conjugate] == "未然形")
                    //                    {
                    //                        checkFlag = true;
                    //                    }
                    else
                    {
                        checkFlag = false;
                    }

                    node = node.Next;
                }

                checkFlag = false;
            }

            context.Write(ranukiList, "ranuki_tweets.csv");
        }
    }
}

TweetsCsv.cs

using LINQtoCSV;

namespace RanukiCheckerConsole
{
    public class TweetsCsv
    {
        [CsvColumn(FieldIndex = 1, Name = "tweet_id")]
        public string Id { get; set; }

        [CsvColumn(FieldIndex = 2, Name = "in_reply_to_status_id", CanBeNull = true)]
        public string InReplyToStatusId { get; set; }

        [CsvColumn(FieldIndex = 3, Name = "in_reply_to_user_id", CanBeNull = true)]
        public string InReplyToUserId { get; set; }

        [CsvColumn(FieldIndex = 4, Name = "timestamp", CanBeNull = true)]
        public string TimeStamp { get; set; }

        [CsvColumn(FieldIndex = 5, Name = "source", CanBeNull = true)]
        public string Source { get; set; }

        [CsvColumn(FieldIndex = 6, Name = "text", CanBeNull = true)]
        public string Text { get; set; }

        [CsvColumn(FieldIndex = 7, Name = "retweeted_status_id", CanBeNull = true)]
        public string RetweetedStatusId { get; set; }

        [CsvColumn(FieldIndex = 8, Name = "retweeted_status_user_id", CanBeNull = true)]
        public string RetweetedStatusUserId { get; set; }

        [CsvColumn(FieldIndex = 9, Name = "retweeted_status_timestamp", CanBeNull = true)]
        public string RetweetedStatusUserIdTimeStamp { get; set; }

        [CsvColumn(FieldIndex = 10, Name = "expanded_urls", CanBeNull = true)]
        public string ExpandedUrls { get; set; }
    }
}