ParserCalculator.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ParserCalculator
{
    enum TokenType
    {
        UNDEFINED,
        ALPHA,
        NUMERIC,
        SPECIAL,
        BRACKET,
        QUOTE,
        QSTR
    }
    class Token
    {
        public TokenType type{get;set;}
        public string data{get;set;}
    }
    class Parser{
        
        public List<Token> toks = new List<Token>();
        Token t;


        char[] alpha = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_".ToCharArray();
        char[] numerics = "0123456789.".ToCharArray();
        char[] specials = "!#%^&*(-=,/\\;++".ToCharArray(); //@$
        char[] brackets = "()[]<>{}".ToCharArray();
        char[] quot="\"'".ToCharArray();
        char curquot = '\0';
        void BeginToken(char c)
        {
            if(quot.Contains(c)){
                t = new Token();
                t.type=TokenType.QUOTE;
                t.data=c.ToString();
                EndToken();
                t = new Token();
                t.type=TokenType.QSTR;
                t.data="";
                curquot = c;
            }else if (specials.Contains(c)){
                t = new Token();
                t.type = TokenType.SPECIAL;
                t.data = c.ToString();                
            }else if (brackets.Contains(c)){
                t = new Token();
                t.type = TokenType.BRACKET;
                t.data = c.ToString();
                EndToken();
                t = null;
            }
            else if (numerics.Contains(c))
            {
                t = new Token();
                t.type = TokenType.NUMERIC;
                t.data = c.ToString();
            }
            else if(alpha.Contains(c))
            {
                t = new Token();
                t.type = TokenType.ALPHA;
                t.data = c.ToString();
            }
        }
        void AppendToToken(char c){
            t.data += c.ToString();
        }
        void EndToken()
        {
            if(t!=null) toks.Add(t);
            if (t.type == TokenType.QSTR)
            {
                t = new Token();
                t.type = TokenType.QUOTE;
                t.data = curquot.ToString();
                EndToken();
            }
            t = null;
        }
        bool tokenbroken = true;
        public Parser(string s)
        {
            for (int i = 0; i < s.Length; i++)
            {
                if (Char.IsWhiteSpace(s[i]) && t!=null && t.type!=TokenType.QSTR)
                {
                    EndToken();
                    tokenbroken = true;
                    continue;
                }
                if (tokenbroken)
                {
                    BeginToken(s[i]);
                    tokenbroken = false;
                }
                else
                {
                    if (t == null)
                    {
                        BeginToken(s[i]);
                    }
                    else switch (t.type)
                    {
                        case TokenType.ALPHA:
                            if (alpha.Contains(s[i]))
                            {
                                AppendToToken(s[i]);
                            }
                            else
                            {
                                EndToken();
                                BeginToken(s[i]);
                            }
                            break;
                        case TokenType.NUMERIC:
                            if (numerics.Contains(s[i]))
                            {
                                AppendToToken(s[i]);
                            }
                            else
                            {
                                EndToken();
                                BeginToken(s[i]);
                            }
                            break;
                        case TokenType.SPECIAL:
                            if (specials.Contains(s[i]))
                            {
                                AppendToToken(s[i]);
                            }
                            else
                            {
                                EndToken();
                                BeginToken(s[i]);
                            }
                            break;
                        case TokenType.QSTR:
                            if (s[i] == curquot)
                                EndToken();
                            else AppendToToken(s[i]);
                            break;
                            
                    }
                }
            }
            if (t!=null) EndToken();
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            string line = Console.ReadLine();
            Parser p = new Parser(line);
            foreach(var tok in p.toks){
                Console.WriteLine("{0}:'{1}'", tok.type.ToString(), tok.data);
            }
        }
    }
}