C#实现LL(1)文法判断及FIRST、FOLLOW集计算与展示

using System;
using System.Collections.Generic;
using System.Text.RegularExpressions;
using System.Windows.Forms;

namespace LL1GrammarAnalyzer
{
    public partial class Form1 : Form
    {
        // ... 其他代码 ...

        private void button4_Click(object sender, EventArgs e)
        {
            string text = richTextBox1.Text;
            production = new Dictionary<string, List<string>>();
            string[] pro = text.Split('
');
            foreach (string s in pro)
            {
                if (s == '') continue;

                Regex.Replace(s, ' ', '');
                string[] ga = Regex.Split(s, '->');
                if (ga.Length != 2) return;
                if (ga[0].Length == 0 || ga[1].Length == 0)
                    return;
                if (ga[0].Length != 1 || !char.IsUpper(ga[0][0])) return;

                string[] ga2 = Regex.Split(ga[1], '\|');
                if (!production.ContainsKey(ga[0]))
                    production.Add(ga[0], new List<string>());
                foreach (string s1 in ga2)
                    production[ga[0]].Add(s1);
            }

            firsts = new Dictionary<string, List<string>>();
            foreach (var item in production.Keys)
                GetFirst(item, production, firsts);

            follows = new Dictionary<string, List<string>>();
            foreach (var item in production.Keys)
                GetFollow(item, production, firsts, follows);

            if (JudgeLL1(production, firsts, follows))
            {
                MessageBox.Show('该文法是LL(1)文法\n');
                
            }
            else
            {
                MessageBox.Show('该文法不是LL(1)文法，存在左递归或者存在FIRST集合有交集的情况！\n');
            }
            button1.Enabled = true;
            button2.Enabled = true;
            button3.Enabled = true;
        }

        // ... 其他代码 ...

        private void button1_Click(object sender, EventArgs e)
        {
            listView1.Clear();
            listView1.Columns.Add('', 30);
            foreach (var item in terminals)
            {
                listView1.Columns.Add(item, 30);
            }
            foreach (var item in nonterminals)
            {
                ListViewItem lvi = new ListViewItem(item);
                lvi.SubItems.Add('');
                foreach (var t in terminals)
                {
                    if (firsts[item].Contains(t))
                    {
                        lvi.SubItems.Add('1');
                    }
                    else
                    {
                        lvi.SubItems.Add('0');
                    }
                }
                listView1.Items.Add(lvi);
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            listView2.Clear();
            listView2.Columns.Add('', 30);
            foreach (var item in terminals)
            {
                listView2.Columns.Add(item, 30);
            }
            foreach (var item in nonterminals)
            {
                ListViewItem lvi = new ListViewItem(item);
                lvi.SubItems.Add('');
                foreach (var t in terminals)
                {
                    if (follows[item].Contains(t))
                    {
                        lvi.SubItems.Add('1');
                    }
                    else
                    {
                        lvi.SubItems.Add('0');
                    }
                }
                listView2.Items.Add(lvi);
            }
        }

        // ... 其他代码 ...
    }
}