LL(1)文法判定工具 - 在线检测你的文法是否符合LL(1)条件

public partial class Form4 : Form { LL1Item LL1Item; First first; Follow follow;

public Form4()
{
    InitializeComponent();
}

//--------------------预处理

private void button3_Click(object sender, EventArgs e)
{
    richTextBox1.Text = "";
    OpenFileDialog openFileDialog1 = new OpenFileDialog();
    DialogResult dr = openFileDialog1.ShowDialog();
    string filename = openFileDialog1.FileName;//获取或设置一个包含在文件对话框中选定的文件名字符串
    if (dr == DialogResult.OK && !string.IsNullOrEmpty(filename))
    {
        StreamReader sr = new StreamReader(filename);
        richTextBox1.Text = sr.ReadToEnd();
        sr.Close();
    }
}

private void Form4_Load(object sender, EventArgs e)
{

}

private void button4_Click(object sender, EventArgs e)
{
    string text = richTextBox1.Text;
    LL1Item = new LL1Item(text);
    if (LL1Item.creatproduction() == 1)
    {
        first = new First(LL1Item);
        follow = new Follow(LL1Item, first);
        if (LL1Item.getisreach()["S"])
        {
            MessageBox.Show("该文法不是LL(1)文法，存在左递归的情况！\n");
        }
        else
        {
            bool flag = true;
            var selects = new Select(LL1Item, first, follow).getselects();
            foreach (var item in selects)
            {
                var value = item.Value;
                for (int i = 0; i < value.Count - 1; i++)
                    for (int j = i + 1; j < value.Count; j++)
                        if (value[i] == value[j])
                        {
                            flag = false;
                            break;
                        }
                if (!flag) break;
            }
            if (flag)
            {
                MessageBox.Show("该文法是LL(1)文法\n");
                foreach (var item in first.getfirsts())
                {
                    richTextBox2.AppendText(item.Key + ": { ");
                    foreach (var s in item.Value)
                        richTextBox2.AppendText(s + " ");
                    richTextBox2.AppendText("}\n");
                }
                richTextBox2.AppendText("FOLLOW集：\n");
                foreach (var item in follow.getfollows())
                {
                    richTextBox2.AppendText(item.Key + ": { ");
                    foreach (var s in item.Value)
                        richTextBox2.AppendText(s + " ");
                    richTextBox2.AppendText("}\n");
                }
            }
            else
            {
                MessageBox.Show("该文法不是LL(1)文法，存在FIRST集合有交集的情况！\n");
            }
        }
    }
    else
    {
        MessageBox.Show("该文法不是LL(1)文法，产生式有误！\n");
    }

}

private void button5_Click(object sender, EventArgs e)
{
    SaveFileDialog
    saveFileDialog = new SaveFileDialog();
    saveFileDialog.Filter = "Text files (*.txt)|*.txt|All files (*.*)|*.*";
    saveFileDialog.FileName = "Grammer.txt"; // 设置默认文件名
    if (saveFileDialog.ShowDialog() == DialogResult.OK)
    {
        string filename = saveFileDialog.FileName;
        File.WriteAllText(filename, richTextBox1.Text);
        MessageBox.Show("文件已成功保存至：" + filename);
    }
}

}