130242014058+吴伟铭+第2次实验
一、实验目的
1．熟悉体系结构的风格的概念
2．理解和应用管道过滤器型的风格。
3、理解解释器的原理
4、理解编译器模型
二、实验环境
硬件：
软件：Python或任何一种自己喜欢的语言
三、实验内容
1、实现“四则运算”的简易翻译器。
结果要求：
1）实现加减乘除四则运算，允许同时又多个操作数，如：2+3*5-6 结果是11
2）被操作数为整数，整数可以有多位
3）处理空格
4）输入错误显示错误提示，并返回命令状态“CALC”
图1 实验结果示例
加强练习：
1、有能力的同学，可以尝试实现赋值语句，例如x=2+3*5-6，返回x=11。（注意：要实现解释器的功能，而不是只是显示）
2、尝试实现自增和自减符号，例如x++
3、采用管道-过滤器（Pipes and Filters）风格实现解释器
图2 管道-过滤器风格
图 3 编译器模型示意图
本实验，实现的是词法分析和语法分析两个部分。
import wx # begin wxGlade: extracode # end wxGlade class MyFrame(wx.Frame): def __init__(self, *args, **kwds): # begin wxGlade: MyFrame.__init__ kwds["style"] = wx.DEFAULT_FRAME_STYLE wx.Frame.__init__(self, *args, **kwds) self.text_ctrl_1 = wx.TextCtrl(self, -1, "",style=wx.TE_READONLY) self.button_37 = wx.Button(self, -1, "1") self.button_38 = wx.Button(self, -1, "2") self.button_39 = wx.Button(self, -1, "3") self.button_40 = wx.Button(self, -1, "+") self.button_41 = wx.Button(self, -1, "4") self.button_42 = wx.Button(self, -1, "5") self.button_43 = wx.Button(self, -1, "6") self.button_44 = wx.Button(self, -1, "-") self.button_46 = wx.Button(self, -1, "7") self.button_45 = wx.Button(self, -1, "8") self.button_47 = wx.Button(self, -1, "9") self.button_48 = wx.Button(self, -1, "x") self.button_49 = wx.Button(self, -1, "C") self.button_50 = wx.Button(self, -1, "0") self.button_51 = wx.Button(self, -1, "=") self.button_52 = wx.Button(self, -1, "/") self.__set_properties() self.__do_layout() self.Bind(wx.EVT_BUTTON, self.bu1, self.button_37) self.Bind(wx.EVT_BUTTON, self.bu2, self.button_38) self.Bind(wx.EVT_BUTTON, self.bu3, self.button_39) self.Bind(wx.EVT_BUTTON, self.bu_plus, self.button_40) self.Bind(wx.EVT_BUTTON, self.bu4, self.button_41) self.Bind(wx.EVT_BUTTON, self.bu5, self.button_42) self.Bind(wx.EVT_BUTTON, self.bu6, self.button_43) self.Bind(wx.EVT_BUTTON, self.bu_min, self.button_44) self.Bind(wx.EVT_BUTTON, self.bu7, self.button_46) self.Bind(wx.EVT_BUTTON, self.bu8, self.button_45) self.Bind(wx.EVT_BUTTON, self.bu9, self.button_47) self.Bind(wx.EVT_BUTTON, self.bu_mul, self.button_48) self.Bind(wx.EVT_BUTTON, self.bu_clear, self.button_49) self.Bind(wx.EVT_BUTTON, self.bu0, self.button_50) self.Bind(wx.EVT_BUTTON, self.bu_result, self.button_51) self.Bind(wx.EVT_BUTTON, self.bu_chu, self.button_52) # end wxGlade self.Show(True) def __set_properties(self): # begin wxGlade: MyFrame.__set_properties self.SetTitle("Python Calculater by CYG") self.text_ctrl_1.SetMinSize((400, 50)) self.button_37.SetMinSize((100, 50)) self.button_38.SetMinSize((100, 50)) self.button_39.SetMinSize((100, 50)) self.button_40.SetMinSize((100, 50)) self.button_41.SetMinSize((100, 50)) self.button_42.SetMinSize((100, 50)) self.button_43.SetMinSize((100, 50)) self.button_44.SetMinSize((100, 50)) self.button_46.SetMinSize((100, 50)) self.button_45.SetMinSize((100, 50)) self.button_47.SetMinSize((100, 50)) self.button_48.SetMinSize((100, 50)) self.button_49.SetMinSize((100, 50)) self.button_50.SetMinSize((100, 50)) self.button_51.SetMinSize((100, 50)) self.button_52.SetMinSize((100, 50)) # end wxGlade def __do_layout(self): # begin wxGlade: MyFrame.__do_layout sizer_2 = wx.BoxSizer(wx.VERTICAL) sizer_3 = wx.BoxSizer(wx.VERTICAL) grid_sizer_1 = wx.GridSizer(4, 4, 0, 0) sizer_3.Add(self.text_ctrl_1, 0, 0, 0) grid_sizer_1.Add(self.button_37, 0, 0, 0) grid_sizer_1.Add(self.button_38, 0, 0, 0) grid_sizer_1.Add(self.button_39, 0, 0, 0) grid_sizer_1.Add(self.button_40, 0, 0, 0) grid_sizer_1.Add(self.button_41, 0, 0, 0) grid_sizer_1.Add(self.button_42, 0, 0, 0) grid_sizer_1.Add(self.button_43, 0, 0, 0) grid_sizer_1.Add(self.button_44, 0, 0, 0) grid_sizer_1.Add(self.button_46, 0, 0, 0) grid_sizer_1.Add(self.button_45, 0, 0, 0) grid_sizer_1.Add(self.button_47, 0, 0, 0) grid_sizer_1.Add(self.button_48, 0, 0, 0) grid_sizer_1.Add(self.button_49, 0, 0, 0) grid_sizer_1.Add(self.button_50, 0, 0, 0) grid_sizer_1.Add(self.button_51, 0, 0, 0) grid_sizer_1.Add(self.button_52, 0, 0, 0) sizer_3.Add(grid_sizer_1, 1, wx.EXPAND, 0) sizer_2.Add(sizer_3, 1, wx.EXPAND, 0) self.SetSizer(sizer_2) sizer_2.Fit(self) self.Layout() # end wxGlade def bu1(self, event): # wxGlade: MyFrame.<event_handler> self.text_ctrl_1.AppendText("1") event.Skip() def bu2(self, event): # wxGlade: MyFrame.<event_handler> self.text_ctrl_1.AppendText("2") event.Skip() def bu3(self, event): # wxGlade: MyFrame.<event_handler> self.text_ctrl_1.AppendText("3") event.Skip() def bu_plus(self, event): # wxGlade: MyFrame.<event_handler> self.num1=self.text_ctrl_1.GetValue() self.op="+" self.text_ctrl_1.Clear() event.Skip() def bu4(self, event): # wxGlade: MyFrame.<event_handler> self.text_ctrl_1.AppendText("4") event.Skip() def bu5(self, event): # wxGlade: MyFrame.<event_handler> self.text_ctrl_1.AppendText("5") event.Skip() def bu6(self, event): # wxGlade: MyFrame.<event_handler> self.text_ctrl_1.AppendText("6") event.Skip() def bu_min(self, event): # wxGlade: MyFrame.<event_handler> self.num1=self.text_ctrl_1.GetValue() self.op="-" self.text_ctrl_1.Clear() event.Skip() def bu7(self, event): # wxGlade: MyFrame.<event_handler> self.text_ctrl_1.AppendText("7") event.Skip() def bu8(self, event): # wxGlade: MyFrame.<event_handler> self.text_ctrl_1.AppendText("8") event.Skip() def bu9(self, event): # wxGlade: MyFrame.<event_handler> self.text_ctrl_1.AppendText("9") event.Skip() def bu_mul(self, event): # wxGlade: MyFrame.<event_handler> self.num1=self.text_ctrl_1.GetValue() self.op="x" self.text_ctrl_1.Clear() event.Skip() def bu_clear(self, event): # wxGlade: MyFrame.<event_handler> self.text_ctrl_1.Clear() event.Skip() def bu0(self, event): # wxGlade: MyFrame.<event_handler> self.text_ctrl_1.AppendText("0") event.Skip() def bu_chu(self, event): # wxGlade: MyFrame.<event_handler> self.num1=self.text_ctrl_1.GetValue() self.op="/" self.text_ctrl_1.Clear() event.Skip() def bu_result(self, event): # wxGlade: MyFrame.<event_handler> self.num2=self.text_ctrl_1.GetValue() num1=int(self.num1) num2=int(self.num2) if self.op=="+": self.text_ctrl_1.SetValue(str(num1+num2)) elif self.op=="-": self.text_ctrl_1.SetValue(str(num1-num2)) elif self.op=="x": self.text_ctrl_1.SetValue(str(num1*num2)) elif self.op=="/": self.text_ctrl_1.SetValue(str(num1/num2)) event.Skip() # end of class MyFrame if __name__ == "__main__": app=wx.App(False) myframe=MyFrame(None) app.MainLoop()
