starsky2006的专栏

<br />unit uObjectType;<br /> <br />interface<br /> <br />uses uSymbolType;<br /> <br />const<br />    CNT_ObjectTable_MaxCount = 100; //--标识符表的最大长度（容量）<br /> <br />type<br />    //--标识符类型(常量、变量、数组,过程)<br />    TObjectKind = (okConstant,okVariable,okArray,

<br />unit uSymbol;<br />interface<br />uses<br />    SysUtils,uSymbolType,uError;<br />type<br />    TSymbolAnalyzer = class<br />    private<br />        FScript: string;<br />        FChar: char;<br />        FCharPos: integer;<br />        FSymbol: TSy

<br />unit uSymbolType;<br />interface<br />uses<br />    Classes;<br />const<br />    CNT_Ident_MaxLen = 10; //---标识符最长长度<br />    CNT_Number_MaxLen = 14; //---数字允许的最长位数<br />type<br />    //---标识符<br />    TIdent = packed array[1..CNT_Ident_MaxLen] of ch

参考《编译原理（清华版）》中"PL/0语言编译程序"的源代码，重新整理和实现，以提高代码可阅读性和可理解性。

<br />const<br />    a = 10;<br />var<br />    b,c;<br />    procedure p;<br />    begin<br />        c := b + a<br />    end;<br />begin<br />    read(b);<br />    while b # 0 do<br />    begin<br />        call p;<br />        write(2 * c);<br />       

界面<br /><br /><br />object Form1: TForm1<br />  Left = 192<br />  Top = 114<br />  Width = 691<br />  Height = 451<br />  Caption = 'Form1'<br />  Color = clBtnFace<br />  Font.Charset = DEFAULT_CHARSET<br />  Font.Color = clWindowText<br />  Font.Height =

<br />unit uError;<br /> <br />interface<br /> <br />uses<br />    SysUtils;<br />    <br />type<br />    TError = class<br />    public<br />        procedure ReportError(const AMsg: string);    <br />    end;<br /> <br />implementation<br /> <br />proced

<br />unit uErrorInfo;<br /> <br />interface<br /> <br />const<br />    CNT_Error1 = '程序编译失败';<br />    CNT_Error2 = '数值溢出';<br />    CNT_Error3 = '无效字符';<br />    CNT_Error4 = '代码太长';<br />    CNT_Error_1 = 'Error 01:  常数说明中“=”写成“：=”';<br />    CNT_Error_

<br />unit uInterpret;<br /> <br />interface<br /> <br />uses<br />    SysUtils,classes,Dialogs,uCodeType;<br /> <br />type<br />    TInterpret = class<br />    private<br />        FCode: PInstructions; //--代码段<br />        FOutList: TStrings;<br />    pu

<br />unit uCode;<br /> <br />interface<br /> <br />uses<br />    SysUtils,Classes,uSymbolType,uCodeType,uError;<br /> <br />type<br />    TCodes = class<br />    private<br />        FError: TError;<br />        FCode: PInstructions; //--代码表<br />       

<br />unit uGrammar;<br /> <br />interface<br /> <br />uses<br />    SysUtils,Classes,TypInfo,uSymbolType,uSymbol,uObjectType,uCodeType,uCode,uError;<br /> <br />type<br />    TGrammarAnalyzer = class<br />    private<br />        FScript: TSymbolAnalyzer;

<br />unit uCodeType;<br /> <br />interface<br /> <br />const<br />    CNT_LevelMax = 3; //--最大允许的块嵌套层数)<br />    CNT_AddressMax = 2047; //--最大寻址空间<br />    CNT_Code_MaxLen = 200; //--PCODE目标代码表的最大长度（可容纳代码行数）<br /> <br />type<br />    //--PCODE指令类型<br />