commandline.dpr

语法分析 语法分析

(* lexical analyzer template (TP Lex V3.0), V1.0 3-2-91 AG *)

(* global definitions: *)
{参考lex和yacc第二版实现的对于命令行参数的分析}

//重新定义get_char和unget_char来实现对命令行参数的分析
//注意这里没有实现yylineno和yycolno因为没有意义

program CommandLine.dpr;

{$APPTYPE CONSOLE} //注意别忘了指定控制台模式

uses
  //CommandLex是改写后的LexLib，重定义了get_char, unget_char和put_char三个函数，以便
  //使用命令行参数作为解析对象。
  SysUtils, Classes, CommandLex, Windows;

function yylex: Integer;

  procedure yyaction(yyruleno: Integer);
    (* local definitions: *)

  begin
    (* actions: *)
    case yyruleno of
      1,
        2,
        3:
        begin
          writeln(format('用法是: %s [-help | -h | -? ] [-verbose | -v] [(-file| -f) filename]', [GetCommandLine]));
          return(0);
        end;
      4,
        5:
        writeln('打开Verbose模式');

    end;
  end (*yyaction*);

  (* DFA table: *)

type
  YYTRec = record
    cc: set of Char;
    s: Integer;
  end;

const

  yynmarks = 5;
  yynmatches = 5;
  yyntrans = 14;
  yynstates = 15;

  yyk: array[1..yynmarks] of Integer = (
    { 0: }
    { 1: }
    { 2: }
    { 3: }
    1,
    { 4: }
    2,
    { 5: }
    4,
    { 6: }
    { 7: }
    { 8: }
    { 9: }
    { 10: }
    3,
    { 11: }
    { 12: }
    { 13: }
    { 14: }
    5
    );

  yym: array[1..yynmatches] of Integer = (
    { 0: }
    { 1: }
    { 2: }
    { 3: }
    1,
    { 4: }
    2,
    { 5: }
    4,
    { 6: }
    { 7: }
    { 8: }
    { 9: }
    { 10: }
    3,
    { 11: }
    { 12: }
    { 13: }
    { 14: }
    5
    );

  yyt: array[1..yyntrans] of YYTrec = (
    { 0: }
    (cc: ['-']; s: 2),
    { 1: }
    (cc: ['-']; s: 2),
    { 2: }
    (cc: ['?']; s: 4),
    (cc: ['h']; s: 3),
    (cc: ['v']; s: 5),
    { 3: }
    (cc: ['e']; s: 6),
    { 4: }
    { 5: }
    (cc: ['e']; s: 7),
    { 6: }
    (cc: ['l']; s: 8),
    { 7: }
    (cc: ['r']; s: 9),
    { 8: }
    (cc: ['p']; s: 10),
    { 9: }
    (cc: ['b']; s: 11),
    { 10: }
    { 11: }
    (cc: ['o']; s: 12),
    { 12: }
    (cc: ['s']; s: 13),
    { 13: }
    (cc: ['e']; s: 14)
    { 14: }
    );

  yykl: array[0..yynstates - 1] of Integer = (
    { 0: } 1,
    { 1: } 1,
    { 2: } 1,
    { 3: } 1,
    { 4: } 2,
    { 5: } 3,
    { 6: } 4,
    { 7: } 4,
    { 8: } 4,
    { 9: } 4,
    { 10: } 4,
    { 11: } 5,
    { 12: } 5,
    { 13: } 5,
    { 14: } 5
    );

  yykh: array[0..yynstates - 1] of Integer = (
    { 0: } 0,
    { 1: } 0,
    { 2: } 0,
    { 3: } 1,
    { 4: } 2,
    { 5: } 3,
    { 6: } 3,
    { 7: } 3,
    { 8: } 3,
    { 9: } 3,
    { 10: } 4,
    { 11: } 4,
    { 12: } 4,
    { 13: } 4,
    { 14: } 5
    );

  yyml: array[0..yynstates - 1] of Integer = (
    { 0: } 1,
    { 1: } 1,
    { 2: } 1,
    { 3: } 1,
    { 4: } 2,
    { 5: } 3,
    { 6: } 4,
    { 7: } 4,
    { 8: } 4,
    { 9: } 4,
    { 10: } 4,
    { 11: } 5,
    { 12: } 5,
    { 13: } 5,
    { 14: } 5
    );

  yymh: array[0..yynstates - 1] of Integer = (
    { 0: } 0,
    { 1: } 0,
    { 2: } 0,
    { 3: } 1,
    { 4: } 2,
    { 5: } 3,
    { 6: } 3,
    { 7: } 3,
    { 8: } 3,
    { 9: } 3,
    { 10: } 4,
    { 11: } 4,
    { 12: } 4,
    { 13: } 4,
    { 14: } 5
    );

  yytl: array[0..yynstates - 1] of Integer = (
    { 0: } 1,
    { 1: } 2,
    { 2: } 3,
    { 3: } 6,
    { 4: } 7,
    { 5: } 7,
    { 6: } 8,
    { 7: } 9,
    { 8: } 10,
    { 9: } 11,
    { 10: } 12,
    { 11: } 12,
    { 12: } 13,
    { 13: } 14,
    { 14: } 15
    );

  yyth: array[0..yynstates - 1] of Integer = (
    { 0: } 1,
    { 1: } 2,
    { 2: } 5,
    { 3: } 6,
    { 4: } 6,
    { 5: } 7,
    { 6: } 8,
    { 7: } 9,
    { 8: } 10,
    { 9: } 11,
    { 10: } 11,
    { 11: } 12,
    { 12: } 13,
    { 13: } 14,
    { 14: } 14
    );

var
  yyn: Integer;

label
  start, scan, action;

begin

  start:

  (* initialize: *)

  yynew;

  scan:

  (* mark positions and matches: *)

  for yyn := yykl[yystate] to yykh[yystate] do
    yymark(yyk[yyn]);
  for yyn := yymh[yystate] downto yyml[yystate] do
    yymatch(yym[yyn]);

  if yytl[yystate] > yyth[yystate] then
    goto action; (* dead state *)

  (* get next character: *)

  yyscan;

  (* determine action: *)

  yyn := yytl[yystate];
  while (yyn <= yyth[yystate]) and not (yyactchar in yyt[yyn].cc) do
    inc(yyn);
  if yyn > yyth[yystate] then
    goto action;
  (* no transition on yyactchar in this state *)

(* switch to new state: *)

  yystate := yyt[yyn].s;

  goto scan;

  action:

  (* execute action: *)

  if yyfind(yyrule) then
  begin
    yyaction(yyrule);
    if yyreject then
      goto action;
  end
  else if not yydefault and yywrap then
  begin
    yyclear;
    return(0);
  end;

  if not yydone then
    goto start;

  yylex := yyretval;

end (*yylex*);

begin
  yylex;
  readln;
end.