wordcnt.dpr

语法分析 语法分析

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

(* global definitions: *)
{*
    下面的例子改编自lex和yacc第二版
    单词计数

    编译：lex wordcount wordcnt.dpr
 *}
program WordCnt;

{$APPTYPE CONSOLE}

uses
  SysUtils, LexLib, Dialogs;
var
  CharCount, WordCount, LineCount: integer;

function yylex: Integer;

  procedure yyaction(yyruleno: Integer);
    (* local definitions: *)
  begin
    (* actions: *)
    case yyruleno of
      1:
        begin
          inc(WordCount);
          inc(CharCount, yyleng);
        end;
      2:
        begin
          inc(CharCount);
          inc(LineCount);
        end;
      3:
        inc(CharCount);
    end;
  end (*yyaction*);

  (* DFA table: *)

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

const

  yynmarks = 5;
  yynmatches = 5;
  yyntrans = 8;
  yynstates = 6;

  yyk: array[1..yynmarks] of Integer = (
    { 0: }
    { 1: }
    { 2: }
    1,
    3,
    { 3: }
    2,
    { 4: }
    3,
    { 5: }
    1
    );

  yym: array[1..yynmatches] of Integer = (
    { 0: }
    { 1: }
    { 2: }
    1,
    3,
    { 3: }
    2,
    { 4: }
    3,
    { 5: }
    1
    );

  yyt: array[1..yyntrans] of YYTrec = (
    { 0: }
    (cc: [#1..#8, #11..#31, '!'..#255]; s: 2),
    (cc: [#9, ' ']; s: 4),
    (cc: [#10]; s: 3),
    { 1: }
    (cc: [#1..#8, #11..#31, '!'..#255]; s: 2),
    (cc: [#9, ' ']; s: 4),
    (cc: [#10]; s: 3),
    { 2: }
    (cc: [#1..#8, #11..#31, '!'..#255]; s: 5),
    { 3: }
    { 4: }
    { 5: }
    (cc: [#1..#8, #11..#31, '!'..#255]; s: 5)
    );

  yykl: array[0..yynstates - 1] of Integer = (
    { 0: } 1,
    { 1: } 1,
    { 2: } 1,
    { 3: } 3,
    { 4: } 4,
    { 5: } 5
    );

  yykh: array[0..yynstates - 1] of Integer = (
    { 0: } 0,
    { 1: } 0,
    { 2: } 2,
    { 3: } 3,
    { 4: } 4,
    { 5: } 5
    );

  yyml: array[0..yynstates - 1] of Integer = (
    { 0: } 1,
    { 1: } 1,
    { 2: } 1,
    { 3: } 3,
    { 4: } 4,
    { 5: } 5
    );

  yymh: array[0..yynstates - 1] of Integer = (
    { 0: } 0,
    { 1: } 0,
    { 2: } 2,
    { 3: } 3,
    { 4: } 4,
    { 5: } 5
    );

  yytl: array[0..yynstates - 1] of Integer = (
    { 0: } 1,
    { 1: } 4,
    { 2: } 7,
    { 3: } 8,
    { 4: } 8,
    { 5: } 8
    );

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

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
  if paramcount = 1 then
  begin
    if not FileExists(ParamStr(1)) then
    begin
      Writeln('输入文件不存在');
      Halt;
    end;
    AssignFile(yyinput, ParamStr(1));
    reset(yyinput);
  end;
  yylex;
  Writeln(format('字符数:%d 单词数:%d 行数:%d', [CharCount, WordCount,
    LineCount]));
  readln;
end.