yylex.cod

Yacc例子代码

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

(* global definitions: *)
%%

function yylex : Integer;

procedure yyaction ( yyruleno : Integer );
  (* local definitions: *)
%%
begin
  (* actions: *)
  case yyruleno of
%%
  end;
end(*yyaction*);

(* DFA table: *)
%%

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*);