isverb.l

来自「语法分析 语法分析」· L 代码 · 共 46 行

%{
 {*
    下面的例子改编自lex和yacc第二版
    简单的识别什么是动词 

 *}
 program IsVerb;

{$APPTYPE CONSOLE}

uses
  SysUtils, LexLib;
%}
%%

[\t ]+		{* 忽略空格 *};

is |
am |
are |
were |
was |
be |
being |
been |
do |
does |
did |
will |
would |
should |
can |
could |
has |
have |
had |
go		writeln(format('%s是动词', [yytext])); 

[a-zA-Z]+ 	writeln(format('%s不是动词', [yytext])); 

.|\n		ECHO;
%%

begin
  yylex;
end.