ch1-02.l

YACC与LEX教程 英文原版(中文书附代码与答案)

%{
/*
 * this sample demonstrates (very) simple recognition:
 * a verb/not a verb.
 */

%}
%%

[\t ]+		/* ignore white space */ ;

is |
am |
are |
were |
was |
be |
being |
been |
do |
does |
did |
will |
would |
should |
can |
could |
has |
have |
had |
go		{ printf("%s: is a verb\n", yytext); }

[a-zA-Z]+ 	{ printf("%s: is not a verb\n", yytext); }

.|\n		{ ECHO; /* normal default anyway */ }
%%

main()
{
	yylex();
}