Lisp grammar in yacc

( 1 1)
23 23 23
ui ui

%%
sexpr: atom                 {printf("matched sexprn");}
    | list
    ;
list: '(' members ')'       {printf("matched listn");}
    | '('')'                {printf("matched empty listn");}
    ;
members: sexpr              {printf("members 1n");}
    | sexpr members         {printf("members 2n");}
    ;
atom: ID                    {printf("IDn");}
    | NUM                   {printf("NUMn");}
    | STR                   {printf("STRn");}
    ;
%%

program: slist;

slist: slist sexpr | sexpr;

( 1 1

%{
    #include <stdio.h>
    #include "a.yacc.tab.h"
    int linenumber;
    extern int yylval;
%}
%%
n                         { linenumber++; }
[0-9]+                     { yylval = atoi(yytext); return NUM; }
"[^"n]*"               { return STR; }
[a-zA-Z][a-zA-Z0-9]*       { return ID; }
.
%%

(1 1 1)
NUM
matched sexpr
NUM
matched sexpr
NUM
matched sexpr
(1 1
NUM
matched sexpr
NUM
matched sexpr

)     { return RPAREN; }
(     { return LPAREN; }

program: sexpr*

program :  /* empty */
        | program sexpr
        ;

program: (sexpr)*;

sexpr: list
    |  atom            {Console.WriteLine("matched sexpr");}
    ;

list:
   '('')'              {Console.WriteLine("matched empty list");}
   | '(' members ')'   {Console.WriteLine("matched list");}

    ;

members: (sexpr)+      {Console.WriteLine("members 1");};

atom: Id               {Console.WriteLine("ID");}
    | Num              {Console.WriteLine("NUM");}
    ;


Num: ( '0' .. '9')+;
Id: ('a' .. 'z' | 'A' .. 'Z')+;
Whitespace : ( ' ' | 'r' 'n' | 'n' | 't' ) {Skip();};