%{
#include <string.h>
#include "syntax_tree.h"
#include "y.tab.h"

/* defined in pc.y (pc.c) */
extern YYSTYPE yylval;

/* defined in syntax_tree.c */
extern Tree mkNum(int);
extern Tree mkStr(char *);
extern Tree mkSym(char *);

%}
s	[ \t\r\n]
n	[0-9]
a	[A-Za-z]
an	({a}|{n})
%%
{s}+		{ }
var		{ return VAR; }
return		{ return RETURN; }
if		{ return IF; }
else		{ return ELSE; }
while		{ return WHILE; }
"=="		{ return EQEQ; }
"!="		{ return EXEQ; }
"<="		{ return LTEQ; }
">="		{ return GTEQ; }
{n}+		{ yylval = mkNum(atoi(yytext)); return NUM; }
(['][^'\n]*['])+ {yylval = mkStr(strdup(yytext)); return STR; }
{a}{an}*	{ yylval = mkSym(strndup(yytext,8)); return SYM; }
.		{ return yytext[0]; }

^"//".*$ 	{ }
%%

int yywrap() { return 1; }