%%

%class scanner
%unicode
%line
%column
%byaccj

%{
/* For more information, please see the jflex manual
   They have explanation as to why we need a reference
   to a parser object. We also will need a cross-reference
   back to the lexer object.*/

	/* store a reference to the parser object */
	private Parser yyparser;

	/* constructor taking an additional parser */
	public scanner (java.io.Reader r, Parser yyparser) {
		this (r);	
		this.yyparser = yyparser;
	}

	/* return the current line number. We need this
	   because yyline is made private and we don't have
	   a mechanism like extern in C. */
	public int getLine() {
		return yyline;
	}

%}

%%
"+"		{return Parser.PLUS;}
"*"		{return Parser.TIMES;}
"("		{return Parser.LPAREN;}
")"		{return Parser.RPAREN;}
\r|\n|\r\n	{return Parser.CR;}
[0-9]+		{yyparser.yylval = new ParserVal(Integer.parseInt(yytext()));return Parser.INT;}
[ \t]		{;}