import java.io.IOException;

%%

%public
%class Scanner
%implements Expression.yyInput

%type boolean
%function advance
%eofval{
  return false;
%eofval}

%{
  /** current input symbol.
    */
  protected int token;

  /** determines current input.
      @return token value or character.
    */
  public int token () {
    return token;
  }

  /** value associated with current input symbol.
    */
  protected Object value;

  public Object value () {
    return value;
  }
%}

comment	= ("#".*)
space	= [\ \t\b\015]+
digit	= [0-9]
integer	= {digit}+
exp	= ([eE]("+"|"-")?{digit}+)
real	= ({digit}+"."{digit}*{exp}?|"."{digit}+{exp}?|{digit}+{exp})

%%

{space}		{ }
{comment}	{ }
{integer}	{ token = Expression.Constant;
		  value = new Integer(yytext()); 
		  return true;
		}
{integer}[lL]	{ token = Expression.Constant;
		  value = new Long(yytext().substring(0, yytext().length()-1));
		  return true;
		}
{real}		{ token = Expression.Constant;
		  value = new Double(yytext());
		  return true;
		}
.|\n		{ token = yytext().charAt(0); return true; }