private Surface.Expr Factor()
{
Surface.Expr expr;
switch (lookahead.Type)
{
case SchoolLexer.LPAREN:
Match(SchoolLexer.LPAREN);
expr = Expr();
Match(SchoolLexer.RPAREN);
break;
case SchoolLexer.NUM:
string numberText = lookahead.Text;
expr = new Surface.Number(Int32.Parse(numberText));
Consume();
break;
default:
throw new ParserException("expecting number; found " + lookahead);
}
return(expr);
}
Core.Expr Surface.IExprVisitor <Core.Expr> .Visit(Surface.Number number)
{
return(new Core.Number(number.Value));
}
object Surface.IExprVisitor <object> .Visit(Surface.Number number)
{
Console.Write(number.Value);
return(null);
}
