P1 - Quarta

1. 

    public void nextToken() {
        char ch;
        
        while (  (ch = input[tokenPos]) == ' ' || ch == '\r' ||
                 ch == '\t' || ch == '\n')  
          tokenPos++;
        if ( ch == '\0') 
          token = Symbol.EOF;
        else
          if ( ch >= '0' && ch <= '9' ) {
                // get a number
             valorNumero = 0;
             int i = 0;
             while ( Character.isDigit( input[tokenPos] ) ) {
               valorNumero = valorNumero*10 + (input[tokenPos] - ´0´);
               tokenPos++;
               i++;
             }
             token = Symbol.NUMERO;
             if ( i > 5 )
               error.signal("Number out of limits");
                
          } else {
            tokenPos++;
            switch ( ch ) {
              case '+' :
                token = Symbol.PLUS;
                break;
              case '*' :
                token = Symbol.MULT;
                break;
              default :
                if ( ch >= 'a' && ch <= 'z' ) {
                  token = Symbol.LETRA;
                  valorIdent = ch;
                }
                else
                  error.signal("Invalid Character: '" + ch + "'");
            }
          }
    }
    
2. 
a)
class Program {
   private Vector arrayVariable;
   private CompositeComand compositeCommand;
}

class PrintCommand extends Command {
   private Vector exprList;
}

class Variable {
   private String name;
   private Type type;
}


b) 

private Program program() {
   Vector arrayVariable = new Vector();
   
   while  ( token == Symbol.INTEGER || token == Symbol.BOOLEAN ) 
      arrayVariable.addElement( varDec() );
   return new Program( arrayVariable, compositeCommand() );
}

private PrintCommand printCommand() {
  Vector exprList = new Vector();
  Expr e;
  
  while ( token != Symbol.SEMICOLON ) {
     exprList.addElement( e = orExpr() );
     if ( e.getType() != Type.integerType )
        error("Somente expressões inteiras podem ser impressas");
     }
  return new PrintCommand( exprList );
}

private Variable varDec() {
  Variable v;
  Type t = type();
  if ( token != Symbol.IDENT ) error();
  String name = stringValue;
  if ( symbolTable.get(name) != null )
     error("Variável " + name " já foi declarada");
  nextToken();
  symbolTable.put(name, v = new Variable(name, t));
  return v;
}

  
3. 

void genC() {
  Enumeration e = exprList.elements();
  while ( e.hasMoreElements() ) {
    Expr expr = (Expr ) e.nextElement();
    sop( "printf\"\%d\\n\", ");
    expr.genC();
    sop( ");");
  }
}