/**
* Function VisitReadStmt : it reads the new value for our variable
* and checks both if the variable was previous declared and it has the same
* type as the read value
* Param : stmt with the new value for our variable
*/
public Object VisitReadStmt(Stmt.Read stmt)
{
/* If the variable already exists and it is the proper type we update the symble table */
if (SymbleTable.ContainsKey(stmt.Token.Text))
{
String x = Console.ReadLine();
Value value = CheckReadStatement(x, stmt.Token, SymbleTable[stmt.Token.Text].Type);
SymbleTable[stmt.Token.Text] = value;
return(null);
}
/* Otherwise throw an error */
throw new RuntimeError(stmt.Token, "Variable not previous declared.");
}
/**
* Function VisitReadStatement : it checks that the variable we are reading
* already exists and it is not the loop counter inside a loop
* Param : read statement to check
*/
public object VisitReadStmt(Stmt.Read stmt)
{
/* Error if the variable was not previous declared */
if (!SymbleTypeTable.ContainsKey(stmt.Token.Text))
{
throw new TypeError(stmt.Token, "Cannot read to a variable before it was declared.");
}
/* Error if we try to read the loop counter inside the loop */
if (illegalAssignments.Contains(stmt.Token.Text))
{
throw new TypeError(stmt.Token, "Cannot assign to " + stmt.Token.Text + " in a for loop where it is used as a loop counter.");
}
return(null);
}
