public void Clone(MyIDictionary <K, V> toClone)
{
dict = new Dictionary <K, V>();
foreach (K k in toClone.KeySet())
{
this.dict[k] = toClone.Get(k);
}
}
public override int Evaluate(MyIDictionary <string, int> symTab)
{
try
{
return(symTab.Get(id));
}
catch (InvalidKeyMyDictionaryException)
{
throw new UndeclaredVariableException("Exception: Undeclared variable: " + id + ".");
}
}
public ProgramState Execute(ProgramState state)
{
MyIDictionary <int, MyPair <string, StreamReader> > fileTable = state.GetFileTab();
MyIDictionary <string, int> symTable = state.GetSymTab();
// 1. evaluate var_file_id to a value. If any error occurs, stop the execution
int value;
try
{
value = var_file_id.Evaluate(symTable);
}
catch (ExpressionEvaluationException e)
{
throw new MyStatementExecutionException("The file is not opened for reading.");
}
// 2. Use the value to get the entry into the file table and get the associated StreamReader
// object. If there is no entry in the file table for the value, we stop the execution
StreamReader sr;
try
{
sr = fileTable.Get(value).GetSecond();
}
catch (InvalidKeyMyDictionaryException)
{
throw new MyStatementExecutionException("Error. There is no entry (" + value + ") in the file table.");
}
// 3. call the Close() method
try
{
sr.Close();
}
catch (IOException e)
{
throw new MyStatementExecutionException("IO Error: " + e.ToString());
}
// 4. delete the entry from the file table
try
{
fileTable.Remove(value);
}
catch (InvalidKeyMyDictionaryException)
{
throw new MyStatementExecutionException("Error. There is no entry (" + value + ") in the file table.");
}
// 5. return
return(null);
}
public ProgramState Execute(ProgramState state)
{
MyIDictionary <int, MyPair <string, StreamReader> > fileTable = state.GetFileTab();
MyIDictionary <string, int> symTable = state.GetSymTab();
// 1. evaluate var_file_id to a value
int value;
try
{
value = var_file_id.Evaluate(symTable);
}
catch (ExpressionEvaluationException e)
{
throw new MyStatementExecutionException("Cannot read from var " + var_file_id.ToString() + ".");
}
// 2. get the StreamReader object associated in the file table. If there is no entry associated
// with that value in the file table, we stop the execution
StreamReader sr;
try
{
sr = fileTable.Get(value).GetSecond();
}
catch (InvalidKeyMyDictionaryException)
{
throw new MyStatementExecutionException("Error. There is no entry (" + value + ") in the file table.");
}
// 3. Read a line from the file using the ReadLine() method of the StreamReader object.
// If line is null create a zero int value, otherwise translate the string into an int value
int read;
try
{
string line = sr.ReadLine();
read = line.Equals(null) ? 0 : Int32.Parse(line);
}
catch (IOException)
{
throw new MyStatementExecutionException("Error on reading from file.");
}
// 4. Add a new mapping (var_name, int value computed at the previous step) into the sym-table.
// If var_name exists in sym-table, update its associated value instead of adding a new mapping
symTable.Put(var_name, read);
// 5. return
return(null);
}
public override int Evaluate(MyIDictionary <string, int> symbolTable)
{
return(symbolTable.Get(name));
}