/// <summary>
/// Retrieves a token from the input string. This method can be called multiple
/// time to get tokens further on the input string.
/// </summary>
/// <returns>The token</returns>
public TerminalToken RetrieveToken()
{
dfa.Reset();
Location startLocation = input.Location.Clone();
AcceptInfo acceptInfo = null;
if (input.Position >= input.Text.Length)
{
return(new TerminalToken(SymbolCollection.EOF,
SymbolCollection.EOF.Name,
startLocation));
}
State newState = dfa.GotoNext(input.ReadChar());
while (newState != null)
{
if (newState is EndState)
{
acceptInfo = new AcceptInfo((EndState)newState, input.Location.Clone());
}
if (input.IsEof())
{
newState = null;
}
else
{
newState = dfa.GotoNext(input.ReadChar());
}
}
if (acceptInfo == null)
{
int len = input.Location.Position - startLocation.Position;
string text = input.Text.Substring(startLocation.Position, len);
return(new TerminalToken(SymbolCollection.ERROR, text, startLocation));
}
else
{
input.Location = acceptInfo.Location;
int len = acceptInfo.Location.Position - startLocation.Position;
string text = input.Text.Substring(startLocation.Position, len);
return(new TerminalToken(acceptInfo.State.AcceptSymbol, text, startLocation));
}
}
/// <summary>
/// Retrieves a token from the input string. This method can be called multiple
/// time to get tokens further on the input string.
/// </summary>
/// <returns>The token</returns>
public TerminalToken RetrieveToken()
{
dfa.Reset();
Location startLocation = input.Location.Clone();
AcceptInfo acceptInfo = null;
if (input.Position >= input.Text.Length)
{
return new TerminalToken(SymbolCollection.EOF,
SymbolCollection.EOF.Name,
startLocation);
}
State newState = dfa.GotoNext(input.ReadChar());
while (newState != null)
{
if (newState is EndState)
{
acceptInfo = new AcceptInfo((EndState)newState,input.Location.Clone());
}
if (input.IsEof())
newState = null;
else
newState = dfa.GotoNext(input.ReadChar());
}
if (acceptInfo == null)
{
int len = input.Location.Position - startLocation.Position;
string text = input.Text.Substring(startLocation.Position,len);
return new TerminalToken(SymbolCollection.ERROR,text,startLocation);
}
else
{
input.Location = acceptInfo.Location;
int len = acceptInfo.Location.Position - startLocation.Position;
string text = input.Text.Substring(startLocation.Position,len);
return new TerminalToken(acceptInfo.State.AcceptSymbol,text,startLocation);
}
}