/** <summary>
* The standard method called to automatically emit a token at the
* outermost lexical rule. The token object should point into the
* char buffer start..stop. If there is a text override in 'text',
* use that to set the token's text. Override this method to emit
* custom Token objects.
* </summary>
*
* <remarks>
* If you are building trees, then you should also override
* Parser or TreeParser.getMissingSymbol().
* </remarks>
*/
public virtual IToken Emit()
{
IToken t = new CommonToken( input, state.type, state.channel, state.tokenStartCharIndex, CharIndex - 1 );
t.Line = state.tokenStartLine;
t.Text = state.text;
t.CharPositionInLine = state.tokenStartCharPositionInLine;
Emit( t );
return t;
}
/** <summary>Return a token from this source; i.e., match a token on the char stream.</summary> */
public virtual IToken NextToken()
{
for ( ; ; )
{
state.token = null;
state.channel = TokenChannels.Default;
state.tokenStartCharIndex = input.Index;
state.tokenStartCharPositionInLine = input.CharPositionInLine;
state.tokenStartLine = input.Line;
state.text = null;
if ( input.LA( 1 ) == CharStreamConstants.EndOfFile )
{
IToken eof = new CommonToken((ICharStream)input, CharStreamConstants.EndOfFile, TokenChannels.Default, input.Index, input.Index);
eof.Line = Line;
eof.CharPositionInLine = CharPositionInLine;
return eof;
}
try
{
ParseNextToken();
if ( state.token == null )
{
Emit();
}
else if ( state.token == Tokens.Skip )
{
continue;
}
return state.token;
}
catch (MismatchedRangeException mre)
{
ReportError(mre);
// MatchRange() routine has already called recover()
}
catch (MismatchedTokenException mte)
{
ReportError(mte);
// Match() routine has already called recover()
}
catch ( RecognitionException re )
{
ReportError( re );
Recover( re ); // throw out current char and try again
}
}
}
protected override object GetMissingSymbol( IIntStream input,
RecognitionException e,
int expectedTokenType,
BitSet follow)
{
string tokenText = null;
if ( expectedTokenType == TokenTypes.EndOfFile )
tokenText = "<missing EOF>";
else
tokenText = "<missing " + TokenNames[expectedTokenType] + ">";
CommonToken t = new CommonToken( expectedTokenType, tokenText );
IToken current = ( (ITokenStream)input ).LT( 1 );
if ( current.Type == TokenTypes.EndOfFile )
{
current = ( (ITokenStream)input ).LT( -1 );
}
t.Line = current.Line;
t.CharPositionInLine = current.CharPositionInLine;
t.Channel = DefaultTokenChannel;
t.InputStream = current.InputStream;
return t;
}
