/** <summary>
* Given a start and stop index, return a List of all tokens in
* the token type BitSet. Return null if no tokens were found. This
* method looks at both on and off channel tokens.
* </summary>
*/
public virtual IList<IToken> GetTokens( int start, int stop, BitSet types )
{
if ( p == -1 )
{
FillBuffer();
}
if ( stop >= tokens.Count )
{
stop = tokens.Count - 1;
}
if ( start < 0 )
{
start = 0;
}
if ( start > stop )
{
return null;
}
// list = tokens[start:stop]:{Token t, t.getType() in types}
IList<IToken> filteredTokens = new List<IToken>();
for ( int i = start; i <= stop; i++ )
{
IToken t = tokens[i];
if ( types == null || types.Member( t.Type ) )
{
filteredTokens.Add( t );
}
}
if ( filteredTokens.Count == 0 )
{
filteredTokens = null;
}
return filteredTokens;
}
public virtual bool MismatchIsMissingToken( IIntStream input, BitSet follow )
{
if ( follow == null )
{
// we have no information about the follow; we can only consume
// a single token and hope for the best
return false;
}
// compute what can follow this grammar element reference
if ( follow.Member( TokenTypes.EndOfRule ) )
{
BitSet viableTokensFollowingThisRule = ComputeContextSensitiveRuleFOLLOW();
follow = follow.Or( viableTokensFollowingThisRule );
if ( state._fsp >= 0 )
{ // remove EOR if we're not the start symbol
follow.Remove( TokenTypes.EndOfRule );
}
}
// if current token is consistent with what could come after set
// then we know we're missing a token; error recovery is free to
// "insert" the missing token
//System.out.println("viable tokens="+follow.toString(getTokenNames()));
//System.out.println("LT(1)="+((TokenStream)input).LT(1));
// BitSet cannot handle negative numbers like -1 (EOF) so I leave EOR
// in follow set to indicate that the fall of the start symbol is
// in the set (EOF can follow).
if ( follow.Member( input.LA( 1 ) ) || follow.Member( TokenTypes.EndOfRule ) )
{
//System.out.println("LT(1)=="+((TokenStream)input).LT(1)+" is consistent with what follows; inserting...");
return true;
}
return false;
}
/** Given a start and stop index, return a List of all tokens in
* the token type BitSet. Return null if no tokens were found. This
* method looks at both on and off channel tokens.
*/
public virtual List<IToken> GetTokens(int start, int stop, BitSet types)
{
if (_p == -1)
Setup();
if (stop >= _tokens.Count)
stop = _tokens.Count - 1;
if (start < 0)
start = 0;
if (start > stop)
return null;
// list = tokens[start:stop]:{Token t, t.getType() in types}
List<IToken> filteredTokens = new List<IToken>();
for (int i = start; i <= stop; i++)
{
IToken t = _tokens[i];
if (types == null || types.Member(t.Type))
{
filteredTokens.Add(t);
}
}
if (filteredTokens.Count == 0)
{
filteredTokens = null;
}
return filteredTokens;
}
/** <summary>Consume tokens until one matches the given token set</summary> */
public virtual void ConsumeUntil( IIntStream input, BitSet set )
{
//System.out.println("consumeUntil("+set.toString(getTokenNames())+")");
int ttype = input.LA( 1 );
while ( ttype != TokenTypes.EndOfFile && !set.Member( ttype ) )
{
//System.out.println("consume during recover LA(1)="+getTokenNames()[input.LA(1)]);
input.Consume();
ttype = input.LA( 1 );
}
}
