question: @ Override public Vector whatCanGoHere ( int [ ] state ) { Vector ret = new Vector ( ) ; for ( int i = 0 ; i < fNumElements ; i ++ ) { if ( state [ i + 1 ] == STATE_START ) ret . addElement ( fAllElements [ i ] ) ; } return ret ; }
target:  Check which elements are valid to appear at this point. This method also works if the state is in error, in which case it returns what should have been seen.