[antlr-interest] C# Bug in CharScanner

[Dr. Hartmut Kocher]

I think I found a bug in the C# CharScanner:

 

The rewind() method does not take into account the case insensitive flag.
Therefore, if the scanner is rewound after a wrong prediction, it throws an
exception if the case of a case insensitive token does not match.

 

I think the correct implementation should be:

 

          public virtual void  rewind(int pos)

          {

                inputState.input.rewind(pos);

                //setColumn(inputState.tokenStartColumn);

                if (caseSensitive)

                {

                     cached_LA2 = inputState.input.LA(2);

                     cached_LA1 = inputState.input.LA(1);

                }

                else

                {

                     cached_LA2 = toLower(inputState.input.LA(2));

                     cached_LA1 = toLower(inputState.input.LA(1));

                }

          }

 

Kind regards

 

Dr. Hartmut Kocher

Cortex Brainware GmbH

 

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