treelang: can we replace 'unsigned char *chars' by 'char *chars'?

[Lemaitre Laurent-r29173]

Hi All,

In file treelang.h structure token_part is defined as follows:
struct token_part GTY(())
{
  location_t location;
  unsigned int charno;
  unsigned int length; /* The value.  */
  const unsigned char *chars;  <-- HERE
};

'unsigned char *chars' is used instead of just 'char *chars'.
Is-there any reason (speed, memory) why 'unsigned' is used?

I am building an autogenerated version of 'treelang' and I am trying
to generate directly 'tree' node in file parse.y. That
is the reasoin why I am asking.

Thanks,

Laurent