🚀 go-pugleaf

Hi,

   G++ 1.32 seems to have a problem.  Consider the following program,
which uses regular expression matching in libg++:

----------------------------------------
#include <String.h>

Regex  rx_param ("[()\\[a-zA-Z_0-9*\\]]+",1);

main () {
   String param = "foobar[]";

   if (param.matches (rx_param)) {
      printf ("works\n");
   }
   else {
      printf ("fails\n");
   }
      
}
----------------------------------------

The problem here is trying to match a literal ']' within a character
class (the constructor for rx_param seems to believe it is the
trailing ']' for the character class).  When I looked at the sparc ASM
output, it didn't reduce the '\\' to '\' at all, i.e., the asm output
looked like:

.text
	.align 0
LC0:
	.ascii "[()\\[a-zA-Z_0-9*\\]]+\0"

which doesn't work correctly.

Unfortunately, using a single backslash, i.e.,

"[()\[a-zA-Z_0-9*\]]+"

DOES strip the backslash off, so that this leaves 

"[()[a-zA-Z_0-9*]]+"

which is clearly not going to work (since the regular expression
scanner will mistake the first ']' for the end of the character class.

So the question remains: how does one get a single backslash before
a ']'?

Doug