Leex regex problem

That did the trick, thank You very much.

Here is the modified version…

TAG        = (\[[^\]]*\])

iex> :pgn_lexer.string '[Tag1 "Value1"][Tag2 "Value2"]{comment}' 
{:ok,
 [
   {:tag, 1, '[Tag1 "Value1"]'},
   {:tag, 1, '[Tag2 "Value2"]'},
   {:comment, 1, '{comment}'}
 ], 1}

And as mentionned, the short version works as well

TAG        = \[[^\]]*\]