Added first test case, which always pass and can test eos or bos.\nChanges in the grammar:\n  * added {number,} and {,number} repeat support\n  * set_item to separate character group items from others\n  * new character rule\n  * re-designing char_group sets\n * started handling spaces
Added first test case, which always pass and can test eos or bos.\nChanges in the grammar:\n  * added {number,} and {,number} repeat support\n  * set_item to separate character group items from others\n  * new character rule\n  * re-designing char_group sets\n * started handling spaces