$re_revdiablo =  qr[ 
    (?:                             # group, no capture
        [^\w\'\$!,.-]               # on anything not in your list
    |                                
        (?: 
            (?<= \D ) [.,] )        # or . or, if preceded by a non numeric
        | 
            (?: [.,] (?= \D | $)    # or . or, if followed by a non numeric or EOL
        ) 
     )+                             # 1 or more
]x;