# match when between unescaped reverse parens                                   
# ..or start/end of string                                                      
@script = split
/
 (?<=           #lookbehind (only remove whitespaces)                                   
  (^|           #for start of string or                                         
   (?<!\\) \) ) #unescaped rparen followed by                                   
  .*?           #stingy other chars                                             
 )

 \s+            #some spaces, to be removed                            

 (?=            #lookahead                                                      
  .*?           #stingy other chars                                             
  ($|           #end of string or                                               
   (?<!\\) \( ) #unescaped lparen                                               
 )
/xs, $script;