$ ./pm_11137926_str_parse.pl
1..13
ok 1 - <This is simple.>: This|is|simple.
ok 2 - <     This  is   simple. >: This|is|simple.
ok 3 - <This is "so very simple".>: This|is|"so very simple".
ok 4 - <This "is so" very simple.>: This|"is so"|very|simple.
ok 5 - <This 'isn\'t nice.'>: This|'isn\'t nice.'
ok 6 - <This "isn\"t nice.">: This|"isn\"t nice."
ok 7 - <This 'isn\'t nice.'>: This|'isn\'t nice.'
ok 8 - <This "isn\"t nice.">: This|"isn\"t nice."
ok 9 - <This 'isn\\'t nice.'>: This|'isn\\'t|nice.'
ok 10 - <This "isn\\"t nice.">: This|"isn\\"t|nice."
ok 11 - <This 'is not unnice.'>: This|'is not unnice.'
ok 12 - <This "is not unnice.">: This|"is not unnice."
ok 13 - <a "bb cc" d>: a|"bb cc"|d