Ref. Draft #4 published: 2017/6/25

- Extra "string-every" after first sentence in description of
  string-every.

- I may be missing something obvious, but the rationale for excluding
  UTF-32 analogues of the procedures like string->utf8 and
  utf8->string is unclear to me.

- The Rationale section notes that there are no performance guarantees
  for any procedures of this SRFI, but the descriptions of
  string-length and string-ref mention O(1) requirements.  Are these
  meant to be exceptions, or are the requirements left over from an
  earlier SRFI?

- It may be useful to list the "not in SRFI 13" procedures in the
  comparison with SRFI 13 in the Rationale section.

- In the description of string-join, there is the sentence:

  string-list is a list of strings and/or strings.

  I think it should just say list of strings.

- Near the end of the Sample Implementation section, there seems to be
  a parentheses problem in the code snippet:

  (import (except scheme)
    string->list string-fill!))

Regards,

-chaw