"Delimiter specifies a string whose characters are to be used as the word separator."

Does this mean:
(1) Delimiter specifies a char-set composed of the characters in it;
if a character is 's matches *any* character in 'delimiter' it's a word boundary.
(2) A delimiter can match multiple characters, and the scan is as if done by
string-contains?

I suspect (1) is intended, but it does have the problem mentioned in my
"deprecate or generalize string-tabulate and string-unfold?"
that doesn't handle grapheme clusters etc.

The delimiter should probably be a regex, so maybe deferred to another library.
It strings are allowed should "abc" be interpreted as /[abc]/ or /abc/.
I think the latter is cleaner.
--
	--Per Bothner
xxxxxx@bothner.com   http://per.bothner.com/