I wrote:
> (regexp-split " +" " foo bar baz " #:limit 3 #:trim 'both)
> => ("foo" "bar" "baz")
> (regexp-split " +" " foo bar baz " #:limit 2 #:trim 'both)
> => ("foo" "bar")
Sorry, that last example is wrong of course, but both of these examples
raise an interesting question about how #:limit and #:trim should
interact. To my mind, the top example above is correct. I think the
last result should be "baz", not "baz ".
I guess I'd prefer to think of #:trim as trimming *before* splitting,
instead of trimming empty elements *after* splitting, so:
(regexp-split " +" " foo bar baz " #:limit 3 #:trim 'both)
=> ("foo" "bar" "baz")
(regexp-split " +" " foo bar baz " #:limit 2 #:trim 'both)
=> ("foo" "bar baz")
Note also that if you trim empty elements *after* splitting, then
there's a bad interaction with #:limit if you trim the left side.
Consider:
(regexp-split " +" " foo bar baz " #:limit 3 #:trim 'both)
If we first split, taking into account the limit, we get:
("" "foo" "bar baz ")
and then we trim empty elements from both ends to get the final result:
=> ("foo" "bar baz")
which seems wrong, given that I asked for #:limit 3.
Honestly, this question makes me wonder if the proposed 'regexp-split'
is too complicated. If you want to trim whitespace, how about using
'string-trim-right' or 'string-trim-both' before splitting? It seems
more likely to do what I would expect.
What do you think?
Regards,
Mark
