I copied my last on this to Tech Support, who do refer it as a bug, and
have referred it to the StataCorp developers. So, I agree with Joseph
and it's already happening.
Nick
[email protected]
Joseph Coveney
That's not good. Although it leaves a missing value in its wake, its
messing up
of the string variable might go unnoticed, especially if the user
expected
occasional blanks for other reasons.
It seems like something for StataCorp to remedy before others get bit
during
activities like Rose's. In the interim, I guess the best protection is
to
get into the habit of using -assert- liberally.
Nick Cox wrote:
What is happening is that -- when v3 is a string variable and not empty
--
replace v3 = subinstr(v3, "", "", 1)
zaps v3. That is, -v3- ends up empty.
I am not sure why that is happening. For example, replacing empty
strings by empty strings looks like an example of no change to me. Also
even if "" is a substring of a non-empty string, it still has a
complement.
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/