Hung-Jen Wang <[email protected]>
> Tuesday, September 10, 2002, Nick [Cox] wrote:
> To echo and expand on my earlier posting in this thread,
> program def myexpl
> version 6
> syntax [ , myopt(str) ]
> if trim("`myopt'") != "" {
> unab myopt : `myopt'
> }
> else local myopt
> Nick
> If -myopt- is desired to be empty (which is the source of this
problem),
> the above program does not work with Stata 6 executable. It is
because
> Stata 6 does not accept empty (either "()" or "( )") as a valid
> "string" for -myopt-, therefore spitting out the message
> "myopt() invalid" when encounters. It seems the only way around is
to
> use "passthru" instead of string or varlist as the option value
type, as
> suggested by Weihua Guan.
OK, but you've got me lost in these subtleties.
As I see it, if you want -myopt()- to be empty, you don't
need to invoke it. That is easy enough, interactively
and also in some wider program.
What's the complication forbidding that?
Nick
[email protected]
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