st: Postfile "forgets" the postfile

[Sebastian Eppner <eppner@uni-potsdam.de>]

Hi,

at some point in my code i define a postfile, in which i want to write
4 variables, say one two three four.

. postfile x one two three four using somedataset, replace

then open a forval loop and after some calculations i want to add new
observations to the postfile, using the code:

. post y (one) (two) (three) (four)

unfortunately, at this point stata tells me:
post x not found
r(111);

So apparently, Stata lost the postfile definition along the way somehow...

I could track down the exact point at which Stata lost the
information, which is a selfwritten ado.
So the problem lies probably in the ado. I suspect the preserve /
restore / clear combination i use in there. I am not an experienced
ado writer, so please help me. the simplified structure of the ado is
like this:

program tuples2, rclass
    version 9
        syntax varlist(min=1 max=1 numeric) [if] [in]
....
preserve
clear

set obs2
.....do some stuff
.....write the results i am interested in into return macros
restore
end


Could this "clear" be responsible for the damage? If yes, is there
another way I can "start from scratch" in the ado file (and in the end
restore the damage done) while NOT hurting the postfile definition?

Thanks for a little help.
Sebastian

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