I often use CHOP 0 to generate a null record before each input record to control the flow in another pipeline. I wish this had been true way, way back when negative numbers were added to CHOP! I would have suggested that -0 be a valid way to specify the end of the record, to generate a null record *after* each input record.
For anybody else who's puzzled over how to do this, the obvious answer that finally struck me is just to use the largest supported number, 2**31-1 (though this does have the inconvenience of requiring NUMERIC DIGITS 10 to compute if you don't want to depend on your fingers to type it correctly). Out of curiosity, though, is that a hard limit, or is it possible to have a record longer than that? Not being in system support anymore, I don't have a playground where I can define arbitrarily large machines to try creating one. ¬R
