[developers] Stack overflow in generator unpack-edge

[Stephan Oepen]

> [...] where generating without packing produces the more informative
> usual warning about a possibly recursive rule, which is then immediately
> visible in the generator chart.

i am glad this is at least partially resolved.  i suspect it is another
instance of the `recursive' packing problem, i.e. packing a phrase into
one of its daughters.  we used to run into this every now and again in
parsing, and at least PET now protects against this problem.  i believe
we typically conclude that this situation exposes a bug in the grammar,
and that it would be good to give more explicit feed-back.  even though
i cannot recall it happening before, i suspect there is no real reason
the generator should always steer clear of this problem.

> [...] sensible grammar developers will of course remember to examine
> problematic generation examples with packing disabled.

i honestly think you are being too harsh on yourself!  a lot depends on
experience, so just allow yourself some time.

                                                      all best  -  oe

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