Re: Escape handling in COPY, strings, psql

Peter Eisentraut wrote:
> Bruce Momjian wrote:
> > I was suggesting ESCAPE 'string' or ESC 'string'.  The marker has to
> > be before the string so scan.l can alter its processing of the string
> > --- after the string is too late --- there is no way to undo any
> > escaping that has happened, and it might already be used by gram.y.
> 
> That pretty much corresponds to my E'string' proposal.  Both are 
> probably equally trivial to implement.

Right.  I think your E'' idea has the benefit of fitting with our
existing X'' and B'' modifiers.  It is also simpler and cleaner to do in
scan.l, so I think your idea is best.

> > I agree with Tom that COPY has to be left unchanged.  The fundamental
> > problem is the representation of NULL values, that I don't think we
> > can do without some escape mechanism.  Single-quote escapes works by
> > doubling them, but once you need to represent something more like
> > null's, I can't think of a solution without escapes.
> 
> Yes, I now realize that COPY has a whole set of different rules anyway, 
> so we can leave that out of this discussion.

Cool.

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