Re: dollar-quoting in psql and in general

Philip Warner wrote:

> While trying to understand dollar-quoting, I found the following in psql:
>
> select $a$ hello $a$;
>
> behaves as expected, but psql does not like
>
> select $a$ \ $a$;
> or
> select $a$ \\ $a$;
>
> Should it? How should a dollar-quote handle:
>
> $a$ \$a\$a $a$
>
> ?
>
>
andrew=# select $a$ \ $a$;
?column?
----------
\
(1 row)

andrew=# select $a$ \\ $a$;
?column?
----------
\\
(1 row)

It is behaving as *I* expect, and as designed. \ is not magical inside
dollar quotes, and if it were it would defeat the whole purpose of
having them.

Dollar quotes are really designed for strings that are reparsed - most
typically function bodies. The strings inside them are therefore totally
opaque, and there is no escape character. Otherwise, if we wanted the
plpgsql parsers, say, to see \ we'd have to write \\, and the idea was
to get away from \\, \', '' and friends.

cheers

andrew