On Jul 30, 2008, at 13:10, Tom Lane wrote:
Yes, that was essentially my point. "arbitrary string of text" types are probably fairly rare, since one can just use text or citext or varchar.Good point --- so new members of STRING category aren't going to be thatcommon, except for domains which apparently aren't bothering people anyway. I'll go ahead and make the change. (I think it's just a trivial change in find_coercion_pathway, and everything else should Just Work. If it turns out not to be trivial maybe we should reconsider.)
Wow. Really nice, Tom. Thanks!The attached patch has all the tests I added to my svn version against 8.3, and for which I had to write 60 additional cast functions. With your changes, I had to add only two more:
CREATE OR REPLACE FUNCTION citext(boolean) RETURNS citext AS 'booltext' LANGUAGE 'internal' IMMUTABLE STRICT; CREATE OR REPLACE FUNCTION citext(inet) RETURNS citext AS 'SELECT text( $1 )::citext' LANGUAGE SQL IMMUTABLE STRICT;So the I/O casts are working beautifully. This is true even for ENUMs, which I couldn't get to magically cast with a function in 8.3. Thank you!
If you don't want so many cast tests, I can remove all but a few of them. I wrote them for all the core user-visible types I could identify so that I could see how they behaved with text and then make citext work the same way. Such is not as important in HEAD, thanks to the I/O casting, so let me know if you want me to cut down on the number of tests (I was particularly uncertain about the xml type, since --with-libxml won't always be true, I expect).
The other change in this patch is the addition of functions to make various string-comparison functions behave case-insensitively. I've started with all those that I was aware of from the previous documentation, and I've made them behave case-insensitively by writing SQL functions to hack it in. Ideally these would be done in C, but that started to get beyond my abilities. Suggestions welcome.
The only other thing I wanted to look at doing with citext was to look for any other string-comparison functions I might have missed and do the same for them. Otherwise, I think we're golden.
Many thanks, David
citext_casting.patch.gz
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