RE: [HACKERS] Postgres' lexer

Leon took it out with a patch that he sent in about ten days ago.  I did
some (very) basic testing, and it seemed to remove the problem of limiting
the token size, which is what I was after.

MikeA

>> -----Original Message-----
>> From: Tom Lane [mailto:tgl@sss.pgh.pa.us]
>> Sent: Tuesday, August 31, 1999 3:58 PM
>> To: Thomas Lockhart
>> Cc: Brook Milligan; Michael.Ansley@intec.co.za; leon@udmnet.ru;
>> pgsql-hackers@postgreSQL.org
>> Subject: Re: [HACKERS] Postgres' lexer 
>> 
>> 
>> Thomas Lockhart <lockhart@alumni.caltech.edu> writes:
>> > I added the <xm> exclusive state to accomodate the possibility of a
>> > unary minus. The change was provoked by Vadim's addition of CREATE
>> > SEQUENCE, which should allow negative numbers for some 
>> arguments. But
>> > this just uncovered the tip of the general problem...
>> 
>> It seems awfully hard and dangerous to try to identify unary minus in
>> the lexer.  The grammar at least has enough knowledge to 
>> recognize that
>> a minus *is* unary and not binary.  Looking into gram.y, I 
>> find that the
>> CREATE SEQUENCE productions handle collapsing unary minus all by
>> themselves!  So in that particular case, there is still no 
>> need for the
>> lexer to do it.  AFAICT in a quick look through gram.y, there are no
>> places where unary minus is recognized that gram.y won't try 
>> to collapse
>> it.
>> 
>> In short, I still think that the whole mess ought to come out of the
>> lexer...
>> 
>>             regards, tom lane
>>