>> Hi!
Hi, Leon

>> I'm currently fooling around with Postgres's parser, and I must admit
>> some things puzzle me completely. Please tell me what these things in
>> lexer stand for:
>> 
>> {operator}/-[\.0-9]	{
>> 					yylval.str = pstrdup((char*)yytext);
>> 					return Op;
>> 				}
>> Is it an operator followed by mandatory '-' and (dot or digit) ?
I think this is used to recognize an operator followed by a minus or any
single character (the period is escaped, the character can be used to denote
the base of the number) or a single digit.
But check this, I'm not totally sure.

>> And what this stands for:
>> 
>> {identifier}/{space}*-{number}
An identifier followed by any number of spaces, and then a minus, or a
number.  Again, double check this with a reference of some sorts.

>> 
>> What's the meaning of all these?
>> 
You really should get a reference that deals with regular expressions.  My
understanding is (anybody feel free to comment here) that flex uses normal
regular expressions to generate scanners.


Cheers...

MikeA

Fri, 20 Aug 1999 10:56:09 +0200
"Ansley, Michael" <Michael.Ansley@intec.co.za>
RE: [HACKERS] Postgres' lexer 
Ansley, Michael wrote:
...
> >> And what this stands for:
> >>
> >> {identifier}/{space}*-{number}
> An identifier followed by any number of spaces, and then a minus, or a
> number.  Again, double check this with a reference of some sorts.

Well, I studied flex manpage from top to bottom, and almost everything
in Postgres's lexer makes sense. But these "followed by spaces and a
queer minused number" do not. Can someone tell me what do these 
minused single - digit numbers stand for?

-- 
Leon.
---------
"This may seem a bit weird, but that's okay, because it is weird." -
Perl manpage.



Fri, 20 Aug 1999 14:36:20 +0500
Leon <leon@udmnet.ru>
Re: [HACKERS] Postgres' lexer